46 results on '"Li-yan, Liu"'
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2. Al2O3 coating on BaLi2Ti6O14 surface to boost its stability and rate performance
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Ying Xie, Xiaodong Wang, Li-yan Liu, Chen-Feng Guo, Bing Zheng, Hai-Tao Yu, and Ting-Feng Yi
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010302 applied physics ,Battery (electricity) ,Materials science ,Scanning electron microscope ,Process Chemistry and Technology ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Anode ,Coating ,Chemical engineering ,Transmission electron microscopy ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,engineering ,Particle size ,0210 nano-technology ,Layer (electronics) - Abstract
BaLi2Ti6O14, a promising anode material for lithium-ion battery application, was successfully prepared by a sol-gel method. To improve the structural stability and electrochemical performance of the materials, an ionic conductive Al2O3 layer was introduced. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the particles become smaller and distribute more uniformly because of the coating, and possible mechanism was discussed. Our experiments further showed that BLTO-4 sample has the best electrochemical performance. Furthermore, excessive coating will lead to a decrease of reversible capacity, because Al2O3 has no electrochemical activity. The charge and discharge capacities of BLTO-4 are 174.9 and 175.9 mAh g−1 after 50 cycles at 0.2 C, which are much higher than those of the pure sample (107.3 and 108.4 mAh g−1). Even at 10 C, BLTO-4 still delivers a reversible specific capacity of 98.6 mAh g−1 after 1000 cycles. The good cyclic stability and rate performance of BLTO-4 can be attributed to the reduced particle size and the advantages of the Al2O3 coating layer, which is favorable for the enhancement of the structural stability and the reduction of the charge transfer resistance of the materials.
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- 2020
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3. Characteristics of indoor and outdoor fine particles in heating period at urban, suburban, and rural sites in Harbin, China
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Yuxuan Liang, Yi-Fan Li, Yu Zhuang, Wei-Wei Song, Yujie Xu, Amadou Hima Boubacar, Linan Ma, Xueying Wang, Li-Yan Liu, Wenxu Fang, Guangnian Chen, and Yehao Ji
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China ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,Combustion ,complex mixtures ,01 natural sciences ,Heating ,chemistry.chemical_compound ,Nitrate ,Environmental Chemistry ,Coal ,Cities ,Particle Size ,Sulfate ,Chemical composition ,0105 earth and related environmental sciences ,Pollutant ,Total organic carbon ,Air Pollutants ,business.industry ,General Medicine ,Infiltration (HVAC) ,Pollution ,Carbon ,chemistry ,Air Pollution, Indoor ,Environmental chemistry ,Environmental science ,Particulate Matter ,Seasons ,business ,Environmental Monitoring - Abstract
Concurrent indoor–outdoor fine particulate matter (PM2.5) measurements were conducted at urban, suburban, and rural sites in Harbin, a megacity in the northeast of China. Chemical constituents of indoor–outdoor PM2.5 were determined. Infiltration factors (FINF) of all sites were calculated according to the indoor to outdoor (I/O) ratios of PM2.5 based on the regression analysis. Linear discriminant analysis (LDA) is applied to determine the indoor–outdoor relationship. Secondary organic carbon (SOC) was calculated on the basis of organic carbon to elemental carbon (OC/EC) ratios. The mean concentrations of indoor and outdoor PM2.5 were 166.4 ± 32.5 μg/m3 and 228.4 ± 83.7 μg/m3, respectively, during the heating period. OC/EC and potassium ion to elemental carbon (K+/EC) ratios verified that biomass was an important source in Harbin especially for rural sites. The nitrate to sulfate (NO3−/SO42−) ratio indicates the higher contribution of traffic emissions in urban sites. Cr was the only species that exceeded the guidelines of WHO 2002, which was mainly emitted from coal and oil combustion. SOC/OC and NO3−/SO42− ratios, and ion-balanced acidity (the ratio of cation to anion, R+/−) showed a large urban–rural and indoor–outdoor difference. The highest SOC/OC ratio was found at urban sites, up to 38.3% for indoors. SOC/OC ratios and R+/− values of indoor environments were higher, which is attributed to the conducive condition of forming the secondary pollutants during the heating period. The results of LDA indicated that the distributions of the chemical components of PM2.5 at three sites were statistically dissimilar.
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- 2019
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4. The effects of grafting density and charge fraction on the properties of ring polyelectrolyte brushes: a molecular dynamics simulation study
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Li-Xiang Liu, Gang Xia, Li-Yan Liu, Qing-Hai Hao, and Bing Miao
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inorganic chemicals ,chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Charge (physics) ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ring (chemistry) ,Grafting ,01 natural sciences ,Polyelectrolyte ,0104 chemical sciences ,Molecular dynamics ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Monomer ,chemistry ,Chemical physics ,Materials Chemistry ,Physical and Theoretical Chemistry ,Counterion ,0210 nano-technology ,Scaling - Abstract
Using molecular dynamics simulations, the flexible ring polyelectrolyte chains tethered to a planar substrate and immersed in good solvents are investigated systematically. Two sets of simulations are performed to explore the effects of grafting density and charge fraction, respectively. Both the monovalent and trivalent counterions are considered. The height of the brush H follows a scaling relation with grafting density (~σgν) and charge fraction (~fν). The values of the exponents are different from those of the linear counterparts. Through a careful analysis on the distributions of monomers and counterions, pair correlation functions of monomer-monomer and monomer-counterion, as well as the fractions of trivalent counterions in four states, the equilibrium structures of the ring PE brushes are examined in detail. Furthermore, a brief comparison with the ‘equivalent’ linear brush is carried out. Also, our results can serve as a guide for improving the performance of ring polyelectrolyte brushes as unique surface modifiers.
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- 2019
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5. Phthalates in infant cotton clothing: Occurrence and implications for human exposure
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Wei-Wei Song, Zhi Zhang, Li-Yan Liu, Wan-Li Ma, Ed Sverko, Yu Sun, Yi-Fan Li, Zi-Feng Zhang, and Hai-Ling Li
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China ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Dibutyl phthalate ,Phthalic Acids ,Infant health ,010501 environmental sciences ,Risk Assessment ,01 natural sciences ,Clothing ,Toxicology ,chemistry.chemical_compound ,parasitic diseases ,Humans ,Environmental Chemistry ,Medicine ,Cotton Fiber ,Waste Management and Disposal ,0105 earth and related environmental sciences ,business.industry ,Infant, Newborn ,Phthalate ,Infant ,Infant exposure ,Environmental Exposure ,Infant clothing ,Pollution ,chemistry ,Human exposure ,Environmental Pollutants ,Detection rate ,business ,Environmental Monitoring - Abstract
Clothing easily adsorbed the chemicals in the environment, and became a source of human exposure to chemicals. However, large contacted surface area and long exposure duration have elevated human exposure to chemicals from clothing, such as phthalates. Among them, cotton clothing, which infants prefer to wear, has been proven to adsorb phthalates more easily than other fabrics. While infants are developing, they are easily affected by phthalates. In this study, in order to study accumulation of phthalates in infant cotton clothing during the whole process from production to the first wearing, 24 infant cotton clothing samples were collected from shopping malls in Harbin, China. High detection rates and concentrations suggest that phthalates in the environment are widely adsorbed to infant cotton clothing, and traditional laundering for infant clothing cannot remove phthalates completely. The median concentration of the total phthalates was 4.15 μg/g. Di-(2-ethylhexyl) phthalate (DEHP) has become the dominant phthalate. For the estimated daily intakes (EDIs) for infants, dibutyl phthalate (DBP) had the highest contribution, followed by di-iso-butyl phthalate (DiBP) and DEHP. Dermal absorption has become the main route of infant exposure to phthalates, and ingestion contributed very little. The result of comparing with the EDIs via dermal absorption from house air and dust suggests that clothing plays an important role of dermal absorption exposure to phthalates. For risk assessment, the carcinogenic risk of BBP and DEHP indicates that the level of DEHP in infant cotton clothing might pose potential adverse effects to infant health.
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- 2019
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6. Measurement and modeling the gas/particle partitioning of organochlorine pesticides (OCPs) in atmosphere at low temperatures
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Wan-Li Ma, Li-Yan Liu, Li-Na Qiao, Ning-Zheng Zhu, Wei-Wei Song, Yi-Fan Li, and Zi-Feng Zhang
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Environmental Engineering ,010504 meteorology & atmospheric sciences ,Condensation ,Sampling (statistics) ,010501 environmental sciences ,Atmospheric temperature range ,Particulates ,01 natural sciences ,Pollution ,Partition coefficient ,Atmosphere ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,Particle ,Partition (number theory) ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
The gas/particle (G/P) partition of organochlorine pesticides (OCPs) has been widely investigated and well documented, but rare at low temperature. In this study, seventy-four pairs of air samples in two sampling sites in northeastern China at a wide ambient temperature range of ~63 °C (−40 to +23 °C) were simultaneously collected in both gaseous and particulate phases and eighteen OCPs in these samples were measured and analyzed, among which, partition quotient (KP) values for fifteen OCPs were determined. Seven models including those have never been used for OCPs were applied to predict the values of KP, and the results were compared with the monitoring data for the fifteen OCPs. It was found out that, L-M-Y model provided advantages over the other models, with the best agreement to the monitoring data for analyzed OCPs (90.1 ± 11.1% data points within ±1 log unit, RMSE: 0.53 ± 0.18). The predicted maximum partition (MP) domain for eleven OCPs was observed with high values of their logarithm of octanol-air partition coefficient (log KOA > 12.5), where the log KP values become a constant (−1.53), indicating that the G/P partition of OCPs is in steady state but not the equilibrium. The Li-Ma-Yang (L-M-Y model) model, considering the wet and dry depositions of particles, elucidates the necessity of non-equilibrium term for the OCPs at low temperature. These results indicate that the L-M-Y model is valid for OCPs, which renders it highly promising for describing the partition behaviors in atmosphere for SVOCs, particularly at low temperature. An equation to calculate the condensation temperature TC was also derived, which gave a new understanding on the situation of chemicals with equal distribution between gaseous and particulate phases of OCPs and other similar SVOCs, especially in Polar Regions.
