Search

Oil and natural gas (O&NG) exploration presents a significant source of atmospheric volatile organic compounds (VOCs), which are central players of tropospheric chemistry and contribute to formations of ozone (O3) and secondary organic aerosols. The impacts of O&NG extraction on regional air quality have been investigated in recent years in North America, but have long been overlooked in China. To assess the impacts of O&NG exploration on tropospheric O3 and regional air quality in China, intensive field observations were conducted during February–March and June–July 2017 in the Yellow River delta, an oil extraction region in northern China. Very high concentrations of ambient VOCs were observed at a rural site, with the highest alkane mixing ratios reaching 2498 ppbv. High- O3 episodes were not encountered during wintertime but were frequently observed in summer. The emission profiles of VOCs from the oil fields were directly measured for the first time in China. The chemical budgets of ROx radicals and O3 were dissected with a detailed chemical box model constrained by in situ observations. The highly abundant VOCs facilitated strong atmospheric oxidation capacity and O3 formation in the region. Oxygenated VOCs (OVOCs) played an essential role in the ROx primary production, OH loss, and radical recycling. Photolysis of OVOCs, O3 , and HONO as well as ozonolysis reactions of unsaturated VOCs were major primary sources of ROx. NOx was the limiting factor of radical recycling and O3 formation. This study underlines the important impacts of O&NG extraction on atmospheric chemistry and regional air quality in China. [ABSTRACT FROM AUTHOR]

Abstract China is one of the largest consumers of natural resources worldwide and this has led to increasing pressure on scarce resources. An understanding of the use of natural resources in Chinese economy is thus important to mitigate resource scarcity at the global scale. This study investigates the natural resource flows within the economic system of China from the raw material extraction to the final production. We identify critical sectors using a variety of methods and consider the various roles of the sectors in the consumption of natural resources in the economy. We also identify critical supply chain paths using a structural path analysis (SPA). The results show that the intermediate-based approach complements the traditional direct and consumption-based approaches and highlights critical sectors for the consumption of domestic resource extraction in China such as Crop cultivation , Cotton and chemical fiber products , and Glass products. The most critical supply chain paths originate from the resource extraction sectors and ultimately end in the Construction sector (e.g., stone, lime, plaster, ceramic), given that more than half of the domestic resource extraction is driven by the Construction sector. To reduce the consumption of domestic resource extraction in China, the government should focus on the critical sectors and supply chain paths identified using our methods for targeted policy interventions. Graphical abstract Image 1 Highlights • The resource flows from raw material extraction to final production are covered. • The critical sectors are evaluated with different concerns. • Crop, cotton, and glass have a critical role in natural resource consumption. • More than half of domestic resource extraction is induced by the construction sector. [ABSTRACT FROM AUTHOR]

Selenium (Se) is an essential trace element for humans. In order to investigate how soil Se is influenced by topography and soil properties, we selected Yongjia County, an area with mountainous topography, as a study area. This study used cultivated soil data to comprehensively analyze the effects of topography and soil properties on Se mobility and bioavailability and to identify the key factors influencing Se distribution in the environment. Factors considered in this study were elevation, slope, topographic wetness index, the coefficient of weathering and eluviation, pH, organic matter, and Fe 2 O 3 . The concentration of total soil Se (0.382 ± 0.123 mg kg −1 ) was far higher than the background value of soil in China, and 98% of the soil samples were classified as having moderate Se levels (>0.175 mg kg −1 ), indicating Yongjia County is a Se-rich region in China. Phosphate extracted Se accounted for an average of 9% of the total Se and was significantly associated with soil total Se, Fe 2 O 3 , pH, and the coefficient of weathering and eluviation. Fe 2 O 3 primarily controlled Se adsorption, fixation, and availability in soil. Under the geo-environmental conditions in the study area, the total Se in the soil increased first and then decreased with increases in elevation, slope, and the topographic wetness index, and the phosphate extracted Se showed similar patterns except for the elevation. The findings showed that topographical attributes and soil physicochemical properties synthetically influenced the distribution and bioavailability of Se in soil. [ABSTRACT FROM AUTHOR]

In this work, ultrasonic-assisted reductive extraction of matrine from Sophorae tonkinesis was studied for the first time. During this process, sodium metabisulfite was added as a reducing agent in order to covert maximum amount of oxymatrine, sophocarpine, and oxysophocarpine to matrine. After optimization by response surface methodology, the extraction yield of matrine was found to be 2.03%, much higher than the yield obtained through traditional extraction method. After filtration, H103-macroporous adsorption resin column chromatography, concentration, and recrystallization, matrine with 98.2% purity was obtained. [ABSTRACT FROM PUBLISHER]

The conception of special geologic bodies has been applied in this study to define and illustrate economic oil and gas reservoirs in sandbodies, which is helpful for hydrocarbon forecast and exploration. Using the comprehensive analysis of drilling, logging, seismic, seismic attribute extraction, and logging constrained inversion in 3D data volume, the special geologic bodies of the Shahejie Formation (P s ) in northern Qikou sag, which have good hydrocarbon potential, are identified and described under the constraint of sequence stratigraphic framework. The dimensions, geometry, and spatial distribution features of the special geologic bodies, as well as their inner architectures and sequence-structure patterns, are also ascertained. The geologic bodies evolved from relative centralization in the middle part of the lacustrine basin in the early stage of P s Formation, to several dispersive isolated parts in the later stage. This shows a small cycle interval (~2.5 Ma) at the end of the whole transgressive depositional process of P s1 (~7.5 Ma) during the expansion of the lake and relative lake level rise, with the control of sediments supply and fault-related subsidence, which effect the evolution of the sedimentary system. According to the relevance and regularity of the geologic bodies' development, different types of potential profitable reservoir traps, including the lithologic lenticular traps, lithologic updip pinchout traps, and structural-lithologic composite traps, can be preserved in the study area. In addition, the internal architecture models provide scientific basis for further hydrocarbon exploration in the frontier basin without enough data. [ABSTRACT FROM AUTHOR]

Zhundong coal from the Zhundong coalfield in in Xinjiang, China, is charactered by high content of Na. Na-related slagging of Zhundong coal is unclear. The aim of this study is to determine the influence of Na-based materials on the slagging characteristics of the coal. The raw coal was prepared by first removing Na by chemical extraction and subsequently impregnating it with the Na-based materials, such as NaCl, Na 2 SO 4 and NaAc. Laboratory slagging experiments in a muffle furnace were conducted using the mixtures of prepared Zhundong coal and quartz sand. It was found that the Na-based materials affected the slagging behavior of the coal in the order NaAc/Na 2 SO 4 > NaCl. For the mixtures with the NaCl additive, fusion was most noticeable at 900 °C. However, for the mixtures soaked with Na 2 SO 4 and NaAc, a monotonically increasing relationship was indicated between the degree of slagging and the temperature. Adding the Na-based materials to the coal resulted in increased Na content in the residual ash, especially in the instances with Na 2 SO 4 and NaAc additives. The formation of silicates, which were ascribed to the reactions between the Na-based materials and the SiO 2 , was the primary cause of slagging. Various mineral elements, especially Fe, were captured by Na 2 O, derived from the decomposition of Na 2 SO 4 or the combustion of NaAc, to exist in the form of a low-melting temperature eutectic. Additionally, the presence of Fe, Ca, K, and Mg in the ash aggravated slagging under the influence of Na 2 O. [ABSTRACT FROM AUTHOR]

