19 results on '"Shiyin Li"'
Search Results
2. Heterogeneous Fenton-like removal of tri(2-chloroisopropyl) phosphate by ilmenite (FeTiO
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Dunyu, Sun, Xiaohan, Wang, Qiuyi, Ji, Shaogui, Yang, Huan, He, Shiyin, Li, Chenmin, Xu, Chengdu, Qi, Haiou, Song, and Yazi, Liu
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Titanium ,Ultraviolet Rays ,Iron ,Humans ,Oxidation-Reduction ,Organophosphates ,Water Pollutants, Chemical ,Flame Retardants ,Phosphates - Abstract
Tri(2-chloroisopropyl) phosphate (TCPP), a common organophosphate flame retardant, was frequently detected in the environment and posed threats to human health. In this work, the main component of ilmenite FeTiO
- Published
- 2022
3. Heterogeneous Fenton-like removal of tri(2-chloroisopropyl) phosphate by ilmenite (FeTiO3): Kinetic, degradation mechanism and toxic assessment
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Dunyu Sun, Xiaohan Wang, Qiuyi Ji, Shaogui Yang, Huan He, Shiyin Li, Chenmin Xu, Chengdu Qi, Haiou Song, and Yazi Liu
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,General Medicine ,General Chemistry ,Pollution - Published
- 2022
4. Methyl silicate promotes the oxidative degradation of bisphenol A by permanganate: Efficiency enhancement mechanism and solid-liquid separation characteristics
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Jing Li, Xin Hu, Juan Wang, Li Yin, Youru Yao, Yong Zhang, Huan He, Shaogui Yang, Lixiao Ni, and Shiyin Li
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Silicates ,Public Health, Environmental and Occupational Health ,Oxides ,General Medicine ,General Chemistry ,Pollution ,Oxidative Stress ,Manganese Compounds ,Phenols ,Environmental Chemistry ,Benzhydryl Compounds ,Oxidation-Reduction - Abstract
Permanganate (Mn (VII)) is an environmentally-friendly mild oxidant in the field of advanced oxidation treatment, however, manganese colloids are produced as byproducts, which is difficult to separate from water, resulting in secondary pollution. This study used potassium methyl silicates (PMS) as surface modifiers to improve the aggregation of colloidal particles by increasing the hydrophobicity of the colloidal surface, and then explored the oxidation of bisphenol A (BPA) by Mn (VII) under the influence of potassium methyl silicate and the solid-liquid separation performance of the reaction system. The results showed that PMS and sodium silicate (SS) substantially enhanced the degradation of BPA by Mn (VII), and the promotion effect of potassium methyl silicate was greater than that of sodium silicate. PMS provided not only enough adsorption sites for MnO
- Published
- 2021
5. Visible light promoted the removal of tetrabromobisphenol A from water by humic acid-FeS colloid
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Youru Yao, Xin Hu, Yong Zhang, Huan He, and Shiyin Li
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Polybrominated Biphenyls ,Public Health, Environmental and Occupational Health ,Water ,General Medicine ,General Chemistry ,Pollution ,Sunlight ,Environmental Chemistry ,Colloids ,Ferrous Compounds ,Humic Substances ,Water Pollutants, Chemical - Abstract
Ferrous sulfide (FeS) and humic acid (HA) are typical black substances in black bloom water. Based on the strong reduction ability of FeS and the photosensitivity of HA, the transformation of toxic organic pollutants by the combination of FeS and HA (HA-FeS) is not clear. In order to explore this issue, the stability of HA-FeS was analyzed by measuring the hydrodynamic diameter and zeta potential of HA-FeS, and then the removal mechanism and possible degradation pathway of tetrabromobisphenol A (TBBPA) by HA-FeS under continuous illumination were discussed. The results showed that the hydrodynamic diameter of FeS was reduced and the stability of FeS was improved, and it was easily suspended after FeS combined with the HA in the water. The combination of HA and FeS promoted the removal of TBBPA in water, no matter it was in the presence or absence of light. Besides, compared with the absence of light, the removal efficiency of TBBPA was improved by HA-FeS with continuous light. There were two reasons for the increase in the removal efficiency of TBBPA by HA-FeS. On the one hand, Fe
- Published
- 2021
6. Inhibitory effect and mechanism of linoleic acid sustained-release microspheres on Microcystis aeruginosa at different growth phases
- Author
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Gu Guoxiu, Peifang Wang, Shiyin Li, Hanqi Wu, Rong Shiyi, Hu Lingling, Feifei Yue, Danye Li, Na Wang, and Lixiao Ni