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- 2019
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7. Organophosphate flame retardants in college dormitory dust of northern Chinese cities: Occurrence, human exposure and risk assessment
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Wei-Wei Song, Hai-Ling Li, Ed Sverko, Yi-Fan Li, Wan-Li Ma, Yu Sun, Zi-Feng Zhang, Chun-Yan Huo, and Li-Yan Liu
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Male ,China ,Environmental Engineering ,Universities ,010504 meteorology & atmospheric sciences ,010501 environmental sciences ,Risk Assessment ,01 natural sciences ,chemistry.chemical_compound ,Humans ,Environmental Chemistry ,Risk threshold ,Cities ,Health risk ,Waste Management and Disposal ,Female students ,Flame Retardants ,0105 earth and related environmental sciences ,Air Pollutants ,Organophosphate ,Dust ,Environmental Exposure ,Pollution ,Organophosphates ,chemistry ,Human exposure ,Air Pollution, Indoor ,Environmental chemistry ,Housing ,Environmental science ,Female ,Risk assessment ,Environmental Monitoring - Abstract
Organophosphate flame retardants (OPFRs) are widely added to consumer products and building materials, which may pose potential health risk to humans. But information on their contamination and human exposure in the indoor environment especially dormitories in northern China is rare. In this study, twelve OPFRs were investigated in college dormitory dust that collected from Harbin, Shenyang, and Baoding, in northern China. Indoor dust samples were also collected from homes and public microenvironments (PMEs) in Harbin for comparison. The median ∑OPFR concentrations in dormitory dust in Shenyang samples (8690 ng/g) were higher than those in Baoding (6540 ng/g) and Harbin (6190 ng/g). The median ∑OPFR concentrations in home dust (7150 ng/g) were higher than in dormitory and PME dust (5340 ng/g) in Harbin. Tris(2‑chloroethyl) phosphate (TCEP) and tris (2-chloroisopropyl) phosphate (TCIPP) were the most abundant chlorinated OPFRs, while triphenyl phosphate (TPHP) and tris(2‑butoxyethyl) phosphate (TBOEP) were the dominant non-chlorinated OPFRs. The daily intakes of ∑OPFR were estimated, with the median values for female students (2.45 ng/kg-day) higher than those for male students (2.15 ng/kg-day) while were similar to adults (2.45 ng/kg-day) in homes. The estimated daily intakes (EDI) of these OPFRs from indoor dust in Harbin were all below the recommended values. The calculated non-carcinogenic hazard quotients (10−8–10−3) from OPFRs were much lower than the theoretical risk threshold. Meanwhile, carcinogenic risk (CR) of tri‑n‑butyl phosphate (TNBP), TCEP, tris(2‑ethylhexyl) phosphate (TEHP), and tris(1,3‑dichloroisopropyl) phosphate (TDCIPP) were also estimated. The highest carcinogenic risk of TCEP for gender-specific and age-specific category range from 1.75 × 10−7 to 2.46 × 10−7 from exposure to indoor dust indicated a low potential carcinogenic risk for human exposure.
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- 2019
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8. Determination of Polycyclic Aromatic Hydrocarbons and Their Methylated Derivatives in Sewage Sludge from Northeastern China: Occurrence, Profiles and Toxicity Evaluation
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Rashid Mohammed, Yi-Fan Li, Li-Yan Liu, Wan-Li Ma, Wei-Wei Song, Anatoly N. Nikolaev, Zi-Feng Zhang, Ze Kan, and Chao Jiang
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Quality Control ,China ,010504 meteorology & atmospheric sciences ,Me-PAHs and PAHs ,Pharmaceutical Science ,Organic chemistry ,010501 environmental sciences ,01 natural sciences ,Methylation ,Article ,Analytical Chemistry ,chemistry.chemical_compound ,QD241-441 ,Neoplasms ,Drug Discovery ,Toxicity Tests ,Soil Pollutants ,Physical and Theoretical Chemistry ,Polycyclic Aromatic Hydrocarbons ,Chromatography, High Pressure Liquid ,0105 earth and related environmental sciences ,Pollutant ,Sewage ,risk assessment ,Agriculture ,source apportionment ,sludge ,chemistry ,Chemistry (miscellaneous) ,Environmental chemistry ,Toxicity ,Molecular Medicine ,Environmental science ,Pyrene ,Cancer risk ,Sludge ,Environmental Monitoring - Abstract
This paper assesses the occurrence, distribution, source, and toxicity of polycyclic aromatic hydrocarbons (PAHs), and their methylated form (Me-PAHs) in sewage sludge from 10 WWTPs in Northeastern China was noted. The concentrations of ∑PAHs, ∑Me-PAHs ranged from 567 to 5040 and 48.1 to 479 ng.g−1dw, which is greater than the safety limit for sludge in agriculture in China. High and low molecular weight 4 and 2-ring PAHs and Me-PAHs in sludge were prevalent. The flux of sludge PAHs and Me-PAHs released from ten WWTPs, in Heilongjiang province, was calculated to be over 100 kg/year. Principal component analysis (PCA), diagnostic ratios and positive matrix factorization (PMF) determined a similar mixed pyrogenic and petrogenic source of sewage sludge. The average values of Benzo[a]pyrene was below the safe value of 600 ng.g−1 dependent on an incremental lifetime cancer risk ILCR of 10−6. Sludge is an important source for the transfer of pollutants into the environment, such as PAHs and Me-PAHs. Consequently, greater consideration should be given to its widespread occurrence.
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- 2021
9. Treatment of particle/gas partitioning using level III fugacity models in a six-compartment system
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Li-Na Qiao, Robie W. Macdonald, Jining Liu, Peng-Tuan Hu, Meng Qin, Chongguo Tian, Lili Shi, Anatoly N. Nikolaev, Yi-Fan Li, Li-Yan Liu, Linjun Zhou, and Pu-Fei Yang
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Flux ,02 engineering and technology ,010501 environmental sciences ,Atmospheric sciences ,01 natural sciences ,Soil ,Environmental Chemistry ,Fugacity ,Compartment (pharmacokinetics) ,0105 earth and related environmental sciences ,Aerosols ,Air Pollutants ,Steady state ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Particulates ,Pollution ,020801 environmental engineering ,Partition coefficient ,Environmental science ,Particle ,Level iii ,Gases - Abstract
In this paper, two level III fugacity models are developed and applied using an environmental system containing six compartments, including air, aerosols, soil, water, suspended particulate matters (SPMs), and sediments, as a “unit world”. The first model, assumes equilibrium between air and aerosols and between water and SPMs. These assumptions lead to a four-fugacity model. The second model removes these two assumptions leading to a six-fugacity model. The two models, compared using four PBDE congeners, BDE-28, -99, −153, and −209, with a steady flux of gaseous congeners entering the air, lead to the following conclusions. 1. When the octanol-air partition coefficient (KOA) is less than 1011.4, the two models produce similar results; when KOA > 1011.4, and especially when KOA > 1012.5, the model results diverge significantly. 2. Chemicals are in an imposed equilibrium in the four-fugacity model, but in a steady state and not necessary an equilibrium in the six-fugacity model, between air and aerosols. 3. The results from the six-fugacity model indicate an internally consistent system with chemicals in steady state in all six compartments, whereas the four-fugacity model presents an internally inconsistent system where chemicals are in equilibrium but not a steady state between air and aerosols. 4. Chemicals are mass balanced in air and aerosols predicted by the six-fugacity model but not by the four-fugacity model. If the mass balance in air and aerosols is achieved in the four-fugacity model, the condition of equilibrium between air and aerosols will be no longer valid.
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- 2020
10. Self-assembly of polyelectrolyte diblock copolymers within mixtures of monovalent and multivalent counterions
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Hong-Ge Tan, Jing-Qi Yang, Li-Xiang Liu, Qing-Hai Hao, Tong Wei, Li-Yan Liu, and Zhong-Xun Yu
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chemistry.chemical_classification ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrostatics ,01 natural sciences ,Micelle ,Polyelectrolyte ,0104 chemical sciences ,Molecular dynamics ,chemistry ,Chemical engineering ,Copolymer ,Lamellar structure ,Self-assembly ,Physical and Theoretical Chemistry ,Counterion ,0210 nano-technology - Abstract
In this study, the self-assembly behavior of polyelectrolyte (PE) diblock copolymers in solutions containing mixtures of monovalent and multivalent counterions was investigated using molecular dynamics simulation. The properties of the assembled micelles and counterion condensations at different charge fractions of multivalent ions have been discussed. The bridging effect of multivalent ions induces the electrostatic correlations of the PE chains, leading to the fusion of large micelles and the formation of bulky aggregates. Notably, lamellar and well-organized face-centered cubic (FCC) arrangements of the assembled micelles were observed in the mixture of monovalent and trivalent ions. At large fractions of multivalent ions, cylindrical and lamellar precipitates composed of the assembled micelles were formed owing to the inter-connecting coronas. The mixtures of monovalent and multivalent counterions allow the regulation of the electrostatic interactions and tuning of the properties in assembled micelles.
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- 2020
11. New equation to predict size-resolved gas-particle partitioning quotients for polybrominated diphenyl ethers
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Anatoly N. Nikolaev, Li-Na Qiao, Peng-Tuan Hu, Wei-Wei Song, Robie W. Macdonald, Wan-Li Ma, Peng-Hao Su, Chongguo Tian, Li-Yan Liu, Zhiguo Cao, Zi-Feng Zhang, and Yi-Fan Li
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chemistry.chemical_classification ,021110 strategic, defence & security studies ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,Particulates ,01 natural sciences ,Pollution ,Polybrominated diphenyl ethers ,chemistry ,Monitoring data ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,Partition (number theory) ,Organic matter ,Waste Management and Disposal ,Quotient ,0105 earth and related environmental sciences - Abstract
Gas/particle (G/P) partition quotients of semi-volatile organic compounds (SVOCs) for bulk air have been widely discussed in experimental and theoretical contexts, but research on size-resolved G/P partition quotients (KPi) are scarce and limited in scope. To investigate G/P partition behavior of polybrominated diphenyl ethers (PBDEs) for size-segregated particles in the atmosphere, 396 individual size-segregated particulate samples (36 batches × 11 size-ranges), and 108 pairs of concurrent gaseous and bulk particulate samples were collected in Harbin, China. A steady-state equation based on bulk particles is derived to determine G/P partition quotients of PBDEs for size-segregated particles, which depends on the organic matter contents of size-segregated particles (fOMi). This equation can well predict KPi with knowledge of bulk partition quotient (KPS), ambient temperature, and fOMi, the results of which match well with monitoring data in Harbin and other published data collected in Shanghai and Guangzhou of China and Thessaloniki of Greece, and remedies a defect of over-estimate KPi for high-brominated PBDEs by the previous equation. In particular, the new equation contributes to obtaining the PBDEs concentrations in all atmospheric phase from partial phase, then provides a credible path to evaluate healthy exposure dose from the airborne PBDEs, by co-utilization with exposure models.
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- 2020
12. Self-assembly of polyelectrolyte diblock copolymers at monovalent and multivalent counterions
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Hong-Ge Tan, Gang Xia, Qing-Hai Hao, Zhao-Jie Feng, and Li-Yan Liu
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chemistry.chemical_classification ,Valence (chemistry) ,Materials science ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Micelle ,Polyelectrolyte ,0104 chemical sciences ,Divalent ,Molecular dynamics ,chemistry ,Chemical physics ,Copolymer ,Self-assembly ,Counterion ,0210 nano-technology - Abstract
In this work, the self-assembly behaviors of diblock copolymers consisting of one hydrophobic block and one ionizable polyelectrolyte (PE) block in the presence of monovalent and multivalent counterions are systematically discussed through molecular dynamics simulation. Copolymers are molded as bead-spring chains and the ions are explicitly considered. First, the self-assembled structures of symmetrical block copolymers at different charge fractions are analyzed in detail. Spherical hydrophobic cores are favored by all of the micelles. The effect of counterion valence is much more noticeable at high values of charge fraction. When the PE blocks are fully charged, the presence of multivalent counterions preferably provokes the formation of macroscopic structures. A precipitant spherical micelle is generated in the presence of divalent counterions. Special shapes of coronas are created in the presence of trivalent ions, and a remarkable one dimensional macroscopic cylindrical aggregation of micelles forms; the whole assembly is not typical core-shell micelles, but rather a cylinder with alternating spherical micelles arranged perpendicular to the cylinder axis. The self-assemblies with different lengths of fully charged PE blocks are also discussed. Surprisingly, in the presence of divalent counterions, two dimensional in-plane macroscopic aggregation of micelles is realized when the proportion of PE blocks is larger than 1/2; the self-assembled spherical micelles locate approximately in the same plane to form an inter-linked network. One dimensional aggregation of micelles in the presence of trivalent counterions is maintained with an increased proportion of the PE block. Owing to the dominant intra- and inter-condensation of divalent and trivalent counterions, respectively, two and one dimensional macroscopic aggregation of the micelles is achieved. Our findings indicate that varying the counterion valence is a powerful mechanism to tune the properties of self-assemblies, and the bridging effect introduced by multivalent counterions is the key parameter for the aggregation of the micelles.