The bioavailability of 22 heavy metals was investigated at 19 sampling sites in Tieguanyin tea garden in Anxi County, Fujian Province, southeastern China. Heavy metal concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and evaluated by geo-accumulation index ( I ). Dilute nitric acid extraction was used to evaluate biological activity. Cu, Pb, and Cd were highly bioavailable and most easily absorbed by tea trees. Heavy metal bioavailability in the surface soil was as the ratio of the effective state to the total amount. Cd had the highest I values, and the respective samples and sites were classified as moderately/strongly contaminated. Cd element is considered the main factor of heavy metal pollution in the tea garden in Anxi. The other heavy metals studied were present in lower concentrations; thus, the samples were classified as uncontaminated or slightly contaminated. [ABSTRACT FROM AUTHOR]

Umbilicaria esculenta has been used as a tonic food in China for several centuries owing to its pleasant flavor and health benefits. In this study, a water soluble polysaccharide, which we designated as UP2, with an average molecular weight of 3.33 × 105 Da, was isolated from U. esculenta cultivated in the Huangshan Mountain, by consecutive hot water extraction and anion-exchange chromatography. Gas chromatography analysis indicated that UP2 contained three kinds of monosaccharides, including mannose, glucose, and galactose at a molar ratio of 1.7:1.0:1.2. Linkage analysis of UP2 revealed the presence of (1 → 6)-linked glucosyl, (1 → 3,6)-linked glucosyl, t-linked galactosyl, (1 → 6)-linked galactosyl and (1 → 6)-linked mannosyl at a molar ratio of 0.7:4.6:4.1:2.2:9.1. Structural analysis determined that UP2 possessed a backbone consisting of (1 → 6)-linked β-D-glucopyranosyl and (1 → 6)-linked α-D-mannopyranosyl residues, which substituted at the O-3 position of (1 → 6)-linked β-D-glucopyranosyl residues by branches of (1 → 6)-linked α-D-galactopyranosyl and 1-linked β-D-galactopyranosyl residues. Immunostimulatory activity analysis showed that UP2 could stimulate the proliferation of RAW264.7 cells in a dose-dependent manner, and all the samples (20–500 μg/mL) were found to enhance nitric oxide production. The highest phagocytic activity of UP2 was observed at 200 μg/mL. Thus, UP2 may be a potential source of biological and pharmacological agents. [ABSTRACT FROM AUTHOR]

Interferometric synthetic aperture radar (InSAR) time-series analysis provides high spatial resolution and continuous temporal coverage for investigations of long-term ground displacement. Beijing, the capital city of China, has suffered from land subsidence since the 1950s, and extreme groundwater extraction has led to subsidence rates of > 100 mm/year. In this study, InSAR time-series analysis is performed on different data subsets to investigate the ground displacement at Capital International Airport, Beijing, between June 2003 and November 2013. The results show that the ground surface in the airport has deformed at different rates ranging from − 66.2 mm/year (sinking) to 8.2 mm/year (uplift) relative to the reference point. The projected vertical displacement rates agreed with measurements estimated from ground-leveling surveys, and the correlation coefficient of the fitting result is 0.96, with a standard deviation of 0.9 mm/year and a mean different of 2.0 mm/year. The runways and terminals have been affected by land subsidence to various degrees. Previous studies has indicated that long-term intense groundwater extraction is the main reason leading to land subsidence in this area. Other triggering factors, such as active faults, the quaternary compressible layers and urbanization, also have different degrees of contribution or impact on land subsidence in Beijing Plain. Furthermore, some interesting behaviors from groundwater (such as inter- and semi-annual variations) and subsidence, the relationship between them are also found in this study. [ABSTRACT FROM AUTHOR]

Zhundong coal is one of the most important coals in China due to its huge reserve, but it causes severe fouling and slagging problems when it is burnt in boilers for its high AAEMs (alkali and alkaline earth metal species) contents. Accurately determination of the occurrence modes and contents of AAEMs in Zhundong coals is a necessary step to overcome the ash-related problems. Nowadays, different researchers used different methods or procedures to determine AAEMs in Zhundong coals, and the data were scattering. Based on a series of experiments on the effects of extraction conditions, an improved extraction method with clearly defined conditions for each extraction step was proposed. 0.1 mol/L NH 4 Cl (pH = 8.5) instead of 1 mol/L NH 4 OAc (pH = 7) was used to extract the exchangeable AAEMs in Zhundong coals to avoid the high solubility of carbonates in the extraction solution. The improved method was more accurate and took much less time than the conventional one. With the proposed extraction method, the occurrence modes and contents of AAEMs in three Zhundong coals were measured. The results revealed that Na is mainly water soluble (Na w /Na total = 50–85%) which is halite or in the form of surface bound Na + , while Ca and Mg are mainly acid soluble (Ca ac /Ca total = 60–90%, Mg ac /Mg total = 45–90%) which are carbonates together with a little amount of sulfates. Exchangeable AAEMs organically bonded to the coal matrix are not the main occurrence mode of AAEMs. Acid insoluble Ca-species could be rankinite. The amounts of AAEMs in the same occurrence mode could be remarkably different among coals from different Zhundong district. The improved sequential extraction method can be extended to determine AAEMs in high carbonate-containing coals. [ABSTRACT FROM AUTHOR]

With the technology development and application of from coal to methane, more and more fixed-bed coal gasifiers are built up in China, bringing about much coal gasification tar residue, difficult to handle. A kind of coal gasification tar residue fetched from Lurgi gasifier was extracted with ethyl acetate. Effects of ethyl acetate quantity, stirring time, extraction temperature and extraction times were investigated in this paper. Results showed the optimum conditions were as follows: ratio of ethyl acetate volume to coal gasification tar residue mass was 2 mL/g, extraction time 30 min and extraction 3 times at room temperature of 18–25 °C. About 30.58% coal gasification tar residue was extracted. The extract and residue were analyzed by GC/MS, FTIR and DSC-TGA, respectively. Results revealed that coal gasification tar residue contained polycyclic aromatic compounds, which could be extracted easily by ethyl acetate. Boiling points of the extractable polycyclic aromatic compounds were between 150 °C and 400 °C, and 95% of the polycyclic aromatic compounds were 2–4 aromatic rings, which offered valuable chemical materials for further utilization. [ABSTRACT FROM AUTHOR]

The phenolic compounds and antioxidant activity of brown rice are well known but the extent to which phenolics and antioxidant activity varies within rice ( Oryza sativa) is not known. This study evaluated the natural variation of phenolic compounds in brown rice of the major cultivars currently grown in China. Free phenolics were extracted with chilled methanol, while bound phenolics were released and extracted by alkaline hydrolysis. There were significant differences in phenolic and flavonoid content between these cultivars and significant differences in bound and total phenolics between japonica and indica samples. Ferulic and p-coumaric acids were the major phenolic acids and existed in both free and bound forms, with the bound form of ferulic acid being a dominant phenolic compound in brown rice. Phenolic compounds were the major contributor to the antioxidant capacity of brown rice and bound phenolics contributed more than free phenolics as estimated using ABTS+ radical scavenging method. This study provides additional information on brown rice from japonica and indica subspecies and may assist in retaining or increasing phenolics and antioxidant activity in rice. [ABSTRACT FROM AUTHOR]