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0301 basic medicine ,Microcystis ,Environmental Engineering ,Antioxidant ,Membrane permeability ,Health, Toxicology and Mutagenesis ,medicine.medical_treatment ,Linoleic acid ,010501 environmental sciences ,01 natural sciences ,Algal bloom ,Linoleic Acid ,Superoxide dismutase ,Lipid peroxidation ,03 medical and health sciences ,chemistry.chemical_compound ,medicine ,Environmental Chemistry ,Microcystis aeruginosa ,Food science ,0105 earth and related environmental sciences ,biology ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,biology.organism_classification ,Pollution ,Microspheres ,030104 developmental biology ,chemistry ,Catalase ,biology.protein ,Oxidation-Reduction - Abstract
Environment-friendly algaecides based on allelopathy have been extensively studied to control harmful algal blooms (HABs). The inhibitory effects of linoleic acid (LA) sustained-release microspheres on different cell densities of Microcystis aeruginosa (M. aeruginosa) at different growth phases were studied. The results showed that the growth of M. aeruginosa could be inhibited within 4 days and the constant inhibitory rate with initial algal density of 8 × 105 cells∙mL−1 (exponential phase) was up to 96% compared with control. The chlorophyll-a content in the treatment group had the same change trend with the algal density and declined significantly at day 20th, which suggested that the microspheres could promote the degradation of chlorophyll-a. The activities of superoxide dismutase (SOD) and catalase (CAT) increased gradually within 5 days but then declined sharply, which indicated that LA microspheres could cause oxidative damage to M. aeruginosa during the process of inhibition and reduce the activities of antioxidant enzymes. In addition, the concentration of oxygen free radical (O2−) increased at day 10th and rose constantly, and the content of malodialdehyde (MDA) increased to 2.7 times as much as control at day 20th. Furthermore, the content of protein, nucleic acid and the conductivity in culture solution showed a significant rise. These results showed that algal cell membrane lipid peroxidation occurred and the membrane permeability increased, accompanied by the damage of cell membrane. To sum up, the destruction of algal cell membrane is the main mechanism of LA microspheres inhibiting algal growth.
- Published
- 2018
7. Comparing the effects of humic acid and oxalic acid on Pb(II) immobilization by a green synthesized nanocrystalline hydroxyapatite
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Shiyin Li, Ruiming Han, Chunmiao Zheng, Yijun Yao, Yi Shao, Yong Zhang, Wei Wei, Wen-Ming Xie, Xuan Han, and Wei Zhao
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chemistry.chemical_classification ,Environmental Engineering ,Environmental remediation ,Chemistry ,Precipitation (chemistry) ,Health, Toxicology and Mutagenesis ,Oxalic Acid ,Oxalic acid ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Nanocrystalline material ,chemistry.chemical_compound ,Durapatite ,X-ray photoelectron spectroscopy ,Lead ,Dissolved organic carbon ,Environmental Chemistry ,Primary component ,Humic acid ,Soil Pollutants ,Humic Substances ,Nuclear chemistry - Abstract
Dissolved organic matter (DOM) is one of the most significant parameters to affect the remediation efficiency of Pb(II) by apatites. Numerous studies chose humic substances as a surrogate of DOM to investigate its influence on Pb(II) immobilization. However, the effect of low-molecular-weight organic acids such as oxalic acid (OA), which is ubiquitous in the environment and a primary component of DOM, in immobilizing Pb(II) was still not fully understood. Herein, humic acid (HA) and OA were examined to distinguish their influence on Pb(II) immobilization by a green synthesized nanocrystalline hydroxyapatite (nHAP). Various parameters were considered to evaluate the removal performance of nHAP towards Pb(II) as affected by HA/OA. Results indicated that Pb(II) immobilization was significantly promoted in the coexistence of OA owing to the precipitation of hydroxypyromorphite (HPY) as well as PbC2O4, but was independent on the addition sequence and slightly hindered by HA, disclosing that Pb(II) preferred to bind directly with nHAP instead of via HA. Characterization of the Pb(II) loaded solids by multiple technologies revealed that HPY was the predominant precipitate both in the absence and presence of HA, while the formation of PbC2O4 was preferred over that of HPY in the existence of OA. X-ray photoelectron spectroscopy indicated that PbC2O4 was the prevalent solid phase with the ratio of 62.97% after Pb(II) immobilization by nHAP in the presence of OA. These findings implied that the transformation efficiency of Pb(II) to HPY by apatites can be overestimated in the presence of OA due to the precipitation of PbC2O4.
