Environmental Chemistry

ISSN 0254-6108

CN 11-1844/X

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Degradation of perfluorooctanoic in water using gas-liquid pulsed discharge plasma
HU Yuqing, SONG Wenzhe, MA Chunmeng, YU Jianwei, SHANG Wei, YANG Min, ZHANG Yu
2019, 38(10): 2171-2179.   doi: 10.7524/j.issn.0254-6108.2018112905
Abstract PDF 5660KB
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Perfluorinated compounds in water have strong stability and are difficult to be removed by conventional methods. In this study, perfluorooctanoic acid (PFOA) was used as the target, to investigate the influence factors and the removal efficiency of PFOA using gas-liquid pulsed discharge plasma reactor based on droplet spray, and the removal mechanism was also discussed. It was found that when the initial concentration of PFOA was 1.5 μg·L-1, the plasma pulse frequency was 1000 pps, and the voltage was 25 kV, the removal rate of PFOA reached 40.5% after 2 hours. By comparing the removal efficiency under different instrumental parameters, it was found that PFOA removal efficiency was higher under low pulse frequency and low voltage conditions. The k/PD value of the removal efficiency was 0.259 L·min-1·W-1, which was higher than the maximum k/PD value of the laminar jet with bubbling reactor reported at the same concentration level (0.025 L·min-1·W-1), showing that the energy consumption of the droplet spray reactor was low. A variety of short-chain perfluorocarboxylic acids and F- were detected in the process of plasma treatment. The total production of short-chain perfluorocarboxylic acids produced after 2 hours accounted for about 10% of the initial PFOA. The removal of PFOA was significantly inhibited after the addition of the electronic inhibitor NaNO3, indicating that free electrons play a major role in the initial reaction process. It provides a promising technical method for the effective removal of PFOA in water.
Synthesis of bimetallic Fe0-Cu0 to catalyze persulfate for degradation of dibutyl phthalate
LOU Luoqi, CHEN Jiale, ZHANG Jian, YAO Yuzhe, MIAO Xiangrui, LI Huanxuan
2019, 38(10): 2180-2186.   doi: 10.7524/j.issn.0254-6108.2018112902
Abstract PDF 7778KB
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Metal-Organic Framework (MOF) material Cu-BTC immersed with ferrous solutions was reduced to iron/copper (Fe0-Cu0) bimetallic particles.with with an average size of ca.20-30 nm The catalytic performance of Fe0-Cu0 bimetallic particles was evaluated to catalyze persulfate for degradation of dibutyl phthalate (DBP). Effects of molar ratios of Fe0/Cu0, persulfate concentration, Fe0/Cu0 dosages and initial pH on DBP degradation were investigated, respectively. The results indicated that DBP removal was increased with increase of the molar ratios of Fe0/Cu0 while the molar ratios of Fe0/Cu0 was less than 1.0. DBP degradation rates also increased with the increase of catalysis dosages and persulfate concentration, which showed highest removal efficiency at the concentrations of 0.3 g·L-1 and 1.62 mmol·L-1 respectively. Besides pH 7.0, the removal efficiency of DBP decreasd with the increase of initial pH values.