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- 2019
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13. Morphological Response of a Spherical Polyelectrolyte Brush to Solvent Quality and Electrostatic Interaction Strength
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Hong-Ge Tan, Bing Miao, Qing-Hai Hao, Gang Xia, Xiao-Hui Niu, and Li-Yan Liu
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inorganic chemicals ,chemistry.chemical_classification ,Morphology (linguistics) ,Materials science ,Polymers and Plastics ,Diffusion ,Organic Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Radial distribution function ,01 natural sciences ,Polyelectrolyte ,0104 chemical sciences ,Inorganic Chemistry ,Solvent ,Molecular dynamics ,chemistry ,Chemical physics ,Materials Chemistry ,Counterion ,0210 nano-technology ,Shape factor - Abstract
We study surface morphologies of a spherical polyelectrolyte brush in the presence of trivalent counterions using molecular dynamics simulations. Solvent quality and electrostatic interaction strength are varied to generate a series of structures. Through a careful analysis on snapshots of morphologies, shape factor of tethered chains, and monomer–monomer pair correlation function we find a nonmonotonic dependence of surface morphology on electrostatic strength, which represents clearly the electrostatic correlation effect mediated by the multivalent counterions. Due to the very importance of counterions, we further study the correlation effect by classifying counterions into four states, calculating the monomer–counterion pair correlation function and diffusion coefficient of counterions. Our simulation results clearly demonstrate that ordered patterns can be induced by the electrostatic correlation effect in the presence of trivalent counterions, which is absent in the system with monovalent ions. Also,...
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- 2018
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14. PAHs in Chinese atmosphere Part I: Concentration, source and temperature dependence
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Yi-Fan Li, Wan-Li Ma, Hongliang Jia, Li-Yan Liu, and Meng Yang
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,Coal combustion products ,010501 environmental sciences ,Seasonality ,medicine.disease ,Atmospheric sciences ,01 natural sciences ,Atmosphere ,Environmental chemistry ,medicine ,Environmental science ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
The study on atmospheric polycyclic aromatic hydrocarbons (PAHs) in China has regional and global significance to understand the large scale atmospheric transport of PAHs. In this study, 16 US EPA priority PAHs were analyzed in more than 500 pairs of gas and particle phases samples, which were collected on the same schedule on a weekly basis from August 2008 to July 2009 at 11 urban sites (6 northern cities and 5 southern cities) across China. The average concentration was 239 ± 329 ng/m3 and 165 ± 164 ng/m3 for the northern cities and the southern cities, respectively. Different seasonal variations of atmospheric PAHs were observed between northern cities and southern cities, which were mainly caused by the different temperature effects in winter. Identified by principal component analysis, coal combustion and vehicle exhaust were the major sources of atmospheric PAHs in northern and southern cities of China, respectively. The temperature dependences of atmospheric PAHs were also different, which were caused by the different influences of temperature on identified sources. To our knowledge, this is the first comprehensive study to report the difference with concentrations, seasonal variations, sources and temperature dependences of atmospheric PAHs between northern cities and southern cities in China.
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- 2018
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15. Occurrence and source apportionment of atmospheric halogenated flame retardants in Lhasa City in the Tibetan Plateau, China
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Wei-Wei Song, Wan-Li Ma, Yi-Xing Yuan, Yi-Fan Li, Li-Yan Liu, Wen-Long Li, Zi-Feng Zhang, and Chun-Yan Huo
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geography ,Environmental Engineering ,Plateau ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Contribution function ,010501 environmental sciences ,Dechlorane plus ,01 natural sciences ,Pollution ,chemistry.chemical_compound ,Polybrominated diphenyl ethers ,chemistry ,Environmental chemistry ,Environmental behavior ,Correlation analysis ,Environmental Chemistry ,Environmental science ,Potential source ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
Active air samples were collected in Lhasa, one of the highest cities in the world (3650m above sea level) located in the Tibetan Plateau, and were analyzed for 38 halogenated flame retardants (HFRs), including polybrominated diphenyl ethers (PBDEs), non-PBDE brominated flame retardants (NBFRs) and dechlorane plus (DPs). The median concentrations of PBDEs, NBFRs and DPs were 40, 23 and 0.21pg/m3, respectively. Correlation analysis indicated the common source and/or similar environmental behavior for several HFRs. The Clausius-Clapeyron equation was applied to diagnose the sources of lower molecular weight HFRs (LMW-HFRs), which suggested that the gaseous LMW-HFRs at Lhasa were more controlled by regional or long-range atmospheric transport rather than the temperature-driven evaporation from local contaminated surfaces. Finally, the potential source contribution function model was applied to assess the influences of air parcels on the atmospheric concentrations of HFRs in Lhasa, which suggested that the sources of higher molecular weight HFRs (HMW-HFRs) were mostly originated from local emissions, while the others were originated from long-range atmospheric transport.
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- 2017
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16. Occurrence and fate of benzotriazoles UV filters in a typical residential wastewater treatment plant in Harbin, China
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Li-Yan Liu, Fu-Jie Zhu, Xue Zhao, Wei-Wei Song, Zi-Feng Zhang, Wan-Li Ma, Yi-Fan Li, and Lei Xu
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Pollution ,China ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,Wastewater ,010501 environmental sciences ,Toxicology ,Waste Disposal, Fluid ,01 natural sciences ,Rivers ,Effluent ,0105 earth and related environmental sciences ,media_common ,Pollutant ,Sewage ,010401 analytical chemistry ,General Medicine ,Triazoles ,0104 chemical sciences ,Environmental chemistry ,Environmental science ,Water treatment ,Sewage treatment ,Seasons ,Aeration ,Surface water ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Benzotriazoles (BTs) UV filters are widely used as ultraviolet absorbents for our daily products, which received increasing attention in the past decades. Residential wastewater treatment plant (WWTP) is both an important sink for wastewater and a key pollution source for receiving water for these chemicals. In this study, pretreatment and gas chromatography-tandem mass spectrometry analysis method were developed to determine the occurrence and fate of 9 BTs UV filters in wastewater and sludge from the WWTP with anaerobic-oxic treatment process (A/O) and biological aerated filter treatment process (BAF). Totally, 81 wastewater samples and 11 sludge samples were collected in four seasons. In wastewater, UV-326 and UV-329 were frequently detected, while the highest mean concentrations were detected for UV-234 and UV-329. The concentrations were in the range ofLOQs up to several hundred nanograms per liter. The removal efficiency of BTs UV filters was85% in A/O process and 60-77% in BAF process except for UV-350, which was more difficult to remove with lower removal efficiencies of 33.3% for both A/O and BAF. All the target chemicals except for UV-320 were detected in sludge samples with the mean concentration ranging from 0.90 ng/g to 303.39 ng/g. There was no significant difference with concentrations and removal efficiency among different seasons. Higher detection frequency and concentration of BTs UV filters in downstream of the receiving water system indicated the contribution of effluent of the WWTP. Compared with other rivers, the lower concentrations in surface water in the Songhua River indicated light pollution status with of BTs UV filters.
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- 2017
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17. Occurrence, sources and human exposure assessment of SCCPs in indoor dust of northeast China
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Hing Man Chan, Li-Yan Liu, Chong-Jing Gao, Wan-Li Ma, Chun-Yan Huo, Hai-Ling Li, Li-Hua Liu, Wen-Long Li, and Yi-Fan Li
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China ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Factor score ,010501 environmental sciences ,Toxicology ,Risk Assessment ,01 natural sciences ,Human health ,Chlorinated paraffins ,Environmental risk ,Hydrocarbons, Chlorinated ,Humans ,Daily exposure ,0105 earth and related environmental sciences ,Inhalation Exposure ,Significant difference ,Infant ,Dust ,General Medicine ,Pollution ,Carbon ,Paraffin ,Human exposure ,Air Pollution, Indoor ,Child, Preschool ,Environmental chemistry ,Environmental science ,Environmental Monitoring - Abstract
Short-chain chlorinated paraffins (SCCPs) are widely used chemicals in household products and might cause adverse human health effects. However, limited information is available on the occurrence of SCCPs in indoor environments and their exposure risks on humans. In this study the concentrations, profiles and human exposure of SCCPs in indoor dust from five different indoor environments, including commercial stores, residential apartments, dormitories, offices and laboratories were characterized. The SCCPs levels ranged from 10.1 to 173.0 μg/g, with the median and mean concentration of 47.2 and 53.6 μg/g, respectively. No significant difference was found on concentrations among the five microenvironments. The most abundant compounds in indoor dust samples were homologues of C 13 group, Cl 7 group and N 20 (N is the total number of C and Cl) group. In the five microenvironments, commercial stores were more frequently exposed to shorter carbon chained and higher chlorinated homologues. Three potential sources for SCCPs were identified by the multiple linear regression of factor score model and correspondence analysis. The major sources of SCCPs in indoor dust were technical mixtures of CP–42 (42% chlorine, w/w) and CP–52 b (52% chlorine, w/w). The total daily exposure doses and hazard quotients (HQ) were calculated by the human exposure models, and they were all below the reference doses and threshold values, respectively. Monte Carlo simulation was applied to predict the human exposure risk of SCCPs. Infants and toddlers were at risk of SCCPs based on predicted HQ values, which were exceeded the threshold for neoplastic effects in the worst case. Our results on the occurrences, sources and human exposures of SCCPs will be useful to provide a better understanding of SCCPs behaviors in indoor environment in China, and to support environmental risk evaluation and regulation of SCCPs in the world.
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- 2017
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18. PAHs in Chinese atmosphere Part II: Health risk assessment
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Hongliang Jia, Fu-Jie Zhu, Meng Yang, Wan-Li Ma, Li-Yan Liu, and Yi-Fan Li
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Adult ,China ,Adolescent ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Risk Assessment ,Atmosphere ,Reference level ,Air Pollution ,Neoplasms ,Humans ,Cities ,Polycyclic Aromatic Hydrocarbons ,Child ,0105 earth and related environmental sciences ,Probability ,Pollutant ,Inhalation exposure ,021110 strategic, defence & security studies ,Air Pollutants ,Inhalation Exposure ,Health risk assessment ,Public Health, Environmental and Occupational Health ,Southern chinese ,General Medicine ,Pollution ,Monitoring program ,Environmental chemistry ,Environmental science ,Monte Carlo Method ,Cancer slope factor ,Environmental Monitoring - Abstract
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in atmosphere, which attracted more attentions due to their influence on human health. In this study, a national scale cancer risk (CR) assessment with atmospheric PAHs were conducted based on one year monitoring program at 11 cities across China. The annual mean concentrations of benzo[a]pyrene (BaP) and BaP equivalency (BaPeq) were 4.56 ± 7.78 ng/m3 and 8.45 ± 14.1 ng/m3, respectively, which were both higher than the new ambient air quality standards of China (GB 3095–2012, 1 ng/m3). Concentrations of BaP and BaPeq in northern Chinese cities were almost 2 times higher than those in southern Chinese cities. The CR values induced by the dermal contact exposure were two orders of magnitude higher than that by the inhalation exposure. Children and adults were the most sensitive age groups with the dermal contact exposure and the inhalation exposure to atmospheric PAHs, respectively. For the total CR values, 99.7% of its values were higher than the reference level of 10−6. No significant difference of the total CR values was observed between northern Chinese and southern Chinese cities for children and adults. In order to quantify the uncertainties of CR assessment, Monte Carlo Simulation was applied based on the specific distributions of the exposure factors cited from the Exposure Factors Handbook of Chinese Population. The results indicated that almost 90% probability of the total CR values were higher than 10−6, indicating potential cancer risk. Sensitive analysis indicated that atmospheric concentration, outdoor exposure fraction, particle amount adhered to skin, and cancer slope factor should be carefully considered in order to increase the accuracy of CR assessment with PAHs in atmosphere.