- Published
- 2021
8. Enhancing the performance of pollution degradation through secondary self-assembled composite supramolecular heterojunction photocatalyst BiOCl/PDI under visible light irradiation
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Shaogui Yang, Chenmin Xu, Zhe Xu, Xinying Cheng, Qiuyi Ji, Jiapeng Hu, Limin Zhang, Weiming Xiang, Huan He, Chengdu Qi, Wu Yijie, and Shiyin Li
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Environmental Engineering ,Materials science ,Light ,Surface Properties ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Photochemistry ,Imides ,01 natural sciences ,Catalysis ,law.invention ,chemistry.chemical_compound ,Phenols ,law ,Rhodamine B ,Methyl orange ,Environmental Chemistry ,Phenol ,Electron paramagnetic resonance ,Perylene ,0105 earth and related environmental sciences ,Aqueous solution ,Rhodamines ,Public Health, Environmental and Occupational Health ,Heterojunction ,General Medicine ,General Chemistry ,Pollution ,020801 environmental engineering ,Nanostructures ,chemistry ,Photocatalysis ,Azo Compounds ,Bismuth ,Water Pollutants, Chemical ,Visible spectrum - Abstract
A novel n-n type inorganic/organic heterojunction of flaky-like BiOCl/PDI photocatalyst was constructed by water bath heating method. Meanwhile, a simple method - secondary self-assembly was used to prepare the BiOCl/PDI with a special band structure. The photocatalytic activities were evaluated by degrading aqueous organic pollutants under visible light (λ > 420 nm). The removal rates of 5 mg L−1 phenol (non-ionic type), methyl orange (MO, anionic type), rhodamine B (RhB, cationic type) and 10 mg L−1 RhB by secondary self-assembly BiOCl/PDI (BiOCl/PDI-2) were 8.0%, 3.4%, 27.8% and 78.9% higher than self-assembly BiOCl/PDI (BiOCl/PDI-1) under visible light (λ > 420 nm). The better photocatalytic activity for BiOCl/PDI-2 was attributed to the optimization of energy-band structures, which arose from different exposed surfaces, narrower interplanar spacing and stronger visible light absorption performance. Under acidic condition, BiOCl/PDI-2 showed a good photocatalytic activity, which was not affected by neutral ionic intensity and had good recycling properties. Moreover, the photocatalytic mechanism was explored by free radical capture test and electron paramagnetic resonance (EPR), and contribution of active species was calculated. The main active species of BiOCl/PDI-2 were ·O2−, 1O2 and h+. Our work may provide a route to design efficient inorganic/organic heterojunctions for organic pollutants degradation.