Effects of sodium persulfate on benzene series/ ethanol removal in several aquifer media
MENG Wei, JIANG Yaping, CHEN Yudao, WU Shenghua, WEI Yanmei, WEI Junhong
2019, 38(10): 2187-2194.   doi: 10.7524/j.issn.0254-6108.2018112804
Abstract PDF 7938KB
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In order to explore the effects of sodium persulfate on removal of benzene series(benzene, toluene, ethylbenzene and xylene are abbreviated as BTEX)and ethanol from groundwater contaminated by ethanol blended gasoline, a batch experiment was carried out at room temperature by using five kinds of media including lime soil, basalt weathered soil, granite weathered soil, dolomite and river sand. The results showed that the order of removal rates of ethanol was basalt weathered soil > lime soil > river sand > granite weathered soil > dolomite under natural condition. Ethanol was easy to be biodegraded and could hinder the biodegradation of BTEX. Under pure chemical oxidation condition (sterilized), BTEX was more easily to be removed by chemical oxidation than ethanol. Among them, the removal rates of BTEX in lime soil and basalt weathered soil were 94.2% and 97.6%, respectively, and the removal rates of ethanol were 16.9% and 37.0%, respectively. The removal rates of BTEX in river sand, granite weathered soil and dolomite were all over 99%, and the removal rates of ethanol were ranged from 16.9% to 73.6%. Under unsterilized condition, sodium persulfate significantly inhibited the intrinsic microbial action in basalt weathered soil, granite weathered soil and river sand, but had a little influence on lime soil medium. The inherent organic matter and the decrease of pH can affect the BTEX and ethanol removal in persulfate chemical oxidation, whereas the role of iron oxides contained in medium needs further evaluation.
The degradation of volatile organic compounds by porous TiO2 hollow spheres
SHAO Junwei, LYU Jinze, LI Ji, LIU Ruizhe
2019, 38(10): 2195-2202.   doi: 10.7524/j.issn.0254-6108.2018112607
Abstract PDF 10491KB
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To enhance the absorption and mineralization of volatile organic compounds (VOCs), porous TiO2 hollow spheres with different shell-thickness were prepared using SiO2 as template and dodecylamine as the pore-forming agent. Porous SiO2@TiO2 core-shell solid sphere with same shell thickness were synthesized as the control materials. The structural characteristics were characterized by transmission electron microscopy, nitrogen isothermal adsorption-desorption, X-ray diffraction, ultraviolet-visible absorption spectroscopy and surface photovoltage spectroscopy. The photocatalytic degradation experiments were carried out using toluene as a model VOCs. The results showed that the specific surface area, and adsorption performance of the hollow materials were significantly higher than those of the solid materials.Moreover, the hollow structure obviously enhanced the light absorption and separation efficiency of charge carriers compared with the solid TiO2. The reaction rate and mineralization efficiency of toluene for the TiO2 hollow reached up to 1.14 mg·m-3·min-1 and 81.3%, 2.15 and 2.31 times higher than those of the solid material with same shell-thickness, respectively.
Determination of decabromodiphenyl ether in sediment using chromatography-mass spectrometry methods
WANG Huiyu, SONG Shanjun, SHAO Mingwu, YIN Jiandao, YANG Chen, LI Penghui
2019, 38(10): 2203-2211.   doi: 10.7524/j.issn.0254-6108.2018111701
Abstract PDF 1449KB
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The accurate determination of decabrominated diphenyl ethers (BDE-209) is important for the study of its environmental behavior, especially after BDE-209 was officially listed in Stockholm Convention in 2017. This research optimized and evaluated most widely used gas/liquid chromatography-mass spectrometry methods for BDE-209 determination, including GC-NCI-MS, GC-EI-MS, GC-ICP-MS and HPLC-ICP-MS. The performances of each method were investigated for standard solution determination and field sediment samples determination. The limits of quantification ranged from 3-200 ng·mL-1 and linear fitting with coefficients >0.995 ranging from 0.5 to 10 μg·mL-1. The precision of each method was illustrated by relative standard deviation (RSD) of analysis results (n=5) ranging from 0.5%-8.7%. The performances of each method on field sediment sample analysis were investigated and the results showed the precision and matrix effects were 0.7%-15.7% and 98%-166%. GC-EI-MS and GC-NCI-MS signal intensities were enhanced, and the precision was affected by introduction of sediment matrix. Internal standards and matrix match calibration were suggested for these methods to analyze field samples. GC-ICP-MS and HPLC-ICP-MS showed robust performances with neglectable effects by sample matrix.