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- 2020
19. Occurrence and partitioning of brominated flame retardants (BFRs) in indoor air and dust: a 15-month case study in a test home
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Yong-Feng Li, Jia-Qi Guo, Zi-Feng Zhang, Wan-Li Ma, Chun-Yan Huo, Li-Yan Liu, Yi-Fan Li, and Yu Sun
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China ,Indoor air ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,01 natural sciences ,law.invention ,Polybrominated diphenyl ethers ,law ,Halogenated Diphenyl Ethers ,Environmental Chemistry ,Fugacity ,Relative humidity ,0105 earth and related environmental sciences ,Flame Retardants ,Dust ,General Medicine ,Pollution ,Mass Percentage ,Ventilation ,Partition coefficient ,Environmental chemistry ,Air Pollution, Indoor ,Brominated flame retardant ,Ventilation (architecture) ,Environmental science ,Environmental Monitoring - Abstract
Ten polybrominated diphenyl ethers (PBDEs) and 16 novel brominated flame retardants (NBFRs) were measured in air and dust samples collected in a test home in Harbin, China, from January 2017 to June 2018. The PBDE and NBFR concentrations in indoor air were in the ranges of 0.598–14.5 pg m−3 and 9.28–686 pg m−3, respectively. The ranges of the PBDE and NBFR concentrations in indoor dust were 221–1060 ng g−1 and 71.9–1160 ng g−1, respectively. Brominated flame retardant (BFR) concentrations in indoor air were affected by the temperature, relative humidity (RH), and ventilation. The BFR concentrations in indoor dust did not show temperature dependence. All dust samples were sieved into 6 size fractions (F1–F6: 1000–2000 μm, 500–1000 μm, 250–500 μm, 125–250 μm, 63–125 μm, and
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- 2019
20. Indoor occurrence and health risk of formaldehyde, toluene, xylene and total volatile organic compounds derived from an extensive monitoring campaign in Harbin, a megacity of China
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Li-Yan Liu, Wei Sun, Zi-Feng Zhang, Xianming Zhang, Yi-Fan Li, and Xue Zhang
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China ,Environmental Engineering ,Threshold limit value ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Population ,Formaldehyde ,02 engineering and technology ,010501 environmental sciences ,Xylenes ,01 natural sciences ,Risk Assessment ,chemistry.chemical_compound ,Indoor air quality ,Environmental Chemistry ,Humans ,Relative humidity ,education ,0105 earth and related environmental sciences ,Pollutant ,education.field_of_study ,Air Pollutants ,Volatile Organic Compounds ,Xylene ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Toluene ,020801 environmental engineering ,chemistry ,Environmental chemistry ,Air Pollution, Indoor ,Environmental science ,Environmental Monitoring - Abstract
Human exposure to formaldehyde, toluene, xylene (FTX) and other volatile organic compounds (VOCs) are associated with negative health impact. To characterize the exposure and health effects of FTX and TVOC from indoor environments, we conducted an extensive monitoring campaign involving 1278 measurements of 472 indoor locations in Harbin, a megacity in China from May 2013 to March 2018. The results showed that household had the highest mean formaldehyde concentration (0.171 ± 0.084 mg m-3) among all types of indoor environments. Meanwhile, there was no significant differences in formaldehyde concentration of the living room, master bedroom, secondary bedroom and study room (p > 0.05), as well as toluene and xylene. The highest mean concentration of toluene, xylene and TVOC was measured in public bath center. Great difference was found between formaldehyde concentrations in 2013 and other years, except 2015. There were great positive nonlinear correlations between the indoor temperature and concentration of formaldehyde (p
- Published
- 2019
21. Fate and Occurrence of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Water and Sediment from Songhua River, Northeast China
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Li-Yan Liu, Wei-Wei Song, Chao Jiang, Anatoly N. Nikolaev, Ying-Hua Hu, Rashid Mohammed, Wan-Li Ma, Zi-Feng Zhang, and Yi-Fan Li
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Pollutant ,Water supply for domestic and industrial purposes ,010504 meteorology & atmospheric sciences ,seasonal variations ,Geography, Planning and Development ,risk assessment ,Sediment ,Fraction (chemistry) ,Hydraulic engineering ,010501 environmental sciences ,Aquatic Science ,01 natural sciences ,Biochemistry ,River water ,PAHs ,water–sediment exchange ,Dry weight ,Environmental chemistry ,Environmental science ,Fugacity ,TC1-978 ,TD201-500 ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
The Songhua River is one of the most populated and oldest industrial areas in Northeast China. To understand the sources and distribution of polycyclic aromatic hydrocarbons and their derivatives, such as 16 priority (PAHs), 33 methylated (Me-PAHs), and 12 nitrated (NPAHs) in river water and sediment, were noticed. The concentrations of ∑PAHs, ∑Me-PAHs, and ∑NPAHs in river water scaled from 135 to 563, 9.36 to 711, and 1.26 to 64.7 ng L−1, with mean values of 286, 310, and 17.9 ng L−1, and those in sediments were from 35.8 to 2000 ng g−1, 0.62 to 394 ng g−1, and 0.28 to 176 ng g−1 (dry weight) with mean values of 283, 103, and 21.7 ng g−1. The compositions proved that two-ring and three-ring compounds of PAHs, NPAHs, and four-ring, six-ring of Me-PAHs were prevalent in water samples, in contrast, four-ring dominated in sediments. Principal components analysis (PCA) and diagnostic ratios confirmed that pollutant source was mixed petrogenic and pyrogenic origin. The fugacity fraction (ƒƒ) was also calculated to explain the trend of sediment–water exchange, high ƒƒ values found in summer, for most HMW PAHs and Me-PAHs that these substances acted as a secondary source of emissions from sediment to water. The risk assessment for water was categorized as high.
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- 2021
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22. Occurrence, Removal, and Mass Balance of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Wastewater Treatment Plants in Northeast China
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Roland Kallenborn, Ying-Hua Hu, Yi-Fan Li, Chao Jiang, Li-Yan Liu, Wei-Wei Song, Rashid Mohammed, Anatoly N. Nikolaev, Wan-Li Ma, and Zi-Feng Zhang
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010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,ecological risk assessment ,model prediction ,Biomass ,010501 environmental sciences ,lcsh:Chemical technology ,Toxicology ,01 natural sciences ,Article ,chemistry.chemical_compound ,PAHs ,lcsh:TP1-1185 ,Coal ,Effluent ,wastewater treatment plant ,0105 earth and related environmental sciences ,Anthracene ,Chemical Health and Safety ,business.industry ,Potential risk ,chemistry ,Environmental chemistry ,Pyrene ,Composition (visual arts) ,Sewage treatment ,business - Abstract
Polycyclic aromatic hydrocarbons (PAHs), 33 methylated PAHs (Me-PAHs), and 14 nitrated PAHs (NPAHs) were measured in wastewater treatment plants (WWTPs) to study the removal efficiency of these compounds through the WWTPs, as well as their source appointment and potential risk in the effluent. The concentrations of ∑PAHs, ∑Me-PAHs, and ∑NPAHs were 2.01–8.91, 23.0–102, and 6.21–171 µg/L in the influent, and 0.17–1.37, 0.06–0.41 and 0.01–2.41 µg/L in the effluent, respectively. Simple Treat 4.0 and meta-regression methods were applied to calculate the removal efficiencies (REs) for the 63 PAHs and their derivatives in 10 WWTPs and the results were compared with the monitoring data. Overall, the ranges of REs were 55.3–95.4% predicated by the Simple Treat and 47.5–97.7% by the meta-regression. The results by diagnostic ratios and principal component analysis PCA showed that “mixed source” biomass, coal composition, and petroleum could be recognized to either petrogenic or pyrogenic sources. The risk assessment of the effluent was also evaluated, indicating that seven carcinogenic PAHs, Benzo[a]pyrene, Dibenz[a,h]anthracene, and Benzo(a)anthracene were major contributors to the toxics equivalency concentrations (TEQs) in the effluent of WWTPs, to which attention should be paid.
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- 2021
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23. Relative developmental toxicity of short-chain chlorinated paraffins in Zebrafish (Danio rerio) embryos
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Li-Yan Liu, Wan-Li Ma, Li-Hua Liu, Yi-Fan Li, Hing Man Chan, and Mehmet Coelhan
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Hypothalamo-Hypophyseal System ,Thyroid Hormones ,medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,Thyroid Gland ,0211 other engineering and technologies ,Danio ,Developmental toxicity ,Gene Expression ,DIO2 ,02 engineering and technology ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Chlorinated paraffins ,Internal medicine ,Hydrocarbons, Chlorinated ,medicine ,Animals ,Humans ,Zebrafish ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,Triiodothyronine ,biology ,Thyroid ,General Medicine ,biology.organism_classification ,Pollution ,Endocrinology ,medicine.anatomical_structure ,Paraffin ,Toxicity ,Environmental Pollutants ,Chlorine ,Environmental Monitoring ,Hormone - Abstract
Short-chain chlorinated paraffins (SCCPs) are ubiquitous in the environment and might cause adverse environmental and human health effects. Little is known about the relative toxicity of different SCCP compounds especially during development. The objective of this study was to characterize and compare effects of seven SCCP groups at environmentally relevant levels, using a zebrafish (Danio rerio) model. Observations on malformation, survival rates at 96 h post fertilization (hpf), and hatching rates at 72 hpf indicated that the C10- groups (C10H18Cl4, 1,2,5,6,9,10-C10H16Cl6 and C10H15Cl7) were more toxic than the C12- groups (C12H22Cl4, C12H19Cl7 and 1,1,1,3,10,12,12,12-C12H18Cl8) and Cereclor 63L. The C10- groups were also more potent than C12- groups and Cereclor 63L in decreasing thyroid hormone levels. Among the three compounds within the C10- group, the compounds with less chlorine content had stronger effects on sub-lethal malformations but less effects on triiodothyronine (T3) and tetraiodothyronine (T4). Only C10H18Cl4 significantly decreased the mRNA expression of tyr, ttr, dio2 and dio3 at a dose-dependent manner suggesting that the specific mode of actions differ with different congeners. The mechanisms of disruption of thyroid status by different SCCPs could be different. C10H18Cl4 might inhibit T3 production through the inhibition effect on dio2. These results indicate that SCCP exposure could alter gene expression in the hypothalamic-pituitary-thyroid (HPT) axis and thyroid hormone levels. The mechanisms of disruption of thyroid status by different SCCPs could be different. Our results on the relative developmental toxicities of SCCPs will be useful to reach a better understanding of SCCP toxicity supporting environmental risk evaluation and regulation and used as a guidance for environmental monitoring of SCCPs in the future.