- Published
- 2020
9. Transport of arsenic loaded by ferric humate colloid in saturated porous media
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Li Yin, Shiyin Li, Yong Zhang, Dongbao Zhou, Youru Yao, Shaogui Yang, Cheng He, Huan He, HongGuang Sun, and Na Mi
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endocrine system ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Analytical chemistry ,Ionic bonding ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,Dispersion (geology) ,complex mixtures ,01 natural sciences ,Ferric Compounds ,Arsenic ,Diffusion ,Colloid ,medicine ,Water Movements ,Environmental Chemistry ,Colloids ,Particle Size ,Humic Substances ,0105 earth and related environmental sciences ,Molecular diffusion ,Chemistry ,digestive, oral, and skin physiology ,Osmolar Concentration ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Quartz ,Pollution ,020801 environmental engineering ,Ionic strength ,Ferric ,Particle size ,Porosity ,medicine.drug - Abstract
The transport behavior of arsenic (As(V)) loaded by ferric humate (HA-Fe) colloid, denoted as HA-Fe/As(V), moving in a saturated quartz sand column, was tested in the laboratory under varying pH values, ionic strengths, and HA and Fe(III) content. The time-fractional advection-dispersion equation (fADE) model was then employed to analyze the observed migration of HA-Fe/As(V). Results showed that the stability of the HA-Fe colloid exhibited an upward trend with an increasing pH and HA content. An increasing HA content led to a decrease in the particle size of the HA-Fe colloid. However, the effect of Fe(III) concentration on colloidal particle size exhibited the opposite phenomenon. The ability of the HA-Fe colloid to load As(V) gradually increased with the increase of the Fe(III) concentration. During the co-transport of the HA-Fe/As(V) colloid, transport of As(V) was promoted with increasing pH, increasing HA and Fe(III) content, and decreasing ionic strength in the saturated porous medium. The transport behavior of As(V) can be well fitted by the fADE model. The model analysis revealed that sub-diffusion of As(V) was weakened in the HA-Fe/As(V) colloid with high HA content. Sub-diffusion of As(V) in the low pH colloid was stronger than that of the high-pH colloid, and the molecular diffusion and mechanical dispersion were more weakened in the high-pH colloid than that of the low-pH colloid. When observing varying ionic strengths, As(V) exhibited stronger sub-diffusion in the HA-Fe/As(V) colloid with a higher ionic strength. As for the Fe(III) content, transport of As(V) was mainly affected by sub-diffusion in the HA-Fe/As(V) colloid with a low Fe(III) content. These findings provided direct and necessary insights into the effects of the HA-Fe colloid on the migration of As(V) throughout saturated porous media under different hydrochemical conditions found in natural environments.
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- 2019
10. Degradation of tri(2-chloroisopropyl) phosphate by the UV/H
- Author
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Huan, He, Qiuyi, Ji, Zhanqi, Gao, Shaogui, Yang, Cheng, Sun, Shiyin, Li, and Limin, Zhang
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Kinetics ,Porphyrins ,Ultraviolet Rays ,Hydrogen Peroxide ,Wastewater ,Phosphates - Abstract
A photodegradation technology based on the combination of ultraviolet radiation with H
- Published
- 2019
11. Enhanced Cr(VI) removal from water using a green synthesized nanocrystalline chlorapatite: Physicochemical interpretations and fixed-bed column mathematical model study
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Wei Wei, Xiangnan Yu, Xuan Han, Yong Zhang, Chunmiao Zheng, and Shiyin Li
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Chromium ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Oxyanion ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Apatite ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,X-ray photoelectron spectroscopy ,Apatites ,Environmental Chemistry ,Fourier transform infrared spectroscopy ,Hexavalent chromium ,0105 earth and related environmental sciences ,Chemistry ,Public Health, Environmental and Occupational Health ,Water ,Langmuir adsorption model ,General Medicine ,General Chemistry ,Models, Theoretical ,Pollution ,Nanocrystalline material ,020801 environmental engineering ,Kinetics ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,symbols ,Water Pollutants, Chemical - Abstract
Apatite-based minerals have attracted much attention in the remediation of heavy metal-contaminated environment. However, exploring apatite with efficient adsorption performance for inorganic oxyanions such as Cr(VI) remains a challenge. Herein, a novel nanocrystalline chlorapatite (ClAP) was promptly prepared by a green method using eggshell wastes as calcium source with the purpose to enhance Cr(VI) adsorption capability. The generated ClAP was characterized by XRD, SEM-EPMA, TEM, FTIR, and BET analyses. Batch and column experiments were subsequently carried out to explore the influencing factors, adsorption capacity and removal mechanism. Results showed that ClAP exhibited excellent stability and adsorption performance for Cr(VI) (63.47 mg g−1), which was much greater than that of hydroxyapatite and most reported materials. The adsorption process was fitted well by the pseudo-second-order model and the Langmuir model. In fixed bed column experiments, a novel time-fractional derivative model exhibited much better suitability in interpreting the observed breakthrough curves of Cr(VI) than traditional models. Furthermore, the reusability of ClAP in column was evaluated. Results showed that the adsorption capacity maintained well after consecutively reused for five cycles. Studies of the effect of pH, as well as FTIR and XPS investigations indicated that Cr(VI) adsorption was mainly ascribed to electrostatic interactions and surface complexation, while the reduction of Cr(VI) to the low-toxicity Cr(III) also existed in the adsorption process. The ClAP adsorbent was also successfully used for Cr(VI) remediation from real wastewater. Hence, nanocrystalline ClAP can be a promising material for enhancing the elimination of oxyanion contaminants such as Cr(VI) from water.