Over past decades, China has changed the manner in which coal mine methane (CMM) was treated: from mitigating its dangers as a mining hazard to developing its potential as an unconventional gas resource. CMM is rich in China coal seams. These coal seams normally have three distinct characteristics: high pressure, strong adsorption and low permeability. These characteristics require novel extraction and utilization technologies. This paper presented a comprehensive review of how these technologies evolve with time from underground extraction to surface drainage to combined surface-underground approach. Major conclusions include: (1) CMM is mainly drained through underground extraction technologies. In order to improve the drainage efficiency, these technologies usually combine with mining-induced stress relief or other active stimulation techniques and modern borehole sealing techniques; (2) Several innovative surface CMM extraction technologies have been proved as effective for Chinese CMM formation conditions, such as gob surface well extraction, stress-relieved seams surface well extraction, multi-branch horizontal directional surface well extraction, and multipurpose surface well extraction; (3) A combined surface-underground approach has been applied to Huainan and Jincheng coal mines. These applications represent the new development trend of CMM extraction and control in China; and (4) Apart from the CMM extraction technologies, utilization technologies also achieved significant progresses in China. The electricity generation and safe transportation technologies of low-concentration gas have also been developed to improve the gas utilization rate and guarantee the safe long distance and large flow transportation of low-concentration gas in China. The implementation of CMM extraction and utilization technologies has led to a large increase of coal production, gas extraction and utilization, and a significant reduction of fatality. [ABSTRACT FROM AUTHOR]

Modes of occurrence of Br in bituminous coal from China were extracted using sequential chemical extraction; coal combustion was simulated with a tube furnace, and the effects and mechanisms of combustion temperature, combustion time, O 2 flow rate and water vapor access on the Br release from bituminous coal were investigated. The results showed that the Br release rate increased with the increase of temperature, and 500–900 °C was the main stage of Br release. The Br occurred as water-soluble, ion exchangeable and organic fraction may be completely emitted before 700 °C, bound to carbonate and Fe–Mn oxide may be mainly emitted in 700–900 °C, and occurred in residual fraction which cannot be extracted using sequential chemical extraction can be largely emitted during combustion. Moreover, the Br release rate in bituminous coal increased with the increase of combustion time and O 2 flow rate, and more than 97% Br may be emitted at the given experimental condition of combustion temperature of 1000 °C, water vapor access, O 2 flow rate of 90 mL min −1 and combustion time of 20 min. During combustion, the Br in bituminous coal was transformed into HBr and easily taken out of the furnace with the help of water vapor, which indicated water vapor can obviously promote the Br release. The additive of SiO 2 can capture the Br effectively in the process of the coal combustion. [ABSTRACT FROM AUTHOR]

The wood samples of Populus euphratica Oliv. (Salicaceae) are common archaeological plant remains in the hot and arid regions of western China. However, it is difficult to identify P. euphratica wood based on traditional wood anatomical methods alone. DNA barcoding might provide a higher security for species identification. In this study, aged wood specimens stored for approximately 30, 60, and 80 years and archaeological wood up to 3600 years old were in focus to explore the potential of DNA extraction and PCR amplification for different-sized fragments, ranging between 100 and 800 bp, taken from wood stored for different periods. The results indicated that DNA fragments of more than 100 bp could be successfully retrieved from a wood specimen stored for about 80 years based on a modified Qiagen kit protocol. However, it was impossible to obtain DNA segments from the 3600-year-old wood according to the current extraction protocol. Moreover, it was deduced that two-stage PCR amplification could play a significant role in the analysis of DNA retrieved from aged wood materials. With the aid of phylogenetic analysis, based on the short DNA barcode rbcL-2 of 202 bp in length, it was possible to differentiate P. euphratica from the other species of the Populus genus. [ABSTRACT FROM AUTHOR]

Sediments in urban waterways of Guangzhou, China, were contaminated by a variety of chemicals and showed prevalent toxicity to benthic organisms. A combination of whole-sediment toxicity identification evaluation (TIE) and bioavailability-based extraction was used to identify the causes of sediment toxicity. Of the 6 sediment samples collected, 4 caused 100% mortality to Chironomus dilutus in 10-d bioassays, and the potential toxicants were assessed using TIE in these sediments after dilution. The results of phase I characterization showed that organic contaminants were the principal contributors to the mortality of the midges in 2 sediments and that metals and organics jointly caused the mortality in the other 2 sediments. Ammonia played no role in the mortality for any samples. Conventional toxic unit analysis in phase II testing identified Cr, Cu, Ni, Pb, and Zn as the toxic metals, with cypermethrin, lambda-cyhalothrin, deltamethrin, and fipronils being the toxic organics. To improve the accuracy of identifying the toxicants, 4-step sequential extraction and Tenax extraction were conducted to analyze the bioavailability of the metals and organics, respectively. Bioavailable toxic unit analysis narrowed the list of toxic contributors, and the putative toxicants included 3 metals (Zn, Ni, and Pb) and 3 pesticides (cypermethrin, lambda-cyhalothrin, and fipronils). Metals contributed to the mortality in all sediments, but sediment dilution reduced the toxicity and confounded the characterization of toxicity contribution from metals in 2 sediments in phase I. Incorporating bioavailability-based measurements into whole-sediment TIE improved the accuracy of identifying the causative toxicants in urban waterways where multiple stressors occurred and contributed to sediment toxicity jointly. Environ Toxicol Chem 2015;34:1744-1750. © 2015 SETAC [ABSTRACT FROM AUTHOR]

CO sequestration in deep saline formations has been proved to be an effective method for reducing greenhouse emissions into the atmosphere. However, pure sequestration of CO will add to the costs incurred by both industries and governments. A win-win method of CO injection and hot brine (water) extraction can become attractive to the investors, as it will not only increase the storage capacity of the injected CO, but also offset the costs by selling and using the produced hot water for industrial, agricultural or household purposes. For instance, water from very hot geothermal reservoirs ( T ≥ 150 °C) can be used for electricity generation in power plants and water from low-medium temperature reservoirs, the most predominant in natural systems, are more popular for direct use, e.g., in heating systems, household hot water, baths, aquaculture, etc. In this paper, low-medium geothermal reservoirs widely distributed in China, especially those in the Ordos Basin, were selected for the numerical case studies using TOUGH2MP with the ECO2N module for the simulations. Generally, simulation parameters were taken from the Ordos Basin, where the first full-integration CO sequestration project had been operated since 2010. The simulations in the base case study lasted 35 years, based on the lifespan of a normal geothermal project. Shallow re-injection systems were also considered to investigate the influence of thermal breakthrough, pressure perturbation, etc. Results show that injection of cold CO causes sharp decrease in temperature in the reservoir region near the injection well, which is enlarged with continuous injection. The region near the production well is dominated by different fluid phases during the CO driven process, including a single water phase, a two-phase fluid (water and CO) and a phase of almost pure CO. Results also show that the CO breakthrough lags far behind the pressure response in the geothermal production system. Before breakthrough, the injected CO pressurizes the reservoir, improving the overall performance of the geothermal reservoir. Furthermore, the heat extraction efficiency of CO-based system is obviously higher than HO-based system. [ABSTRACT FROM AUTHOR]