Simultaneous determination of OCPs and PAHs in soil by GC-MSD with ASE and florisil SPE purification
LIU Bin, YAN Qiang, GUO Li, ZHANG Mingjie, SHI Minfang, HE Xiaomin
2019, 38(10): 2212-2221.   doi: 10.7524/j.issn.0254-6108.2018112605
Abstract PDF 4545KB
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A method for determination of OCPs and PAHs in soils by gas chromato- graphy/mass spectrometry with accelerated solvent extraction and florisil SPE purification was developed. The procedures of extraction and purification,as well as chromatographic and mass spectrometric parameters were optimized. Under the optimized conditions, the detection limits of target compounds were 0.4-3.2 μg·kg-1, and the quantitative lower limits were 1.6-12.8 μg·kg-1. The RSDs(n=6) of two concentration levels were 2.8%-21%, and the recoveries ranged from 61% to 119%. The determination results of soils standard reference materials were all satisfactory. Compared with other methods, the influence of interferent in extract liquid was less, the false positive was eliminated effectively and much higher operating efficiency was obtained in this method.
Determination of aldehydes and ketones in ambient air using adsorbent cartridge followed by high performance liquid chromatography
SI Liguo, XING Guanhua, WANG Chao, TAN Li, CHEN Ye, YU Jianzhao, LIU Fang, YUAN Mao
2019, 38(10): 2222-2228.   doi: 10.7524/j.issn.0254-6108.2019021202
Abstract PDF 1701KB
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The classical method for the determination of carbonyls (aldehydes and ketones) in ambient air was conducted by using 2,4-dinitrophenylhydrazine (DNPH)-coated sorbent cartridge to collect samples. The samples were then analyzed by high performance liquid chromatography. Although this method has been used widely, there are still some drawbacks, eg, the interferences of the background levels of DNPH-cartridges, and the by-products from further reaction on carbonyl-DNP-hydrazone of unsaturated carbonyls with DNPH. This study intends to examine the background levels of three DNPH-cartridges and find an approach to avoid these effects on accurate quantification. The stability of hydrazone derivatives of unsaturated aldehydes, such as acrolein-DNP-hydrazone and crotonaldehyde-DNP-hydrazone, in DNPH-coated cartridge, as well as the effects of their polymerization by-products from the further reaction of hydrazone with DNPH on the quantification. The polymerization of the derivatives in three types of DNPH-coated cartridges purchased from different manufactures was also investigated. It was found that polymerization reaction catalyzed by hydrochloric acid in cartridges was slower than that catalyzed by phosphoric acid. The influence of polymerization products on the accurate quantitation could be reduced, when a hydrochloric acidified DNPH- coated cartridge was used and the sample collection and desorption was conducted within 6 h.
Electrochemical method detect the iron in the river based on AuNPs-nafion modified electrode combined with automatic sampling system
PAN Fei, PAN Dawei, HAN Haitao, WANG Chenchen
2019, 38(10): 2229-2236.   doi: 10.7524/j.issn.0254-6108.2018112616
Abstract PDF 2923KB
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A new detection system was developed based on automatic sampling technology combined with AuNPs-Nafion modified electrode. Through the optimized condition of detection system depends on different parameters, such as the material of the modified electrodes with enrichment of time. Under the optimal conditions, the instrument detection limit for Fe(Ⅲ) was 4.5 nmol·L-1, linear range of 25 nmol·L-1 -1 μmol·L-1. Finally, the total iron content in river water was tested and compared with ICP-AES, basically where test results were the same. This instrument had the advantages of convenience and low detection cost, and it had been wide application prospects in real-time detection.