- Published
- 2021
12. Synthesis and application of magnetic materials-barium ferrite nanomaterial as an effective microwave catalyst for degradation of brilliant green
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Chenmin Xu, Hongzhe Chen, Huan He, Cheng Sun, Chengdu Qi, Shiyin Li, Shaogui Yang, Zhe Xu, and Chen Huangbo
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Environmental Engineering ,Materials science ,Scanning electron microscope ,Health, Toxicology and Mutagenesis ,Barium Compounds ,0208 environmental biotechnology ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Ferric Compounds ,01 natural sciences ,Catalysis ,Magnetics ,chemistry.chemical_compound ,Microscopy, Electron, Transmission ,X-Ray Diffraction ,X-ray photoelectron spectroscopy ,Environmental Chemistry ,Fourier transform infrared spectroscopy ,Coloring Agents ,Microwaves ,Barium ferrite ,0105 earth and related environmental sciences ,Triphenylmethane ,Photoelectron Spectroscopy ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Nanostructures ,020801 environmental engineering ,Quaternary Ammonium Compounds ,Brilliant green ,chemistry ,Catalytic oxidation ,Microscopy, Electron, Scanning ,Nuclear chemistry - Abstract
In this work, magnetic separably barium ferrite nanomaterial (BaFeO) was synthesized via citrate acid assisted sol-gel combustion method. Subsequently, X-ray diffraction (XRD), scanning electron microscopy-energy dispersion spectroscopy (SEM-EDS), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) were applied for its structural, morphological, and electromagnetic characterization. In addition, microwave (MW) absorption and thermal conversion test results indicated the BaFeO had electrothermal rather than magnetothermal conversion capacity. Meanwhile, the synthesized BaFeO showed satisfactory performance in both eliminating and mineralization of a typical triphenylmethane dye, brilliant green (BG), in MW-induced catalytic oxidation (MICO) process without extra oxidant addition. Besides, changes in element valence and content of BaFeO before and after MICO process investigated with XRD, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) showed its relatively stable properties. Furthermore, transition oxygen species involved in MICO process was deduced as lattice oxygen species. Then, the possible degradation pathway of BG was proposed as demethylation, open-loop of triphenylmethane, releasing one ring, formation of the benzene ring and the ultimate mineralization based on the degradation intermediates tentatively identified by gas chromatography mass spectrometry (GC/MS) and liquid chromatography mass spectrometry (LC/MS), respectively. Finally, ecotoxicity analysis by ecological structure activity relationships (ECOSAR) showed that both the acute and chronic toxicity of these intermediates were lower than that of parent BG. These findings are important regarding the development of efficient catalysts in MICO process for degradation of BG analogues in wastewater.
- Published
- 2020
13. Degradation of tri(2-chloroisopropyl) phosphate by the UV/H2O2 system: Kinetics, mechanisms and toxicity evaluation
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Cheng Sun, Shaogui Yang, Limin Zhang, Qiuyi Ji, Zhanqi Gao, Shiyin Li, and Huan He
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Environmental Engineering ,Chemistry ,Health, Toxicology and Mutagenesis ,Luminescent bacteria ,0208 environmental biotechnology ,Kinetics ,Public Health, Environmental and Occupational Health ,02 engineering and technology ,General Medicine ,General Chemistry ,010501 environmental sciences ,Phosphate ,01 natural sciences ,Pollution ,020801 environmental engineering ,chemistry.chemical_compound ,Wastewater ,Yield (chemistry) ,Ultrapure water ,Environmental Chemistry ,Degradation (geology) ,Photodegradation ,0105 earth and related environmental sciences ,Nuclear chemistry - Abstract
A photodegradation technology based on the combination of ultraviolet radiation with H2O2 (UV/H2O2) for degrading tri(chloroisopropyl) phosphate (TCPP) was developed. In ultrapure water, a pseudo-first order reaction was observed, and the degradation rate constant reached 0.0035 min−1 (R2 = 0.9871) for 5 mg L−1 TCPP using 250 W UV light irradiation with 50 mg L−1 H2O2. In detail, the yield rates of Cl− and PO43− reached 0.19 mg L−1 and 0.58 mg L−1, respectively. The total organic carbon (TOC) removal rate was 43.02%. The pH value of the TCPP solution after the reaction was 3.46. The mass spectrometric detection data showed a partial transformation of TCPP into a series of hydroxylated and dechlorinated products. Based on the luminescent bacteria experimental data, the toxicity of TCPP products increased obviously as the reaction proceeded. In conclusion, degradation of high concentration TCPP in UV/H2O2 systems may result in more toxic substances, but its potential application for real wastewater is promising in the future after appropriate optimization, domestication and evaluation.