A sequential extraction procedure was applied to determine the concentration and fractionation characteristics of eight heavy metals (HMs) (Cu, Zn, Pb, Cd, Cr, Fe, Mn, and Ni) in a sediment core collected from the old Yellow River Estuary, China. The results revealed that the mean deposition rate of this sediment core, which spanned 87 yr (1925-2012), was approximately 0.5 cm yr-1. The mean concentrations and ranges of HMs were Cu: 26.9 (18.3-38.5), Zn: 76.4 (51.0-107), Pb: 37.3 (1 7.8-53.8), Cd: 0.23 (0.20-0.27), Cr: 84.7 (45.5-116), Fe: 24,000 (16,500-31,700), Mn: 709 (388-1020), and Ni: 36.1 (24.8-47.2) mg kg-1 (dry weight). Six HMs (Cu, Zn, Cr, Cd, Fe, and Ni) were present in their highest proportion in the residual fraction; their lowest proportion was observed in the exchangeable fraction. Lead primarily existed in the oxidizable or residual fraction. Manganese was mainly presented in the exchangeable fraction.The riskassessment code results revealed that the sediments displayed a low risk for Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni. The HMs Cu, Zn, Cr, Cd, Mn, and Ni displayed minor enrichment in the sediment core, whereas for Pb, moderate contamination enrichment was observed. Overall, an increase in /geo and total concentration of HMs occurred since 1925 and reached a maximum value around 1980, after which there was a larger fluctuation or decline until 2012. We also found that the degree of HM pollution during the 1976-1996 period was less serious than before 1976. All the sediment samples exceeded the effect range low (ERL) for Ni, whereas 56.1, 7.32, and 17.1% exceeded the ERL values for Cr, Cu, and Pb; no samples exceeded the ERL for Zn or Cd. [ABSTRACT FROM AUTHOR]

A total of 271 sediments samples from the Zhalong Wetland were analyzed for concentration and distribution of Hg, Cd, As, Cu, Pb, Zn, Cr, and Zn; their speciation according to the modified European Community Bureau of Reference sequential extraction procedures and their ecological risk based on Lars Hakanson's potential ecological risk assessment and risk assessment code were made. The results can be summarized as the followings: (1) Concentrations of all metals measured were above soil background values of Songnen Plain, and their spatial distributions were distinctly different. The concentrations of metals (except Pb) were high in the east, followed by the north, and were relatively low in the core zone and south. The concentration of Pb was high in the north, south, and west, compared with low concentration in the core zone and east. (2) The dominant proportion of Pb, Zn, and Cr was in the residual fraction, suggesting that they were environmental stable. The concentrations of Cu and As in the reducible fraction, the concentration of Cd in the acid-soluble fraction, and the concentration of Hg in the oxidizable fraction were relatively high, indicating they had greater environmental effects. (3) The evaluation of the ecological risk showed that Cd, Hg, and As had relatively high ecological risk index, especially the ecological risk of Cd should be paid attention to. In general, the ecological risk of the heavy metals and metalloid by zone was experimental zone > buffering zone > ecological tourism zone > core zone. [ABSTRACT FROM AUTHOR]

The concentrations of different phosphorus (P) species and four kinds of bioavailable P (algae-available P, AAP; Olsen P, OLP; water-soluble P, WSP; and readily desorbable P, RDP) were determined to investigate the relationship between phosphorus bioavailability and phosphorus speciation in sediments from rural rivers in Taihu Lake area, China, using a European Commission "Standards Measurements and Testing Program" protocol and four chemical extraction techniques. The total P and inorganic P concentrations in the sediments were 179-2,293 mg/kg and 137-1,857 mg/kg, respectively. The concentrations of the P species in the sediments followed the order NaOH- extractable P > HCl-extractable P > organic P. The bioavailable P concentrations followed the order AAP (340 mg/kg) > OLP (38.7 mg/kg) > WSP (1.8 mg/kg) > RDP (0.3 mg/kg). Regression analyses showed that there were good correlations between the P species concentrations and the bioavailable P concentrations measured using the four different methods, except for between WSP and the HCl-extractable P concentrations. The OLP concentrations had highly significant correlations with AAP, WSP, RDP and the P species concentrations. The OLP method was found to be most suitable for determining the bioavailability of P species under the prevalent geochemical conditions in the rural river sediments that were analyzed. [ABSTRACT FROM AUTHOR]

Hyperlink extraction technology, by virtue of its remarkable advantage of decreasing the use of chemicals in multi-component separation, has been extensively employed in rare earth separation industry in China. In hyperlink processes, non-barren extracting solvent and scrubbing agent solution which contain the component(s) involved in starting feed are employed in order to save both alkali for saponification and acid for scrubbing. Minimum amount of extracting solvent (denoted as Smin) and that of scrubbing agent solution (denoted as Wmin) are important parameters to determine the consumption amounts of alkali and acid for a given countercurrent extraction separation. This article therefore discusses the influence of using non-barren extracting solvent and scrubbing agent solution on Smin and Wmin of an (A1A2···A t−1)/(A2A3···A t) separation. The equations for Smin and Wmin are derived, and the variation of the composition of final raffinate as well as that of final extract are determined, which will provide a valuable guidance for the design of hyperlink extraction processes of multi-component separation, such as rare earths separation. [ABSTRACT FROM AUTHOR]

Abstract: The optically stimulated luminescence (OSL) signals from quartz have been widely used to estimate the equivalent dose (D e) of environment radiation after the deposition of mineral grains. However, the usage of quartz is often limited due to the lower saturation behavior compared with feldspar. Saturation limits among quartz (defining the upper dating range) vary significantly. It is important to better understand the reason for various dose saturation behaviors of the quartz OSL signals. In this study, coarse quartz grains were extracted from the Taklimakan Desert and the Hunshandake sandy land in north China and the dose saturation behavior of quartz OSL signals were studied. Our results suggest that the quartz grains produce very different aliquot-specific dose response curves, showing the significant variability in dose saturation characteristics for OSL signals. Laboratory dosing, optical bleaching and heating experiments were designed to simulate their effects on the dose saturation behavior for the quartz OSL. The results demonstrate that cycles of dosing and optical bleaching have insignificant impact on the OSL dose growth curves, while the heating to high temperature (above 400 °C) can significantly change the dose saturation characteristics for the quartz OSL. Such results suggest that the different heating history of quartz might be an important factor for the variability in dose saturation characteristics for OSL signals. Additionally, the quartz grains from the Hunshandake sandy land exhibit lower dose saturation level for OSL signals, compared with that from the Taklimakan Desert. This can be explained that the quartz grains from Hunshandake sandy land are mainly of igneous origin, while the quartz grains from Taklimakan Desert are mainly of metamorphic origin. [Copyright &y& Elsevier]