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- 2016
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24. Multi-year air monitoring of legacy and current-use brominated flame retardants in an urban center in northeastern China
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Wei-Wei Song, Zi-Feng Zhang, Wen-Long Li, Li-Na Qiao, Yi-Fan Li, Wan-Li Ma, Li-Yan Liu, and Chun-Yan Huo
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Air Pollutants ,China ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Chemistry ,010501 environmental sciences ,01 natural sciences ,Pollution ,Atmosphere ,Air monitoring ,Polybrominated diphenyl ethers ,Air pollutants ,Environmental chemistry ,Halogenated Diphenyl Ethers ,Environmental Chemistry ,Relative humidity ,Cities ,Waste Management and Disposal ,Environmental Monitoring ,Flame Retardants ,0105 earth and related environmental sciences - Abstract
The occurrence and temporal trends of polybrominated diphenyl ethers (PBDEs) and non-PBDE brominated flame retardants (NBFRs) were investigated in an urban atmosphere of Northeast China in consecutive six years (2008-2013). Among all chemicals, BDE-209, l,2,5,6,9,10-hexabromocyclododecane (HBCD), and decabromodiphenylethane (DBDPE) were the three most dominant compounds. During the period, the levels of pentabromodiphenyl ethers in the gas-phase and octabromodiphenyl ethers in the particle-phase significantly decreased, while the levels of BDE-209 and NBFRs increased in either the gas-phase or particle-phase. Ambient temperature was the most significant variable that influenced the gas-phase and particle-phase concentrations of BFRs, followed by wind speed and relative humidity. A stronger temperature dependence of the atmospheric concentrations was found for lower mass BFRs. Gas-particle partitioning studies suggested PBDEs in the urban atmosphere of Northeast China were at steady-state. Steady-state equation can also well describe the partitioning behavior for NBFRs, suggesting that the atmospheric partitioning behaviors of NBFRs were similar to those of PBDEs.
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- 2016
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25. Research on persistent organic pollutants in China on a national scale: 10 years after the enforcement of the Stockholm Convention
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Wan-Li Ma, Yi-Fan Li, Hongliang Jia, Zi-Feng Zhang, Wei-Wei Song, and Li-Yan Liu
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China ,Time Factors ,010504 meteorology & atmospheric sciences ,International Cooperation ,Health, Toxicology and Mutagenesis ,Developing country ,Distribution (economics) ,Environmental pollution ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Environmental protection ,Political science ,Soil Pollutants ,Emission inventory ,Enforcement ,Environmental planning ,0105 earth and related environmental sciences ,Air Pollutants ,Government ,business.industry ,Research ,General Medicine ,Pollution ,Monitoring program ,Environmental Pollution ,business - Abstract
As a signatory of the Stockholm Convention and the largest developing country, China plays a very important role in implementation of the convention to reduce and finally eliminate persistent organic pollutants (POPs) in the world. In the past ten years after the enforcement in 2004, Chinese Government and scientists have made great progress on the study of POPs. The present work aims to provide an overview on recent studies on POPs in China, with particular focus on usage/emission inventory, residue inventory, and pollution status of POPs on national scale. Several legend (old) and new target POPs were comprehensively summarized with progress on inventory. Furthermore, several national scale monitoring programs have been selected for the occurrence, spatial and temporal trends of POPs in China, which are compared with Asian data and Global data. Based on the observed results, some important scientific issues, such as the primary and secondary distribution patterns, the primary and secondary fractionations, and air-soil exchange of POPs, are also discussed. It is proposed that more studies should be carried out for the new targeted POPs in future for both the national and global interests.
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- 2016
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26. Phthalates in dormitory and house dust of northern Chinese cities: Occurrence, human exposure, and risk assessment
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Wei-Wei Song, Jia Li, Chong-Jing Gao, Mohammed O.A. Mohammed, Wan-Li Ma, Zi-Feng Zhang, Kurunthachalam Kannan, Yi-Fan Li, Li-Yan Liu, Hai-Ling Li, and Chun-Yan Huo
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Male ,China ,endocrine system ,Environmental Engineering ,Adolescent ,Universities ,010504 meteorology & atmospheric sciences ,Dibutyl phthalate ,Phthalic Acids ,010501 environmental sciences ,Risk Assessment ,01 natural sciences ,Young Adult ,chemistry.chemical_compound ,Environmental health ,Humans ,Environmental Chemistry ,Significant risk ,Cities ,Health risk ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Phthalate ,Dust ,Environmental Exposure ,Environmental exposure ,Hazard index ,Pollution ,chemistry ,Human exposure ,Environmental science ,Female ,Risk assessment - Abstract
Phthalates are widely used chemicals in household products, which severely affect human health. However, there were limited studies emphasized on young adults' exposure to phthalates in dormitories. In this study, seven phthalates were extracted from indoor dust that collected in university dormitories in Harbin, Shenyang, and Baoding, in the north of China. Dust samples were also collected in houses in Harbin for comparison. The total concentrations of phthalates in dormitory dust in Harbin and Shenyang samples were significantly higher than those in Baoding samples. The total geometric mean concentration of phthalates in dormitory dust in Harbin was lower than in house dust. Di-(2-ethylhexyl) phthalate (DEHP) was the most abundant phthalate in both dormitory and house dust. The daily intakes of the total phthalates, carcinogenic risk (CR) of DEHP, hazard index (HI) of di-isobutyl phthalate (DiBP), dibutyl phthalate (DBP), and DEHP were estimated, the median values for all students in dormitories were lower than adults who live in the houses. Monte Carlo simulation was applied to predict the human exposure risk of phthalates. HI of DiBP, DBP, and DEHP was predicted according to the reference doses (RfD) provided by the United States Environmental Protection Agency (U.S.EPA) and the reference doses for anti-androgenicity (RfD AA) developed by Kortenkamp and Faust. The results indicated that the risks of some students had exceeded the limitation, however, the measured results were not exceeded the limitation. Risk quotients (RQ) of DEHP were predicted based on China specific No Significant Risk Level (NSRL) and Maximum Allowable Dose Level (MADL). The predicted results of CR and RQ of DEHP suggested that DEHP could pose a health risk through intake of indoor dust.
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- 2016
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27. Distribution patterns and characterization of outdoor fine and coarse particles
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Mohammed O.A. Mohammed, Yi-Fan Li, Li yan Liu, Mei yun Qi, Mohammed A.E.M. Ibrahim, Wan-Li Ma, Feng yan Wang, Na Lv, Ahmed A. Elzaki, and Wei wei Song
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Pollution ,Total organic carbon ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,Analytical chemistry ,PM2.5 ,010501 environmental sciences ,Atmospheric sciences ,Discriminant analysis ,01 natural sciences ,Hierarchical clustering ,Severe cold ,Wind speed ,Early winter ,PM10 ,Positive matrix factorization ,Environmental science ,Receptor model ,Relative humidity ,Waste Management and Disposal ,0105 earth and related environmental sciences ,media_common - Abstract
Simultaneous measurements of fine (PM 2.5 ) and coarse (PM 10 ) particles have been performed during three sampling period: summertime, early winter before the heating period, and during the winter heating. The sampling was done at an urban site, Harbin City, China, to apportion pollution sources and to investigate the impacts of weather parameters and emission sources on distribution patterns of PM 2.5 and PM 10 and their chemical compositions. Two chemometric techniques, hierarchical clustering analysis (HCA) and discriminant analysis (DA), and a receptor model (PMF5) were applied. The average mass concentrations of fine and coarse particles during the whole study period (i.e. annual averages), were 82.4 μg/m 3 and 120.1 μg/m 3 , with relative humidity and wind speed being the main factors influencing distribution patterns of PM 2.5 and PM 10, while sum of major ions ( NO 3 − , NH 4 + , SO 4 2 − ), and organic carbon (OC) were the greater contributor to total mass concentrations. According to DA, the distribution patterns of PM 2.5 and PM 10 during the winter heating period were distinct but overlapping in summer and early winter before heating, implying that, PM 2.5 and PM 10 were originated from different sources during the winter heating period but from similar sources during the other two sampling periods. This claim was further supported by PMF results. Canonical discriminant function coefficients of DA have shown species such as OC, EC, SO 4 2 − , NO 3 − , Cl − , Ti, Sr, Ca 2+ , Ni, and Ba to be good predictors/discriminants responsible for the differences between the three sampling periods. HCA visualized the interrelations among the source markers, while the PMF5 modeling confirmed HCA findings.
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- 2016
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28. Distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air in cold zone
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Na Lv, Mohammed O.A. Mohammed, Wei-Wei Song, Yongliang Ma, Mei-yun Qi, Wen-Long Li, Afed Ulla Khan, Ding-zhen Wang, Li-Yan Liu, Feng-yan Wang, Yi-Fan Li, and Wan-Li Ma
- Subjects
Chrysene ,China ,Crop residue ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Coal combustion products ,010501 environmental sciences ,Atmospheric sciences ,Risk Assessment ,01 natural sciences ,chemistry.chemical_compound ,Humans ,Environmental Chemistry ,Relative humidity ,Cities ,Particle Size ,Polycyclic Aromatic Hydrocarbons ,0105 earth and related environmental sciences ,Air Pollutants ,Retene ,Health risk assessment ,Public Health, Environmental and Occupational Health ,Environmental engineering ,General Medicine ,General Chemistry ,Particulates ,Infiltration (HVAC) ,Pollution ,Cold Temperature ,chemistry ,Air Pollution, Indoor ,Environmental science ,Particulate Matter ,Environmental Monitoring - Abstract
In this study we investigated the distribution patterns, infiltration and health risk assessment of PM2.5-bound PAHs in indoor and outdoor air done in Harbin city, northeastern China. Simultaneous indoor and outdoor sampling was done to collect 264 PM2.5 samples from four sites during winter, summer, and spring. Infiltration of PAHs into indoors was estimated using Retene, Benzo [ghi]perylene and Chrysene as reference compounds, where the latter compound was suggested to be a good estimator and subsequently used for further calculation of infiltration factors (IFs). Modeling with positive matrix factorization (PMF5) and estimation of diagnostic isomeric ratios were applied for identifying sources, where coal combustion, crop residues burning and traffic being the major contributors, particularly during winter. Linear discriminant analysis (LDA) has been utilized to show the distribution patterns of individual PAH congeners. LDA showed that, the greatest seasonal variability was attributed to high molecular weight compounds (HMW PAHs). Potential health risk of PAHs exposure was assessed through relative potency factor approach (RPF). The levels of the sum of 16 US EPA priority PAHs during colder months were very high, with average values of 377 ± 228 ng m(-)(3) and 102 ± 75.8 ng m(-)(3), for the outdoors and indoors, respectively. The outdoor levels reported to be 19 times higher than the outdoor concentrations during warmer months (summer + spring), while the indoor concentrations were suggested to be 9 times and 10 times higher than that for indoor summer (average 11.73 ± 4 ng m(-3)) and indoor spring (9.5 ± 3.3 ng m(-3)). During nighttime, outdoor PAHs revealed wider range of values compared to datytime which was likely due to outdoor temperature, a weather parameter with the strongest negative influence on ∑16PAHs compared to low impact of relative humidity and wind speed.