- Published
- 2019
14. Assessing bioaccessibility and bioavailability of chlorinated organophosphorus flame retardants in sediments
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Dong-Lin Zhu, Cheng Sun, Jiehong Guo, Shiyin Li, Shaogui Yang, Huan He, Limin Zhang, and Zhanqi Gao
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Lumbriculus variegatus ,Geologic Sediments ,Environmental Engineering ,Halogenation ,Polymers ,Health, Toxicology and Mutagenesis ,Tenax ,010501 environmental sciences ,Solid-phase microextraction ,01 natural sciences ,chemistry.chemical_compound ,Environmental Chemistry ,Animals ,Fiber ,Oligochaeta ,Solid Phase Microextraction ,0105 earth and related environmental sciences ,Flame Retardants ,Chromatography ,biology ,010401 analytical chemistry ,Extraction (chemistry) ,Public Health, Environmental and Occupational Health ,Sediment ,General Medicine ,General Chemistry ,Phosphate ,biology.organism_classification ,Pollution ,Organophosphates ,0104 chemical sciences ,Bioavailability ,chemistry ,Environmental chemistry ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The distribution of chlorinated organophosphate flame retardants (OPFRs) in sediments has been well documented, but the study about their bioavailability remains lacking. This study investigated the applicability of solid phase microextraction (SPME) fiber and Tenax extraction to predict the bioavailability of two chlorinated OPFRs: tri(2-chloroisopropyl) phosphate and tri(1,3-dichloro-2-isopropyl) phosphate, in sediments. Our results showed that both SPME fiber and Tenax extracted concentrations correlated significantly with the measured concentrations in the aquatic worm (Lumbriculus variegatus). We also measured the Tenax extracted concentrations at 6 and 24 h, and a strong linear relationship between these two time durations was found. In addition, the 6-h Tenax extracted concentrations also significantly correlated with the SPME fiber extracted concentrations, and the Tenax extracted concentrations were much higher than the SPME fiber extracted concentrations. These results demonstrate the efficiency of SPME and Tenax extraction methods to predict the bioavailability of chlorinated OPFRs in sediments, and it was found that the Tenax extraction is more promising than the SPME extraction.