Context: Securidaca inappendiculata Hassk. (SI) is used to cure fractures and rheumatoid arthritis in China. Also, it is a potential antidiabetes drug; however, there are no reports on this. Objective: The study was designed to evaluate the antihyperglycemic activities of fractions and compounds from SI, and attempt to explore the mechanism. Materials and methods: Antihyperglycemic activities were evaluated by the suppression on serum glucose levels in vivo and α-glucosidase inhibition assays in vitro. Fractions were given to mice by gastric intubation for 8 d. The high, medium, and low doses of fractions were equal to 10, 5, and 2.5 g/kg of the herb [SID (dichloromethane fraction) and SIE (ethyl acetate fraction) were doubled]. The serum glucose was monitored at 1 and 12 h after feeding. The silica gel and LH-20 chromatography were used to isolate active compounds. Structure-activity relationship analysis was based on IC50s and structures. Results: The IC50s of SID, SIE, SIA (acetone fraction), SIM (methanol fraction), and acarbose were 712, 446, 1123, 1418, and 735 μg/mL. The postprandial and fasting serum glucose levels of SID, SIE, SIA, and SIM (high dose) were 5.5, 5.9, 6.2, 6.3 and 3.7, 3.5, 4.0, 5.0 mmol/L, while those of vehicle control were 7.5 and 5.6 mmol/L. Eleven xanthones isolated all exhibited inhibitory activities, mainly in a non-competitive reversible manner. The IC50s varied from 3.2 to 77.3 μg/mL. Structure-activity relationship analysis exhibited free hydroxyls contributed the most importance to the activity. Conclusion: The results indicated that xanthones from SI were powerful agents for antidiabetes. [ABSTRACT FROM AUTHOR]

Abstract: Red pigments extracted from fungus Monascus are used for food coloration in China. Wild-growing Monascus spores are usually enriched in the yeast and mold media in the air, but those media are also favorable for yeast and bacteria. In the paper, Monascus species have grown in retrograded maize starch lain in air outdoors in winter, molds, yeast or bacteria colonies have been absent. Then a medium of the retrograded maize starch for enriching Monascus in the air is explored and its physicochemical properties are determined by ordinary camera photos, NMR, SEM spectra and X-ray diffraction. The lamellar structure of frozen retrograded maize starch, whose interlamellar spacing is about 2μm, provides a favorable condition for Monascus spore to germinate and grow. [Copyright &y& Elsevier]

The first global night-time light composite data from the Visible Infrared Imaging Radiometer Suite (VIIRS) day–night band carried by the Suomi National Polar-orbiting Partnership (NPP) satellite were released recently. So far, few studies have been conducted to assess the ability of NPP-VIIRS night-time light composite data to extract built-up urban areas. This letter aims to evaluate the potential of this new-generation night-time light data for extracting urban areas and compares the results with Defense Meteorological Satellite Program–Operational Linescan System (DMSP-OLS) data through a case study of 12 cities in China. The built-up urban areas of 12 cities are extracted from NPP-VIIRS and DMSP-OLS data by using statistical data from government as reference. The urban areas classified from Landsat 8 data are used as ground truth to evaluate the spatial accuracy. The results show the built-up urban areas extracted from NPP-VIIRS data have higher spatial accuracies than those from DMSP-OLS data for all the 12 cities. These improvements are due to the relatively high spatial resolution and wide radiometric detection range of NPP-VIIRS data. This study reveals that NPP-VIIRS night-time light composite data would provide a powerful tool for urban built-up area extraction at national or regional scale. [ABSTRACT FROM PUBLISHER]

Abstract: Life cycle assessment was conducted to estimate the environmental impact of caustic soda production. Electricity and raw salt production accounted for >90% of the overall environmental burden. These findings can be attributed to electrical consumption for bipolar electrolysis and brine extraction, diesel consumption for generating electricity during well production, and direct heavy metal emissions during drilling fluid loss and waste disposal. The key factors in reducing the overall environmental impact include optimizing raw salt production, electricity, and steam consumption efficiency, choosing drilling fluids with less toxic heavy metals (e.g., arsenic, barium, molybdenum, selenium, vanadium, beryllium, and nickel), minimizing brine leakage during brine transport, reducing the volume of drilling fluid lost, and decreasing the transport distance from brine buyers to suppliers. [Copyright &y& Elsevier]

Highlights: [•] The fractionation behavior of trace element was determined by sequential extraction. [•] The selected trace elements are mainly associated with sulfide minerals. [•] The trace element in coal gangue may lead to potential environmental risks. [ABSTRACT FROM AUTHOR]

Abstract: Because phosphorus (P) is a vital biogenic element for aquatic ecosystems, a deeper understanding for the turnover of P in lake sediments is much needed. In this study, seven lakes representing major lake types in the Eastern Plain region of China were selected so to identify and quantify the characteristics and lability of sediment P. A relatively new approach called Phosphorus-31 nuclear magnetic resonance spectroscopy (31P NMR) was adopted to detect the different P species in the lake sediments. The experimental results indicate that NaOH–EDTA extraction by 31P NMR analysis is a useful technique for determining and measuring each P compound in the studied shallow lake sediments. Orthophosphate, orthophosphate monoesters and orthophosphate diester are identified as the major chemical forms of phosphorus in the sediments. There is a greater content of these compounds in the sediments of the highly polluted lakes than the less-polluted lakes. Moreover, the content of orthophosphate, orthophosphate monoesters and orthophosphate diester (sediment) is in proportion to the total P and Chla (chlorophyll a) (overlying water) in the lakes of the Eastern Plain, indicating their potential bioavailability. This positive correlation also implies that the role organic P plays in lake eutrophication should be given more attention, particularly for the heavily polluted sediments. Finally, a significant correlation exists between APA and TP and IP in the Eastern Plain lake region. A possible hydrolytic pathway for the various organic phosphorus compounds by APA is also discussed. [Copyright &y& Elsevier]

[Objective] The study aimed to develop the forecasting and early warning system of floods in small and middle river basins. [Method] Taking small and middle rivers in Jiangxi Province as the research object, using the Hydro ArcTools module of arcgisl 0, the digital drainage network and basin boundaries of Jiangxi Province were extracted from the 1:50 000 digital elevation model (DEM) of Jiangxi Province. Afterwards, the geographic information database of small and middle rivers were established, and areal precipitation in Chongyi region was calculated using Thiessen polygon method based on precipitation data during June 20-22, 2012. [Result] When the threshold was 78 655, the extracted river systems and basin boundaries could meet the demand of actual application and could be used as the basic parameters of areal precipitation prediction model. The areal precipitation in Chongyi region was higher than 7 mm, and it was higher in the east compared with the west. [Conclusion] The research could provide scientific references for the control and prevention of flood in future. [ABSTRACT FROM AUTHOR]

An improved analytical method is reported for the determination of six aflatoxins (aflatoxins B1, B2, G1, G2, M1, and M2) in infant cereals by ultra-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry in the multiple reaction monitoring mode. The optimization of extraction, cleanup, separation, and mass spectrometry parameters were the focus of this study. Low limits of quantification (LOQs) of six aflatoxins ranged from 0.004–0.026 µg/kg. Reasonable recoveries (80.7–118.3%) of six aflatoxins for infant cereals were demonstrated for different spiked levels within the linear range (0.01–20 µg/kg). The developed analytical method was employed for the determination of aflatoxins in infant cereals from Hangzhou, China. Only aflatoxin B1 was detected in cereal (6.7%), at levels ranging from 0.016 to 0.024 µg/kg. [ABSTRACT FROM AUTHOR]