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- 2016
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29. Phthalate Esters in Indoor Window Films in a Northeastern Chinese Urban Center: Film Growth and Implications for Human Exposure
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Zhi-Xiang Peng, Yong-Kai Wu, Ya-Meng Han, Chun-Yan Huo, Yi-Fan Li, Wan-Li Ma, Kurunthachalam Kannan, Li-Yan Liu, Wei-Wei Song, Hai-Ling Li, Zi-Feng Zhang, and Wen-Long Li
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China ,Inhalation Exposure ,010504 meteorology & atmospheric sciences ,Dibutyl phthalate ,Phthalic Acids ,Environmental engineering ,Phthalate ,Esters ,General Chemistry ,Diisobutyl phthalate ,010501 environmental sciences ,01 natural sciences ,Dibutyl Phthalate ,chemistry.chemical_compound ,Phthalic acid ,Animal science ,chemistry ,Human exposure ,Cold winter ,Humans ,Environmental Chemistry ,Relative humidity ,Seasons ,0105 earth and related environmental sciences - Abstract
Indoor window film samples were collected in buildings during 2014-2015 for the determination of six phthalate diesters (PAEs). Linear regression analysis suggested that the film mass was positively and significantly correlated with the duration of film growth (from 7 to 77 days). PAEs were detected in all window film samples (n = 64). For all the samples with growth days ranged from 7 to 77 days, the median concentrations of total six PAEs (∑6PAEs) in winter and summer window film samples were 9900 ng/m(2) film (2000 μg/g film) and 4700 ng/m(2) film (650 μg/g film), respectively. Among PAEs analyzed, di-2-ethyl-hexyl phthalate (DEHP) was the major compound (71 ± 9.7%), followed by di-n-butyl phthalate (DBP; 20 ± 7.4%) and diisobutyl phthalate (DiBP; 5.1 ± 2.2%). Positive correlations among PAEs suggested their common sources in the window film samples. Room temperature and relative humidity were negatively and significantly correlated with PAEs concentations (in ng/m(2)). Poor ventilation in cold winter in Noreastern China significantly influenced the concentrations of PAEs in window film which suggested higher inhalation exposure dose in winter. The median hazard quotient (HQ) values from PAEs exposure were below 1, suggesting that the intake of PAEs via three exposure pathways was considered as acceptable.
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- 2016
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30. The occurrence and fate of siloxanes in wastewater treatment plant in Harbin, China
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Shaojing Sun, Bo Li, Li-Yan Liu, Ning-Zheng Zhu, Hong Qi, Wen-Long Li, Yi-Fan Li, Wan-Li Ma, and Zi-Feng Zhang
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China ,Siloxanes ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Sewage ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Soil ,chemistry.chemical_compound ,Rivers ,medicine ,Environmental Chemistry ,Ecotoxicology ,Effluent ,0105 earth and related environmental sciences ,Air Pollutants ,business.industry ,General Medicine ,Seasonality ,medicine.disease ,Pollution ,chemistry ,Environmental chemistry ,Siloxane ,Environmental science ,Sewage treatment ,Adsorption ,Seasons ,business ,Water Pollutants, Chemical ,Sludge - Abstract
The occurrence and fate of four cyclic (D3 to D6) and 10 linear (L5 to L14) siloxanes were investigated in influent and effluent wastewater, sludge from a wastewater treatment plant (WWTP), and surrounding air and soil within the WWTP in Harbin, Northeast China. The mean concentrations of total siloxanes in influent and effluent were 4780 and 997 ng/L and in excess sludge and aerobic sludge were 25.1 and 32.3 μg/g dw, respectively. The concentrations in air and soil within the WWTP were 243 ng/m(3) and 4960 ng/g dw, respectively. A similar composition profile of siloxanes in influent and sludge suggests their same source. Seasonal variation with concentration was comprehensively studied. It was found that temperature and rainfall are the two important factors for the seasonal variation of siloxanes. Adsorption with sewage sludge was the major way for the removal of siloxanes during the municipal wastewater treatment process. Overall, on a daily basis, the mass loading of the Σsiloxanes into the WWTP, out of the WWTP with the effluent and sludge, were estimated to be 3.0, 0.6 and 1.3 kg, respectively. In general, 21 % of siloxanes were discharged into the receiving body (Songhua River), 43 % of siloxanes were absorbed on sludge, and 36 % of siloxanes were lost during the whole process of WWTP.
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- 2016
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31. Phthalate metabolites in urine of Chinese young adults: Concentration, profile, exposure and cumulative risk assessment
- Author
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Nanqi Ren, Li-Yan Liu, Wan-Li Ma, Chong-Jing Gao, Ning-Zheng Zhu, Ying Guo, Ling Jiang, Kurunthachalam Kannan, and Yi-Fan Li
- Subjects
Adult ,0301 basic medicine ,China ,Environmental Engineering ,Urinary system ,Phthalic Acids ,Urine ,010501 environmental sciences ,Risk Assessment ,01 natural sciences ,Toxicology ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,Humans ,Environmental Chemistry ,Food science ,Young adult ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Phthalate ,Environmental Exposure ,Environmental exposure ,Pollution ,Hazard quotient ,030104 developmental biology ,chemistry ,Human exposure ,Environmental Pollutants ,Cumulative risk assessment - Abstract
Phthalates are widely used in consumer products. People are frequently exposed to phthalates due to their applications in daily life. In this study, 14 phthalate metabolites were analyzed in 108 urine samples collected from Chinese young adults using high-performance liquid chromatography-tandem mass spectrometry. The total concentrations of 14 phthalate metabolites ranged from 71.3 to 2670 ng/mL, with the geometric mean concentration of 306 ng/mL. mBP and miBP were the two most abundant compounds, accounting for 48% of the total concentrations. Principal component analysis suggested two major sources of phthalates: one dominated by the DEHP metabolites and one by the group of mCPP, mBP and miBP metabolites. The estimated daily intakes of DMP, DEP, DBP, DiBP and DEHP were 1.68, 2.14, 4.12, 3.52 and 1.26-2.98 μg/kg-bw/day, respectively. In a sensitivity analysis, urinary concentration and body weight were the most influential variables for human exposure estimation. Furthermore, cumulative risk for hazard quotient (HQ) and hazard index (HI) were evaluated. Nearly half of Chinese young adults had high HI values exceeding the safe threshold. This is the first study on the occurrence and human exposure to urinary phthalate metabolites with Chinese young adults.
- Published
- 2016
- Full Text
- View/download PDF
32. Substituted diphenylamine antioxidants (SDPAs) in typical domestic wastewater treatment plants and Songhua River in the northeast of China
- Author
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Wan-Li Ma, Bo Meng, Li-Yan Liu, Xue Zhang, Yi-Fan Li, Ming-yu Sun, Wen-Long Li, Wei-Wei Song, and Zi-Feng Zhang
- Subjects
China ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Occurrence data ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Antioxidants ,Water Purification ,chemistry.chemical_compound ,Rivers ,medicine ,Environmental Chemistry ,Effluent ,0105 earth and related environmental sciences ,Diphenylamine ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Seasonality ,medicine.disease ,Pollution ,020801 environmental engineering ,chemistry ,Environmental chemistry ,Environmental science ,Sewage treatment ,Seasons ,Surface water ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Limited studies focus on the occurrence, removal rate and seasonal variation of substituted diphenylamine antioxidants (SDPAs) in surface water and wastewater in China. In this paper, the detection method of SDPAs was established by the ultra-performance liquid chromatography-tandem mass spectrometry. Daily variations suggested that significant variations were found for the concentrations of some SDPAs in the influent. It was found that the SDPAs could be detected in all the effluent samples and C8/C8-DPA was the predominant compound in two WWTPs. The levels of most SDPAs in the effluent were much lower than that of influent, with the removal efficiencies of total SDPAs ranged from 57.9% to 84.2%. There were significant differences with the SDPA concentrations in the influent between different seasons. Higher concentrations of SDPAs were found at downstream than those of upstream. The results of this study provide more environmental occurrence data and new insights into the research on the environmental fate of these compounds.
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- 2020
- Full Text
- View/download PDF
33. Seasonal variation and influence factors of organophosphate esters in air particulate matter of a northeastern Chinese test home
- Author
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Chun-Yan Huo, Yu Sun, Li-Yan Liu, Wan-Li Ma, Wei-Wei Song, Jia-Qi Guo, Li Wang, Ed Sverko, Zhi Zhang, Yi-Fan Li, Zi-Feng Zhang, Hai-Ling Li, and Chongguo Tian
- Subjects
China ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Organophosphate ,Suspended particles ,Esters ,010501 environmental sciences ,Particulates ,Seasonality ,medicine.disease ,01 natural sciences ,Pollution ,Organophosphates ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,medicine ,Environmental Chemistry ,Environmental science ,Particulate Matter ,Seasons ,Waste Management and Disposal ,Environmental Monitoring ,Flame Retardants ,0105 earth and related environmental sciences - Abstract
To investigate the seasonal variation of organophosphate esters (OPEs) in air particulate matter (PM) and the corresponding influence factors in indoor environment, 104 indoor PM samples were collected in a test home, Harbin, China, from March 2017 to March 2018. The Σ12OPEs concentrations ranged from 0.41 ng/m3 to 940 ng/m3. Tris(1-chloro-2-propyl) phosphate (TCIPP) was the most abundant OPE and accounted for 83.2% of the total OPEs. The Σ12OPEs concentrations in spring and summer were higher than those in autumn and winter. Outdoor total suspended particles (TSP) were the main factor that affected the concentration variation of OPEs in PM samples in the test home. Comparisons of the gas/particle (G/P) partitioning equilibrium models indicated that the Dachs-Eisenreich (D-E) model estimates were more reliable than the other models in this study. The particle fractions of OPEs with log KOA > 10.51 that predicted by all four models generally well matched the measured OPE particle fractions in the literatures. To OPEs with lower molecular weight, inhalation was the main exposure route and ingestion contributed mostly to OPEs with higher molecular weight. In addition, the estimated daily intakes (EDIs) and carcinogenic risks (CRs) posed by OPEs were all below the recommended values, indicating that the current OPE levels in the test home were within the safe thresholds.