- Published
- 2017
15. Preparation and characterization of anti-algal sustained-release granules and their inhibitory effects on algae
- Author
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Yiping Li, Lixiao Ni, Kumud Acharya, Yong Li, Shiyin Li, and Gaoxiang Ren
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Microcystis ,Environmental Engineering ,Alginates ,Drug Compounding ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,Calcium ,Chloride ,Calcium Chloride ,chemistry.chemical_compound ,Glucuronic Acid ,parasitic diseases ,medicine ,Environmental Chemistry ,Microcystis aeruginosa ,Artemisinin ,Mode of action ,Sugar ,Microbial Viability ,Chromatography ,biology ,Hexuronic Acids ,Granule (cell biology) ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Eutrophication ,biology.organism_classification ,Pollution ,Artemisinins ,Microspheres ,chemistry ,Delayed-Action Preparations ,Glutaraldehyde ,Water Microbiology ,Disinfectants ,medicine.drug - Abstract
The objectives of this work were to prepare and characterize an anti-algal sustained-release granule, then study its mode of action on Microcystis aeruginosa. The anti-algal sustained-release granule was prepared with artemisinin using alginate–chitosan microcapsule technology and characterized by a high performance liquid chromatography with an evaporative light-scattering detector, Fourier transform infrared spectral analysis, and a scanning electron microscope. The optimum preparation (in %, w/v) using the orthogonal method was: 2.5 sodium alginate; 0.25 chloride; 0.6 artemisinin; 2 calcium chloride; and 1.5 mL of the cross-linking agent, glutaraldehyde. These artemisinin sustained-release granules had a high encapsulation efficiency (up to 68%) and good release properties (release time of more than 40 d). Artemisinin sustained-release granules released cumulatively in a solution containing M. aeruginosa, and the stress on algae increased gradually within 30 d. Artemisinin sustained-release granules decreased the content of the soluble protein, Chlorophyll a in 30 d, increased the superoxide dismutase activity of M. aeruginosa, but exerted no effect on the soluble sugar content. Compared to direct dosing of artemisinin, algae can be inhibited longer and more effectively by the artemisinin sustained-release granules. The results of our research can aid in the development of new anti-algal sustained-release granules and lead to further study of their application in the field.
- Published
- 2013
16. Effects of algae growth on cadmium remobilization and ecological risk in sediments of Taihu Lake
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Xiang Ye, Hong Geng, Jiajun Xu, Peifang Wang, Dandan Li, Yiping Li, Lili Su, Kumud Acharya, Lixiao Ni, Yi Li, and Shiyin Li
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Geologic Sediments ,Environmental Engineering ,Microcystis ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,010501 environmental sciences ,01 natural sciences ,Algal bloom ,Risk Assessment ,Sediment–water interface ,Environmental Chemistry ,0105 earth and related environmental sciences ,Cadmium ,biology ,Ecology ,fungi ,Public Health, Environmental and Occupational Health ,Environmental engineering ,food and beverages ,Sediment ,General Medicine ,General Chemistry ,Eutrophication ,Hydrogen-Ion Concentration ,biology.organism_classification ,Pollution ,Oxygen ,Lakes ,chemistry ,Environmental chemistry ,Environmental science ,Microcosm ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Indoor simulation experiment with 2.76 L microcosms using sediment from Taihu Lake were conducted to investigate the relationship between algae bloom and heavy metals release into a lake aquatic environment. The results showed that Microcystic aeruginosa (M. aeruginosa) growth can enhance cadmium (Cd) mobilization from sediments to overlying water due to increasing pH and DO content of overlying water and changing the redox condition of surface sediment (0-2 cm) from weak oxidation to weak reduction. The dissolved Cd concentration in overlying water can be decreased during algal growth process. The remobilization of Cd from sediment can effectively reduce the ecological risk of total Cd in sediments. The results of this study showed that both Igeo and Er(i) can be used to effectively evaluate the ecological risk of heavy metal Cd in different fractions.
- Published
- 2015
17. Effect of linoleic acid sustained-release microspheres on Microcystis aeruginosa antioxidant enzymes activity and microcystins production and release
- Author
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Yiping Li, Guoxiang Wang, Kumud Acharya, Yong Li, Shiyin Li, Lixiao Ni, Peifang Wang, and Jie Xiaoting
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Chlorophyll ,Environmental Engineering ,Antioxidant ,Microcystis ,Microcystins ,Health, Toxicology and Mutagenesis ,medicine.medical_treatment ,Linoleic acid ,Antioxidants ,Linoleic Acid ,chemistry.chemical_compound ,medicine ,Extracellular ,Environmental Chemistry ,Microcystis aeruginosa ,Food science ,Super oxide dismutase ,biology ,Chlorophyll A ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Eutrophication ,biology.organism_classification ,Pollution ,Microspheres ,Biochemistry ,chemistry ,Catalase ,Delayed-Action Preparations ,biology.protein ,Marine Toxins ,Oxidation-Reduction ,Peroxidase - Abstract
The objective of this work was to identify the optimal dose range for good anti-algal effect of linoleic acid (LA) sustained-release microspheres and investigate their impact on the antioxidant enzymes (super oxide dismutase, Catalase and Peroxidase) activity changes of Microcystis aeruginosa, as well as the production and release of microcystins (MCs). Based on measured changes in algal cell density and inhibitory ratio (IR), the optimal dose of LA microspheres was 0.3 g L(-1) with over 90% of IR in this study. The Chlorophyll a content and antioxidant enzymes activity in the LA microspheres group decreased markedly until beyond the minimal detection limit after 16 d and 9 d, respectively. In addition, LA microspheres demonstrated no significant impact on the extracellular release of MCs during the culturing period. The amount of intracellular microcystin-LR (MC-LR) per 10(6) algal cells in LA microspheres group was highest among all groups during the whole experimental process. Under the sustained stress of LA released from LA microspheres, the LA microspheres could decrease the production and release of algal toxins. There was no increase in the total amount of MC-LR in the algal cell culture medium. These indicated that LA sustained-release microspheres represent a high degree of ecological safety and their practical applications for the treatment of water undergoing algal blooms need further study.