Abstract: The concentrations of Cu, Pb, Zn and Cd were measured in water and sediment to determine their distribution characteristics and potential ecological risks of the Lake Dalinouer. The results revealed that the dominate form of Cu, Pb, Cd and Zn in surface sediments respectively were organic sulfides, Fe–Mn oxides, carbonates and Fe–Mn oxides, with a mean content of 4.28mgkg−1, 0.76mgkg−1, 7.84μgkg−1 and 1.77mgkg−1, respectively; the concentrations of bio-available metals had an increase tendency from the northeast to the southwest part of this lake. Acid volatile sulfides (AVS) and simultaneously extracted metal (SEM) were used to predict the potential bioavailability of heavy metals. The horizontal distribution of AVS (0.15–2.4μmolg−1, mean 0.53μmolg−1) in surface sediments shows an increasing trend from southwest to northeast of the lake, whereas SEM (0.02–0.99μmolg−1, mean 0.37μmolg−1) had an opposite pattern. The relative high salt and pH which restrained the bioactivities of sulfate-reducing bacteria (SRB) were the main controlling factor in AVS concentrations. The vertical variation of AVS concentration in sediment core increased with depth and different from SEM. Potential ecological risk index (PERI) and geo-accumulation index (Igeo) were used to assess heavy metals accumulation. The results indicated that moderate contamination of most heavy metals was prevalent and presented a decreased trend from southern to northern of the lake, and element Cd emerged the greatest potential ecological risk. The pollution of heavy metal in the southern of the Lake Dalinouer should be taken into consideration seriously. [Copyright &y& Elsevier]

Abstract: The lower Liaohe River Plain (LRP) is an economically and ecologically important area situated on an alluvial plain, where anthropogenic activities are very intensive. Field investigations were conducted in the LRP and 15 water quality parameters surveyed at 216 wells during September and October of 2009 and 2010. These showed significant variation in the hydrochemistry of groundwater throughout the plain. A Piper plot was used to identify the major geochemical processes occurring in the entire plain. Principal components analysis (PCA) was used to identify various underlying natural and anthropogenic processes that created these distinct water types. The Stuyfzand classification was used to subdivide and interpret the complex groundwater hydrochemistry of the Liaohe River delta. Five principal components (PCs) were extracted in terms of PCA, which can be invoked to explain 82% of the total variance in water quality parameters. The PCA results can be categorized by five major factors: (1) Holocene transgression and mixing; (2) surface water infiltration; (3) multi-factor processes; (4) rainfall and agricultural fertilizer contamination; and (5) Geogenic F enrichment. This study demonstrates that the great variation of groundwater hydrochemistry in the LRP should be attributed to both natural and anthropogenic processes. [Copyright &y& Elsevier]

Abstract: A method has been developed for speciation analysis of ultra low level 129I in soil using sequential extraction combined with coprecipitation for separation of carrier free iodine and AMS measurement of 129I. Two loess profiles collected from northwest China were analyzed for species of 129I and 127I. Similar partitioning of 129I and 127I was observed in the loess profiles, the distribution of iodine isotopes followed an order of organic > leachable > reducible > residue. The 129I concentrations and 129I/127I ratios decreased exponentially with the depth, and 2 orders of magnitude lower in the deepest layer (60 and 90 cm) compared with the top layer, indicating a significant contribution of anthropogenic input in the upper layer, and high retention of 129I in soil. The mobility of 129I in different fractions decreased in an order of leachable > organic > oxides > residue. The results suggest that migration of iodine downwards in the soil profile is a slow process; the oxides and residue are the less mobile fractions of iodine. [Copyright &y& Elsevier]

Abstract: Environmental pollution due to mining activities has been reported in many countries. In this study, 283 vegetable and 44 corresponding garden soil samples were collected in the vicinity of the Tongling mining area, China. The aim was to evaluate the bioavailability of trace metals (Cu, Zn, Pb and Cd) to vegetables by comparing different methods (trace metals in DTPA, EDTA, HCl, NH4NO3, NH4OAC aqueous solutions and total metals in garden soils), and assess the potential health risks of trace metals to the local population via vegetable consumption. The results showed that the mean values of total Cu and Cd in the soil samples exceeded the Grade II national standard in China. Average concentrations of Cd and Pb in some vegetable samples were higher than the maximum permissible concentration in China. The transfer factors for trace metals in different vegetables showed a trend of Cd>Zn>Cu> Pb. Asteraceae vegetables had stronger metal uptake than Liliaceae. The total target hazard quotient (THQ) value was greater than 1, suggesting that trace metals in vegetables could present some potential health risks. The effectiveness of the studied methods for estimating soil metal bioavailability was generally dependent on the particular metal and vegetable species. Overall, 1.0M NH4OAC provided the best estimate of Cd and Zn bioavailability in multi-elemental contaminated soils. None of the studied soil metal extraction methods appeared suitable for measuring Cu or Pb bioavailability, especially for Pb, which showed almost no correlation between metal concentration in soil and vegetables. [Copyright &y& Elsevier]

In this paper, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in biota (reed, grass, mussel, fish, and red-crowned crane) and sediments collected from seven locations in the Zha Long Wetland. PAHs were recovered from the sediments and biota by ultrasonic extraction and then analyzed by means of gas chromatography-mass spectrometry. The total PAH concentrations were 244-713 ng/g dw in sediments, 82.8-415 ng/g dw in plants and 207-4,780 ng/g dw in animals. The total sediment PAH concentrations were categorized as lower to moderate contamination compared with other regions of China and the world. In the plant samples, the accumulation abilities of reed roots and stems for PAHs were higher than those of grass roots. In addition, the concentration of individual PAHs in mussel muscles was the highest in all of the animal samples, followed by fish, feeding crane fetuses, and wild crane fetuses. Compositional analysis suggests that the PAHs in the sediments from the Zha Long Wetland were derived from incomplete biomass combustion. Risk assessment shows that the levels of PAHs in sediments are mostly lower than the effects range mean value (effects range mean), whereas only naphthalene in all sample sites was higher than the effects range low value. It is worthwhile to note that benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene and benzo(ghi)perylene were detected in crane fetal, which have potential carcinogenicity for organisms from the Zha Long Wetland. [ABSTRACT FROM AUTHOR]

The Permian Dalong Formation (P d) source rocks from the mature Guangyuan outcrop section and the overmature Wangcang outcrop section in Sichuan Basin were selected. The Soxhlet extraction and kerogen catalytic HyPy were conducted on the P d source rocks. The biomarkers obtained by both methods were compared to discuss their difference and the influence extent of thermal maturation on covalently bound biomarkers. The results show that covalently bound biomarkers can hardly be correlated to the corresponding free biomarkers due to severe thermal alterations and/or interference of migrated hydrocarbons in both outcrop sections and thermal maturation have much lower influence on covalently bound biomarkers in kerogens than on free biomarkers in Soxhlet extracts. The application of HyPy in study of biomarker geochemistry can reduce the thermal maturation effect on biomarkers ( R⩾2.4%) to a greater extent and the interference of migrated hydrocarbons between interbedded layers. The covalently bound biomarkers released by HyPy are useful in the study of biomarker geochemistry and oil-source correlation on high-overmature source rocks. [ABSTRACT FROM AUTHOR]