- Published
- 2020
- Full Text
- View/download PDF
34. Semi-volatile organic compounds in infant homes: Levels, influence factors, partitioning, and implications for human exposure
- Author
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Wei-Wei Song, Li-Yan Liu, Hai-Ling Li, Zi-Feng Zhang, Wan-Li Ma, Zhi Zhang, Ed Sverko, Yi-Fan Li, and Yu Sun
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China ,010504 meteorology & atmospheric sciences ,Smoking habit ,Health, Toxicology and Mutagenesis ,Living environment ,Phthalic Acids ,Infant health ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Polybrominated diphenyl ethers ,Halogenated Diphenyl Ethers ,Ingestion ,Humans ,Polycyclic Aromatic Hydrocarbons ,0105 earth and related environmental sciences ,Inhalation Exposure ,Volatile Organic Compounds ,Infant exposure ,Infant ,Dust ,General Medicine ,Pollution ,Organophosphates ,Human exposure ,Environmental chemistry ,Air Pollution, Indoor ,Housing ,Environmental science ,Detection rate - Abstract
While infants are developing, they are easily affected by toxic chemicals existing in their environments, such as semi-volatile organic compounds (SVOCs): phthalates, polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and organophosphate esters (OPEs). However, the specific living environment of infants, including increased plastic products and foam floor mats, may increase the presence of these chemicals. In this study, 68 air, dust, and window film samples were collected from homes, with 3- to 6-month-old infant occupants, to analyze phthalates, PAHs, PBDEs, and OPEs. High detection rates and concentrations suggest that these SVOCs are widespread in infant environments and are associated with cooking methods, smoking habits, the period of time after decoration, and room floors. The partitioning behavior of SVOCs indicates that the logarithms of the dust/gas-phase air partition coefficient (logKD) and the window film/gas-phase air partition coefficient (logKF) in homes are not at an equilibrium state when the logarithm of the octanol/air partition coefficient (logKOA) is less than 8 or greater than 11. Considering the 3 exposure routes, ingestion and dermal absorption have become the main routes of infant exposure to phthalates and OPEs, and ingestion and inhalation have become the dominant routes of exposure to PAHs and PBDEs. The total carcinogenic risk of SVOCs, which have carcinogenic toxicities, via ingestion and dermal absorption for infants in homes exceeds the acceptable value, suggesting that the current levels of these SVOCs in homes might pose a risk to infant health.
- Published
- 2019
35. Assessment of human indoor exposure to PAHs during the heating and non-heating season: Role of window films as passive air samplers
- Author
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Wan-Li Ma, Zi-Feng Zhang, Wei-Wei Song, Yu Sun, Wen-Long Li, Li-Yan Liu, Chun-Yan Huo, Ed Sverko, and Yi-Fan Li
- Subjects
Pollutant ,Air Pollutants ,China ,Inhalation Exposure ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Heating season ,Window (geology) ,010501 environmental sciences ,01 natural sciences ,Pollution ,Partition coefficient ,Organic film ,Heating ,Environmental chemistry ,Air Pollution, Indoor ,Environmental Chemistry ,Environmental science ,Humans ,Stage (hydrology) ,Seasons ,Polycyclic Aromatic Hydrocarbons ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Environmental Monitoring - Abstract
The study of indoor organic film on planar surfaces has been shown to be important to assess the transport and fate of organic pollutants in indoor environments. Limited research showed the relationship between equilibrium status of polycyclic aromatic hydrocarbons (PAHs) and the growth days for indoor window films. To accomplish this goal, indoor window film samples were collected in relation to film growth days in Northeast China. PAHs were frequently detected in window films collected during heating season (H-season), with concentrations significantly higher than that of non-heating season (NH-season). Accumulation characteristics of PAH suggested that PAH concentrations (ng/m2 film) were growing near-linearly with time. Partitioning status for PAHs between gas and window films under different accumulation stage from 1 to 11 weeks was investigated during the two seasons. The equilibrium status of PAHs in the films suggested that the octanol–air partition coefficient (logKOA) of the targeted PAHs should be approximately
- Published
- 2018
36. A Stock Trading Intention Recognition Model Based on Data Clustering
- Author
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Sheng-lin Cao, Xue-mei Ma, Feng Yu, and Li-yan Liu
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Computer science ,Feature extraction ,Feature selection ,010103 numerical & computational mathematics ,02 engineering and technology ,computer.software_genre ,01 natural sciences ,Data modeling ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Pattern matching ,Data mining ,0101 mathematics ,Cluster analysis ,computer ,Database transaction ,Transaction data ,Stock (geology) - Abstract
In practice, many physics principles have been employed to derive various models of stock transaction behavior analysis. However, few studies have been done on the stock trading intention recognition based on feature selection and match on time series stock transaction data. The purpose of this paper is to show how to discover the real stock trading intention by analyzing historical transaction data. Therefore, the proposed recognition model utilizes data clustering with feature selection, trace constructing and pattern matching together to fulfill intention mining and recognizing. The experiment results show the better performance.
- Published
- 2018
- Full Text
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37. Theoretical insights into excited-state intramolecular and multiple intermolecular hydrogen bonds in 2-(2-Hydroxy-phenyl)-4(3H)-quinazolinone
- Author
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Jie Yu, Shuai-Shuai Wu, Shu-Lin Cong, Shuo Chai, and Li-Yan Liu
- Subjects
Chemistry ,Hydrogen bond ,Intermolecular force ,02 engineering and technology ,Time-dependent density functional theory ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Internal conversion (chemistry) ,Photochemistry ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Analytical Chemistry ,Excited state ,Intramolecular force ,Density functional theory ,0210 nano-technology ,Ground state ,Instrumentation ,Spectroscopy - Abstract
The photophysical properties and photochemistry reactions of 2-(2-Hydroxy-phenyl)-4(3H)-quinazolinone (HPQ) system in different solutions are studied by using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. Our theoretical investigation explores that an ultrafast barrier-free excited state intramolecular proton transfer (ESIPT) process occurs and the configuration twisting is found in the electronic excited state. In the polar protic methanol solution, the hydrogen-bonded complex composed by HPQ and two methanol molecules (HPQ-2M) could exist stably in the ground state. Upon photoexcitation the isolated HPQ is initially excited to the first excited state, while the HPQ-2M system is firstly excited to the S3 state and undergoes internal conversion (IC) to the S1 state. The intermolecular hydrogen bonds are strengthened in the excited state. The simulated electronic spectra agree well with the experimental results. The strengthening of the intermolecular hydrogen bonds is also confirmed by the calculated vibrational spectra. In addition, the intramolecular charge transfer happens in both HPQ and HPQ-2M systems from the frontier molecular orbital analysis.
- Published
- 2018
38. An evaluation on the intra-day dynamics, seasonal variations and removal of selected pharmaceuticals and personal care products from urban wastewater treatment plants
- Author
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Wei-Wei Song, Wen-Long Li, Yi-Fan Li, Zi-Feng Zhang, Li-Yan Liu, and Wan-Li Ma
- Subjects
Environmental Engineering ,Intra day ,010504 meteorology & atmospheric sciences ,Population ,Cosmetics ,010501 environmental sciences ,Wastewater ,01 natural sciences ,Environmental impact of pharmaceuticals and personal care products ,Waste Disposal, Fluid ,Industrial wastewater treatment ,Environmental Chemistry ,Humans ,education ,Waste Management and Disposal ,Effluent ,0105 earth and related environmental sciences ,education.field_of_study ,Aquatic ecosystem ,Pollution ,Pharmaceutical Preparations ,Environmental chemistry ,Environmental science ,Sewage treatment ,Seasons ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Pharmaceuticals and personal care products (PPCPs) in wastewater have become an emerging issue due to their negative effects on human health and aquatic ecosystems. Two full-scale municipal and industrial wastewater treatment plants (WWTPs) along the Songhua River were chosen to evaluate the intra-day dynamics, seasonal variations and removal of 12 selected PPCPs. Our results suggested that the selected PPCPs were frequently detected in the influent and effluent. Caffeine was the predominant compound in the influent; while the selected PPCPs was dominated by TCS in the effluent, suggesting the different fates of selected PPCPs in the WWTPs. The intra-day dynamics of PPCPs in the influent were evaluated, suggesting that the 12 PPCPs can be grouped into three categories because of their different use patterns. The analysis of seasonal changes of PPCPs concentrations in the WWTPs suggested that the concentrations of some PPCPs were influenced by the chemical usage, degradation and temperature. The removal efficiency for the PPCPs were very high with the values ranged from 70.0% to 99.7% for WWTP#1, and from 62.5% to 99.4% for WWTP#2. Significant seasonal variations of PPCPs removal efficiency were observed. Base on the mass loading of PPCPs in the two WWTPs, our results suggested that WWTP#1 in the urban core received much more PPCPs in comparison to WWTP#2 in the suburban regions, suggesting that influences of the service population.
- Published
- 2018
39. Five-year trends of selected halogenated flame retardants in the atmosphere of Northeast China
- Author
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Li-Na Qiao, Yi-Fan Li, Wen-Long Li, Wan-Li Ma, Zi-Feng Zhang, Wei-Wei Song, and Li-Yan Liu
- Subjects
China ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Air pollution ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Gas phase ,Atmosphere ,Polybrominated diphenyl ethers ,Air pollutants ,Air Pollution ,Halogenated Diphenyl Ethers ,medicine ,Environmental Chemistry ,Potential source ,Cities ,Waste Management and Disposal ,Flame Retardants ,0105 earth and related environmental sciences ,Air Pollutants ,Contribution function ,Chemistry ,Pollution ,Environmental chemistry - Abstract
This study collected 227 pairs of gas phase and particle phase air samples in a typical urban city of Northeast China from 2008 to 2013. Four alternative halogenated flame retardants for polybrominated diphenyl ethers (PBDEs) were analyzed, namely 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EHTBB), bis (2-ethylhexyl) tetrabromophthalate (BEHTBP), syn-dechlorane plus (syn-DP) and anti-dechlorane plus (anti-DP). The average concentrations for EHTBB and BEHTBP were 5.2 ± 20 and 30 ± 200 pg/m3, respectively, while for syn-DP and anti-DPwere 1.9±5.1 and 5.8±18 pg/m3, respectively. Generally, they were frequently detected in the particle phase, and the gas/particle partitioning suggested they were the maximum partition chemicals. The fractional abundance of EHTBB (fEHTBB) and syn-DP (fsyn)were comparablewith those in other studies. Strong local sources were identified based on the air parcel backward trajectories and the potential source contribution function. The concentrations of these chemicals were significantly increased during this sampling campaign, possibly suggesting their increasing usages from 2008 to 2013 in China.
- Published
- 2016
- Full Text
- View/download PDF
40. Bisphenol A in Urine of Chinese Young Adults: Concentrations and Sources of Exposure
- Author
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Chong-Jing Gao, Yi-Fan Li, Li-Yan Liu, Kurunthachalam Kannan, Ling Jiang, Wan-Li Ma, Nanqi Ren, and Ning-Zheng Zhu
- Subjects
Adult ,Paper ,0301 basic medicine ,China ,endocrine system ,Bisphenol A ,Health, Toxicology and Mutagenesis ,Population ,Physiology ,Food Contamination ,Urine ,Endocrine Disruptors ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,Phenols ,Humans ,Medicine ,Urinary concentration ,Benzhydryl Compounds ,Young adult ,Daily exposure ,education ,0105 earth and related environmental sciences ,Exposure assessment ,education.field_of_study ,urogenital system ,business.industry ,Dietary intake ,Dust ,General Medicine ,Pollution ,Diet ,030104 developmental biology ,chemistry ,business ,hormones, hormone substitutes, and hormone antagonists ,Environmental Monitoring - Abstract
Bisphenol A (BPA) is an endocrine disrupting environmental chemical. Urinary concentrations of BPA were measured in samples collected nationwide from Chinese young adults. The geometric mean urinary concentration of BPA in Chinese young adults was 2.23 ng/mL. The estimated daily exposure dose for BPA was 64.8 ng/kg bw/day. Contributions of various BPA sources to exposure in Chinese young adults were estimated. Dietary intake was the primary exposure pathway. The contribution of dietary intake, indoor dust, paper products and personal care products to BPA intake was 72.5 %, 0.74 %, 0.98 %, 0.22 % of the total exposure dose, respectively. This is the first study on the occurrence of BPA in young adults from most provinces and autonomous regions of China. The results can be used to establish a database for BPA exposure assessment for Chinese general population.