- Published
- 2014
18. Characterization of unsaturated fatty acid sustained-release microspheres for long-term algal inhibition
- Author
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Yong Li, Yiping Li, Shuzhen Hu, Shiyin Li, Lixiao Ni, Peifang Wang, Kumud Acharya, and Jie Xiaoting
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Thermogravimetric analysis ,Environmental Engineering ,Microcystis ,Scanning electron microscope ,Alginates ,Health, Toxicology and Mutagenesis ,Linoleic acid ,High-performance liquid chromatography ,Linoleic Acid ,chemistry.chemical_compound ,Glucuronic Acid ,Environmental Chemistry ,Microcystis aeruginosa ,Thermal stability ,Unsaturated fatty acid ,Chromatography ,biology ,Hexuronic Acids ,Thermal decomposition ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,biology.organism_classification ,Pollution ,Microspheres ,chemistry ,Delayed-Action Preparations ,Fatty Acids, Unsaturated - Abstract
The unsaturated fatty acid (linoleic acid) sustained-release microspheres were prepared with linoleic acid (LA) using alginate–chitosan microcapsule technology. These LA sustained-release microspheres had a high encapsulation efficiency (up to 62%) tested by high performance liquid chromatography with a photo diode array. The dry microspheres were characterized by a scanning electron microscope, X-ray diffraction measurement, dynamic thermogravimetric analysis and Fourier transform infrared spectral analysis. The results of characterization showed that the microspheres had good thermal stability (decomposition temperature of 236 °C), stable and temperature independent release properties (release time of more than 40 d). Compared to direct dosing of LA, LA sustained-released microspheres could inhibit Microcystis aeruginosa growth to the non-growth state. The results of this study suggested that the LA sustained-release microspheres may be a potential candidate for algal inhibition.
- Published
- 2014
19. Isolation and identification of an anti-algal compound from Artemisia annua and mechanisms of inhibitory effect on algae
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Kumud Acharya, Lixiao Ni, Shiyin Li, and Xiangyang Hao
- Subjects
Environmental Engineering ,Microcystis ,Health, Toxicology and Mutagenesis ,Artemisia annua ,Acetates ,Column chromatography ,Algae ,Botany ,Alkanes ,medicine ,Environmental Chemistry ,Microcystis aeruginosa ,Artemisinin ,Mode of action ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Plant Extracts ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Ascorbic acid ,biology.organism_classification ,Pollution ,Anti-Bacterial Agents ,Biochemistry ,chemistry ,medicine.drug - Abstract
The goals of this work were to isolate and identify an anti-algal compound from extracts of Artemisia annua and study its mode of action on Microcystis aeruginosa. The anti-algal compound was isolated from the extracts using column chromatography and activity-guided fractionation methods. Artemisinin with strong anti-algal activity was identified by gas chromatography-mass spectrometry and (1)H Nuclear Magnetic Resonance. The EC(50) of artemisinin on M. aeruginosa was 3.2mg L(-1). Artemisinin decreased the soluble protein content and increased the superoxide dismutase activity and ascorbic acid content of M. aeruginosa, but exerted no effect on soluble sugar content. The results suggested the mode of action of artemisinin on algae may primarily be the increasing level of reactive oxygen species in algae cells. The results of our research could aid in the development of new anti-algal substances and lead to further study of mechanisms of inhibitory effect on algae.
- Published
- 2012
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