Abstract: In this study, an aqueous ionic liquid based ultrasonic assisted extraction (ILUAE) method for the extraction of the four acetophenones, namely 4-hydroxyacetophenone (1), 2,5-dihydroxyacetophenone (2), baishouwubenzophenone (3) and 2,4-dihydroxyacetophenone (4) from the Chinese medicinal plant Cynanchum bungei was developed. Three kinds of aqueous l-alkyl-3-methylimidazolium ionic liquids with different anion and alkyl chain were investigated. The results indicated that ionic liquids (ILs) showed remarkable effects on the extraction efficiency of acetophenones. In addition, the ILUAE, including several ultrasonic parameters, such as the ILs concentration, solvent to solid ratio, power, particle size, temperature, and extraction time have been optimized. Under these optimal conditions (e.g., with 0.6M [C4MIM]BF4, solvent to solid ratio of 35:1, power of 175W, particle size of 60–80 mesh, temperature of 25°C and time of 50min), this approach gained the highest extraction yields of four acetophenones 286.15, 21.65, 632.58 and 205.38μg/g, respectively. The proposed approach has been evaluated by comparison with the conventional heat-reflux extraction (HRE) and regular UAE. The results indicated that ILUAE is an alternative method for extracting acetophenones from C. bungei. [Copyright &y& Elsevier]

Abstract: Eclipta prostrata L., (Asteraceae), is used in China for both food and medicine purposes. This research is concerned with the isolation and purification of phytochemical constituents from the aerial parts of E. prostrata, using gradient solvent fractionation, macroporous resin, silica gel, Sephadex LH-20 and ODS columns, and TLC analyses. Four fractions (water, 30% ethanol, 60% ethanol and 90% ethanol) were obtained. Four compounds, wedelolactone (I), eclalbasaponin I (II), luteolin (III) and luteolin-7-O-glucoside (IV) were purified and their structures were identified by the interpretation of spectroscopic analyses including MS, 1H and 13C NMR. Antitumor activities of extracts (total fraction), four fractions and the isolated compounds were assessed using hepatoma cell smmc-7721 as an in vitro assay system. The 30% ethanol fraction and eclalbasaponin I dose-dependently inhibited the proliferation of hepatoma cell smmc-7721 with IC50 values of 74.2399 and 111.1703μg/ml, respectively, more strongly compared with 5-fluorouracil positive control group with the IC50 value of 195.3131μg/ml. Antitumor activities of other fractions and compounds were lower than positive control. These results suggested that some specific compounds or extracts from E. prostrata are potential sources of natural anti-tumor materials and worthy of further study. [Copyright &y& Elsevier]

Abstract: In this work, the remediation of soils contaminated with multiple metals using ferric and alum water treatment residuals (FARs) in Baiyin, China, was investigated. The results of metals fractionation indicated that after the soil was treated with FARs, arsenic (As), lead (Pb), nickel (Ni), zinc (Zn) and copper (Cu) could be transformed into more stable forms, i.e., As bound in crystalline Fe/Al oxides and other metals in the oxidable and residual forms. However, the forms of chromium (Cr) and cadmium (Cd) were unaffected. Interestingly, due to the effect of FARs, barium (Ba) was predominantly transformed into more mobile forms. The bioaccessibility extraction test demonstrated that the FARs reduced the bioaccessibility of As by 25%, followed by Cu, Cr, Zn, Ni and Pb. The bioaccessibility of Cd and Ba were increased; in particular, there was an increase of 41% for Ba at the end of the test. In conclusion, the FARs can be used to remedy soil contaminated with multiple metals, but comprehensive studies are needed before practical applications of this work. [Copyright &y& Elsevier]

Extraction of Xinjiang oil sand by the series of YSFL oil sand separation agents was studied. In the extraction experiment, the effect of the agent concentration, reaction temperature, and heating time have been studied. The optimal condition was confirmed. When the agent concentration was 7%, the heating time was 30 minutes, and when the temperature was 85°C, the bitumen production rate could reach more than 95%. The agent after separation can be cycle-utilized for the environment-friendly property. [ABSTRACT FROM PUBLISHER]

There are few researches on the characteristics of phosphorus (P) in the newly born wetland soils from Yellow River Delta of China. Meanwhile, whether the wetland soils can protect the aquatic ecosystem from excessive P input or not and the risk of P release from the soils to the water quality have generated considerable interests. Through isothermal batch static equilibrium sorption experiments followed by six subsequent extraction steps, the present study assessed the variations in P sorption and desorption properties of the newly born wetland soils in Yellow River Delta. It is found that the P sorption isotherms were nonlinear and the amount of P sorption reached a steady state as P initial concentration added increased in the studied soils. Though the capacity of P retention differed strongly among the studied zone, the soils can protect the aquatic ecosystem from excessive P input to a certain extent degree. From the desorption experiments, it is found that the newly sorbed P was easily desorbed in higher initial added concentration and the desorption P significantly decreased with successive extraction in all samples. The release of P from soil proposed a significant contribution to the water quality and eutrophication of coastal zone. Correlation and regression analyses showed that the amorphous and free Fe/Al oxides, correlated with clay content in the studied soils, were the crucial chemical factors ascribed to the soil P retention and release capacity. [ABSTRACT FROM AUTHOR]

Three different isolation techniques, specifically microwave-assisted hydrodistillation (MAHD), ultrasound-assisted extraction (UAE), and conventional hydrodistillation (HD) were employed to obtain essential oils from whole plants, leaves, roots, and stems of Perilla frutescens. The essential oils were analyzed using gas chromatography with flame ionization detection and gas chromatography with mass spectrometry. Variations in chemical composition were observed; these were attributed to differences in plant organs. Variations in the percentages of the main constituents of the oils extracted based on plant organ were irregular and affected the quantity and composition of the oils. Oil yields were affected by the method of extraction and extraction organ variation. The maximum volume of oil was extracted from leaves via MAHD and the minimum was extracted from roots via UAE. Oil yields ranged from 0.05% to 0.53%. The contents of essential oil varied significantly with the plant organ. In the essential oils of the plant parts studied were showed a predominance of oxygenated monoterpenes. Variation of extraction methods and organs may influence the oil components either qualitatively or quantitatively. [ABSTRACT FROM PUBLISHER]