- Published
- 2015
- Full Text
- View/download PDF
41. Removal characteristic of surfactants in typical industrial and domestic wastewater treatment plants in Northeast China
- Author
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Fu-Jie Zhu, Tie-Fu Xu, Wei-Wei Song, Zi-Feng Zhang, Wan-Li Ma, Yi-Fan Li, Xue Zhao, Ding Yi, Wen-Long Li, and Li-Yan Liu
- Subjects
China ,Linear alkylbenzene ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Wastewater ,Treatment unit ,01 natural sciences ,Water Purification ,chemistry.chemical_compound ,Point source pollution ,Surface-Active Agents ,Effluent ,Activated sludge system ,Alkyl ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Sewage ,Chemistry ,Public Health, Environmental and Occupational Health ,General Medicine ,Pulp and paper industry ,Pollution ,Aerobiosis ,020801 environmental engineering ,Alkanesulfonic Acids ,Solubilization ,Sewage treatment ,Seasons ,Water Pollutants, Chemical - Abstract
Surfactants are widely used in household and industrial products for cleaning and/or solubilization in our daily life. Therefore, they are finally discharged into wastewater treatment plants (WWTPs), which may be the major point pollution source for environment if they were not completely removed during wastewater treatment. In this study, two typical industrial and domestic WWTPs with different wastewater treatment technologies were considered for the topic. Totally, two types of surfactants were analyzed in 24 h influent and each processing unit effluent. Four linear alkylbenzene sulfonates (LASs) with the alkyl chain from C10 to C13, and two benzalkonium chlorides (BACs) with the alkyl chain of C12 and C14 were selected as target compounds. The total concentrations of LASs in influent varied from 19.2 to 1889 μg/L and LAS-C11 and LAS-C12 were the predominant compounds with the concentration from 6.01 to 641 μg/L and 8.02–674 μg/L, respectively. The total concentrations of BACs were much lower than those of LASs, with the concentration ranging from 0.00935 to 1.85 μg/L. Significant positive correlations were observed between concentrations of LASs and BACs in influent, indicating their same and/or similar sources. Compared with the concentration of influent, the concentration of effluent was much lower, indicating the high removal efficiency by the two wastewater treatment processes. Biological treatment unit and cyclic activated sludge system were the main treatment units for the removing of surfactants, which suggested that these two types of surfactants can be easily degraded under aerobic condition. Seasonal variation indicated that the removal efficiencies of surfactants in autumn were a little higher than those in winter. The results of this study provided new insights into the environmental fate of surfactants in wastewater treatment system.
- Published
- 2017
42. Modeling the air-soil exchange, secondary emissions and residues in soil of polychlorinated biphenyls in China
- Author
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Qiang Fu, Jianmin Ma, Song Cui, Yi-Fan Li, Li-Yan Liu, Leiming Zhang, and Chongguo Tian
- Subjects
Pollutant ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Science ,Organochlorine pesticide ,Soil carbon ,010501 environmental sciences ,01 natural sciences ,Article ,Vertical transfer ,Environmental chemistry ,Monitoring data ,Secondary emission ,Soil water ,Medicine ,Environmental science ,0105 earth and related environmental sciences - Abstract
The present study investigated the environmental distribution and fate of low molecular weight (LMW) polychlorinated biphenyls (PCBs) in China using the ChnGIPERM (Chinese Gridded Industrial Pollutants Emission and Residue Model), in which the air-soil exchange, spatial-temporal variations and the heterogeneity of secondary emission and residue in the non-source areas were studied. The model simulated the temporal and spatial variations of the PCB28 concentration in soils and air which agreed well with historical monitoring data across China. The long-range atmospheric transport (LRAT) and temperature was identified as the major factor affecting the distribution patterns of the secondary emissions and residues. Soil residue was considered as important environmental fate of PCB28. However, the intensity of an emissions source and the distance with non-source area strongly affected the spatial and temporal variations of PCB28 residues in soil. Several factors strongly impacted the distribution characteristics and air-soil exchange of PCB28, including emission patterns, atmospheric transport, soil organic carbon (SOC), soil vertical transfer, ambient temperature, and precipitation.
- Published
- 2017
- Full Text
- View/download PDF
43. PAHs in Chinese atmosphere: Gas/particle partitioning
- Author
-
Fu-Jie Zhu, Hongliang Jia, Li-Yan Liu, Yi-Fan Li, Meng Yang, and Wan-Li Ma
- Subjects
Environmental Engineering ,Molar mass ,010504 meteorology & atmospheric sciences ,010501 environmental sciences ,Particulates ,01 natural sciences ,Pollution ,Monitoring program ,Gas phase ,Atmosphere ,Orders of magnitude (specific energy) ,Phase (matter) ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,Particle ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
The gas/particle (G/P) partitioning behavior is an important factor for the environmental fate of polycyclic aromatic hydrocarbons (PAHs) in atmosphere. Based on one year monitoring program at 11 urban sites across China, 7647 pairs of gaseous and particulate concentrations were obtained for 16 priority PAHs, which provided a good opportunity to study the G/P partitioning behavior of PAHs. The concentrations of PAHs in both gas and particle phases were not in the same level among the 11 sites with a difference of more than one orders of magnitude. Along with the increase of molar weight of PAHs, the proportion of concentration in particle phase was increasing. In particle phase, the concentrations of ∑16PAHs in northern Chinese cities were significantly (p
- Published
- 2019
- Full Text
- View/download PDF
44. A survey of parabens in commercial pharmaceuticals from China and its implications for human exposure
- Author
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Zi-Feng Zhang, Zhong-Yang Lin, Li-Yan Liu, Yi-Fan Li, Mohammed O.A. Mohammed, Xue Zhao, Wan-Li Ma, and Wei-Wei Song
- Subjects
0301 basic medicine ,Adult ,Male ,Preservative ,China ,Daily intake ,Parabens ,010501 environmental sciences ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Eating ,Frequency detection ,Anti-Infective Agents ,Asian People ,Surveys and Questionnaires ,Ingestion ,Humans ,Food science ,Child ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,General Environmental Science ,PROPYL PARABEN ,lcsh:GE1-350 ,Chromatography ,Preservatives, Pharmaceutical ,Environmental Exposure ,Orders of magnitude (mass) ,Paraben ,Anti-Bacterial Agents ,030104 developmental biology ,chemistry ,Pharmaceutical Preparations ,Human exposure ,Female ,Chromatography, Liquid - Abstract
Parabens are widely used as antimicrobial preservatives during pharmaceutical production. However, little information is available regarding the occurrence of parabens in commercial pharmaceuticals and their implications for human exposure. In this study, six commonly used parabens were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry with 100 commercial pharmaceuticals collected from China. Almost all of the pharmaceutical samples contained at least one kind of parabens with the detection frequency of 97%. The concentrations of Σ6parabens (sum of the six parabens) ranged from below MDL to 1256 ng/g, with mean and median values of 94.8 and 119 ng/g, respectively. Methyl paraben (MeP), ethyl paraben (EtP) and propyl paraben (PrP) were the predominant compounds. Significant positive correlation was observed between concentrations of MeP and PrP, indicating their co-applications in pharmaceuticals. Levels of Σ6parabens varied in different categories of pharmaceuticals and increased with their shelf lives. Based on the measured concentrations and daily ingestion rates of pharmaceuticals, the estimated daily intake (EDI) of parabens was calculated. The median values of EDIpharmaceutical for male adults, female adults and children were 4.05, 4.75 and 9.73 ng/kg-bw/day, respectively, which were three orders of magnitude lower than those from foodstuffs and personal care products (PCPs). It was firstly reported that the total exposure dose was 0.326 mg/kg-bw/day via foodstuffs, PCPs, and pharmaceuticals for Chinese female adults. Keywords: Parabens, Occurrence, Pharmaceutical, Implication, Human exposure
- Published
- 2016
45. Brominated flame retardants in the surrounding soil of two manufacturing plants in China: Occurrence, composition profiles and spatial distribution
- Author
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Wen-Long Li, Li-Na Qiao, Wei-Wei Song, Chun-Yan Huo, Zi-Feng Zhang, Yi-Fan Li, Wan-Li Ma, and Li-Yan Liu
- Subjects
China ,010504 meteorology & atmospheric sciences ,Soil test ,Health, Toxicology and Mutagenesis ,Environmental pollution ,010501 environmental sciences ,Toxicology ,Spatial distribution ,01 natural sciences ,Soil ,Polybrominated diphenyl ethers ,Manufacturing and Industrial Facilities ,Halogenated Diphenyl Ethers ,Soil Pollutants ,0105 earth and related environmental sciences ,Flame Retardants ,General Medicine ,Pollution ,Deposition (aerosol physics) ,Environmental chemistry ,Environmental science ,Composition (visual arts) ,Environmental Pollution ,Environmental Monitoring - Abstract
Surface soil samples were collected surrounding two brominated flame retardants (BFRs) manufacturing plants in China in August 2014 and analyzed for 23 polybrominated diphenyl ethers (PBDEs) and 8 novel brominated flame retardants (NBFRs). BDE209 and decabromodiphenylethane (DBDPE) were the predominant compounds in soil with the median levels of 1600 and 560 ng/g dw, respectively. The PBDEs profiles in soil samples were consistent with that of commercial product (comDecaBDE). The percentage contributions to total PBDEs decreased from higher to lower brominated homologues. Lower concentrations of NBFRs (excluding DBDPE) were detected in soil surrounding the two plants, suggesting they are byproducts or degradation products of the manufacturing activities. The concentrations of most BFRs dropped exponentially within 3-5 km of the manufacturing plants, suggesting recent deposition of these compounds to the soil. Directional distribution indicated that PBDEs and DBDPE concentrations were highest in the north direction of Plants 1. Three-day air parcel forward trajectories confirmed that the air parcel was responsible for the higher concentration of BFRs in the soil of north direction of the plant.
- Published
- 2015
46. Molecular dynamics simulations of cylindrical polyelectrolyte brushes in monovalent and multivalent salt solutions
- Author
-
Tie-Ju Liu, Xiao-Hui Niu, Qing-Hai Hao, Hong-Ge Tan, Qian Chen, Zhen Zheng, Li-Yan Liu, and Qing-Gong Song
- Subjects
Valence (chemistry) ,Ion exchange ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Computer Science Applications ,Ion ,chemistry.chemical_compound ,Molecular dynamics ,Monomer ,Molecular geometry ,Computational Theory and Mathematics ,chemistry ,Chemical physics ,Polymer chemistry ,Osmotic pressure ,Physical and Theoretical Chemistry ,0210 nano-technology ,Shape factor - Abstract
Molecular dynamics simulations are applied to investigate the cylindrical polyelectrolyte brushes in monovalent and multivalent salt solutions. By varying the salt valence and concentration, the brush thickness, shape factor of grafted chains, and distributions of monomers and ions in the solutions are studied. The simulation results show that the single osmotic pressure effect in the brush leads to changes in conformation in the presence of monovalent salt, while the ion exchange effect induces the collapse of the brushes in the multivalent salt solutions. Furthermore, the snapshots combined with the distributions of the end-monomers and the mean bond angles demonstrate a nonuniform stretching picture of the grafted chains, which is different with the chains tethered on the planar surface. The charge ratios between the ions trapped in the brush and the monomers are also calculated to elucidate the details of ion exchange process.
- Published
- 2016
- Full Text
- View/download PDF
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