Abstract: Upland and paddy soils, as well as corn samples, were collected in the selenosis area of Naore Village, Ziyang County, Shaanxi Province, China. A five-step sequential extraction procedure was used for selenium (Se) fractionation, including soluble Se, exchangeable Se and carbonate-bound Se, iron and manganese oxide-bound Se, organic matter-bound Se, and the residual Se fraction. Species of soluble Se in upland soils included Se−2, Se4+, and Se6+. The results showed that soluble Se and exchangeable Se fractions accounted for less than 1% of the total Se in the upland soil, but approximately 16.1% in the paddy soil. Concentrations of residual Se were lower than those of iron and manganese oxide-bound Se and organic matter-bound Se in both upland and paddy soils. Iron- and manganese oxide-bound Se was the dominant fractions in upland soil, whereas organic matter-bound Se abounded in paddy soil. Concentrations (mgkg−1) of Se in the corn samples ranged from 0.05 to 14.5 in seed, 0.31 to 12.3in root, 0.09 to 9.15 in stalk, and 0.16 to 36.15 in leaf. Path analysis indicated that soluble Se6+ significantly (P <0.05) affected Se accumulation in corn tissues directly, whereas the organic matter-bound Se had a significant (P <0.05) indirect effect. In conclusion, corn did not readily absorb a major portion of soil Se. However, organic matter-bound Se was an important fraction and source of plant Se in agricultural soil. [Copyright &y& Elsevier]

ABSTRACT To investigate the variations of flavor substances in distillation process of Chinese Luzhou-flavor liquor, systematic experiments were carried out in an industrial-scale experimental distiller. Distillate samples were collected continuously throughout the whole distillation process and analyzed by gas chromatography and sensory evaluation. The results show that the compositions and variations of flavor substances mainly depend on their physical and chemical properties. The flavor substances with low boiling point, such as ethanol, acetaldehyde, ethyl format and ethyl acetate, are vaporized quickly and therefore have high contents in the distillate obtained in the early stage of distillation. The flavor substances with high boiling points enter into distillate mainly by extraction and, hence, their variations depend on the dissolving properties. The alcohol-soluble substances, such as ethyl hexanoate, ethyl butanoic and so on, are distilled out mainly in the early stage of distillation, and their extraction rates decrease as the distillation process proceeds, while the water-soluble substances, such as organic acids, ethyl lactate and so on, are mainly present in the latter-stage distillate and the extraction rates increase as the process proceeds. Variations of methanol and furfural were found irregular and the reasons for this irregularity were analyzed. Sensory quality of distillate declines as the distillation process proceeds. PRACTICAL APPLICATIONS Chinese liquor has been a traditional art continuing for thousands of years, but the distillation operation almost holds its way of ancient time and few studies about it have been conducted, so that the understanding of distillation process is largely limited to intuition. Variations of flavor substances during distillation process will certainly contribute to the understanding of distillation mechanism and the optimization of distillation operation. The remarkable differences of distillate qualities found in different distillation stages provide an experimental base for collecting liquors with different distillate qualities. The findings that the high quality distillate is produced in early distillation stage indicate the necessity to overcome the vapor-overflow phenomenon, which occurs usually in the early stage of distillation and causes a lot of loss of high quality liquor. Theoretically, this work will provide the experimental base and testifying data for the modeling of multicomponents mass transfer in liquor distillation process through a packed bed. [ABSTRACT FROM AUTHOR]

In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated, respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is followed in decreasing order by the organic matter-bound, Fe-Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore, both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate. [ABSTRACT FROM AUTHOR]

Lead (Pb) contents and partition in soils collected from eleven vegetable-growing lands in Fujian Province, China, were investigated using a modification of the BCR (Community Bureau of Reference) sequential extraction procedure coupled with the Pb isotope ratio technique. Pb contents in Chinese white cabbage ( B. Chinensis L.) grown on the lands for this study were also measured. Results showed that Pb concentrations in fifty samples of topsoil ranged from 456 to 21.5 mg kg, with each mean concentration of six sampling lands exceeding the national standard (50 mg kg); while Pb concentrations in edible portions of thirty-two vegetable samples ranged from 0.009 to 2.20 mg kg, with four sampling sites exceeding the national sanitary standard (0.2 mg kg). A significant correlation ( r = 0.971, P < 0.01) of Pb contents in the acid-extractable fractions by BCR approach and the vegetables was observed, which indicates that the acid-extractable Pb is useful for evaluating the metal bioavailability for plants and potential risk for human health in soils. The determination of lead isotope ratios in different chemical forms of soils by BCR sequential extraction procedures provides useful information on the Pb isotopic composition associated with different soil fractions (especially in the acid-extractable fractions), and the result is helpful for the further study on controlling and reducing Pb contamination in vegetable-growing soils. [ABSTRACT FROM AUTHOR]

Abstract: Arsenic is a highly toxic metalloid and has posed high risk to the environment. As(III) is highly mobile in soil and leached easily into groundwater. The current remediation techniques are not sufficient to immobilize this toxic element. In the present study, an As(III) tolerant bacterium Sporosarcina ginsengisoli CR5 was isolated from As contaminated soil of Urumqi, China. We investigated the role of microbial calcite precipitated by this bacterium to remediate soil contaminated with As(III). The bacterium was able to grow at high As(III) concentration of 50mM. In order to obtain arsenic distribution pattern, five stage soil sequential extraction was carried out. Arsenic mobility was found to significantly decrease in the exchangeable fraction of soil and subsequently the arsenic concentration was markedly increased in carbonated fraction after bioremediation. Microbially induced calcite precipitation (MICP) process in bioremediation was further confirmed by ATR-FTIR and XRD analyses. XRD spectra showed presence of various biomineralization products such as calcite, gwihabaite, aragonite and vaterite in bioremediated soil samples. The results from this study have implications that MICP based bioremediation by S. ginsengisoli is a viable, environmental friendly technology for remediation of the arsenic contaminated sites. [Copyright &y& Elsevier]

Abstract: Species and bioavailability of phosphorus in surface sediments from the middle and lower reaches of the Yellow River were investigated using the sequential extraction method. Sedimentary inorganic phosphorus were fractioned into four forms and the rank order according to the mean concentration of P-fraction in Yellow river was HCl-P > NaOH-P > BD-P > NH4Cl-P. The linear relationship between the sum of BD-P and NaOH-P and the sum of active Fe and active Al content was observed within the twelve sediments investigated (R2=0.66). Moreover, the bio-available phosphorus (BAP) content was estimated by the sum of NH4Cl-P, BD-P, and NaOH-P, viz. BAP = NH4Cl-P + BD-P + NaOH-P. In Yellow River, the BAP contents were ranging from 0.031 mg/g dw (dry weight) to 0.066 mg/g dw, and average 0.050 mg/g dw for all sediment samples. The relative contributions of BAP to inorganic sedimentary phosphorus (IP) range from 41% to 62% (53% on average). [Copyright &y& Elsevier]

Abstract: Estrogens (estrone, estradiol and estriol) and synthetic compound (ethynyl estradiol) in the water and sediment of Licun River-Jiaozhou Bay area in Qingdao were monitored. Estrogens in waters were concentrated using modified C- 18 SPE cartridges, and estrogens in sediments were extracted by liquid-solid extraction. Silane derivatives of the extracted and concentrated estrogens were analyzed by GC-MS. The concentration of estrogens ranged from ND (below the detection limit) to 180ng/L in waters and ND to 10.8colong/kg (dry weight) in sediment. The concentrations of estrogen in river water were higher than those in seawater during the monitoring periods. The distribution of estrogen concentration along Licun river suggested that estrogens were different with distance from the respective effluent sites. The highest concentrations were detected at station 5 which directly receives huge quantities of pollutants from adjacent rivers containing large amounts of farming and industrial wastewater. [Copyright &y& Elsevier]