The morphology of soot and light absorption enhancement under different condition of fuel equivalence ratio
MA Xin, MA Yan, ZHENG Jun, HUANG Congcong
2019, 38(10): 2237-2246.   doi: 10.7524/j.issn.0254-6108.2018112707
Abstract PDF 1437KB
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Laboratory experiments were conducted to investigate the morphology of soot particles and the light absorption enhancement under different fuel equivalence ratios with a soot burner, scanning mobility particle sizer (SMPS), aerosol particle mass analyzer (APM), and three-wavelength photoacoustic soot spectrometer (PASS-3). As the fuel equivalent ratio increased from 1.98 to 2.43, RBC correspondingly increased from 0.07 to 1.03, while the shape factor of soot particles and BC core decreased, which indicated that the particles and the BC core were changed from a highly fractal to a more compact form. A small amount of non-BC coatings could result in evident reconstruction of BC core. The light absorption enhancement of BC was positively correlated with RBC, when the RBC increased from 0.07 to 1.03, the corresponding light absorption enhancement increased from 1.05 to 1.52 (at 781 nm). In addition to the lensing effect, brown carbon (BrC) also contributed to the light absorption enhancement at 405 nm and 532 nm, and the percentage of contribution increased with increasing RBC. In addition, the morphology of soot contributed to the light absorption enhancement of BC. For more compact soot structure, the light absorption enhancement was more obvious, and closer to the theoretically calculated value using the core-shell model. This study showed that the effect of black carbon reconstruction on the light absorption enhancement cannot be ignored.
Human exposure to flame retardants via dust ingestion and hand-to-mouth contact in indoor environment
RU Shuling, JIA Huining, LI Xin, ZHENG Xiaobo, XIE Qilai
2019, 38(10): 2247-2255.   doi: 10.7524/j.issn.0254-6108.2018113002
Abstract PDF 1900KB
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In the present study, dust samples were collected from 17 college dormitories in a university located in Guangzhou. Hand wipe samples were also collected from 32 students residence in these dormitories. The levels and compositions of flame retardants (FRs) in dust and hand wipe samples were investigated. The human exposure to FRs via dust ingestion and hand-to-mouth contact was also estimated. Polybrominated diphenyl ethers (PBDEs), phosphorus flame retardants (PFRs), dechlorane plus (DP), 1,2-bis(2,4,6-tribromophenoxy) ethyl (BTBPE) and decabromodiphenyl ethane (DBDPE) were detected in all samples of indoor dust and hand wipes. The main FRs were BDE 209, DBDPE and PFRs in both dust and hand wipes. ∑PFRs and DBDPE had the highest concentrations in dust and hand wipes. The median concentrations of ∑PFRs and DBDPE were 1294 ng·g-1 and 1751 ng·g-1 in dust, and 277 ng·m-2 and 41.7 ng·m-2 in hand wipes, respectively. The daily exposure values via hand-to-mouth exposure were comparable with the daily exposure values via dust intake. The human exposure to FRs via hand-to-mouth transfer should be of concern.
Distribution characteristics of PCDD/Fs in flue gas from municipal solid waste incineration plant
YANG Hucheng, CHEN Baihang, MU Jingfang, YE Hongyi, LI Shiping, XU Huan, LIU Jingyong
2019, 38(10): 2256-2265.   doi: 10.7524/j.issn.0254-6108.2018112608
Abstract PDF 2796KB
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Based on the date from three incinerators (750 t·d-1) of a municipal solid waste incineration plant in Guangzhou, the distribution characteristics and pollution control effects of PCDD/Fs were investigated before and after incineration purification. The results revealed that the semi-dry deacidification + activated carbon + bag filter technology could effectively remove 97.3%-99.4% of dioxin in the flue gas. The distribution features of PCDD/Fs in the flue gas before purification indicated that dioxins were mainly synthesized in flue gas heat transfer process. The flue gas purification process possessed the following pattern of the removal efficiency of PCDD/Fs:PCDDs > PCDFs and high- chlorinated PCDFs > Low-chlorinated PCDFs. The mass concentrations of 2, 3, 4, 7 and 8-PeCDF in purified flue gas showed the highest coefficient of determination (R2=0.959) with dioxin-equivalent concentrations. Therefore, 2, 3, 4, 7 and 8-PeCDF appeared to be a rapid indicator of the emergency detection of dioxins.
Characteristic analysis of atmospheric major mineral particles/ staphylococcus aureus simulation complex
TANG Jie, ZHAO Yulian, DAI Qunwei, DONG Faqin, HUANG Yunbi, WANG Yan
2019, 38(10): 2266-2273.   doi: 10.7524/j.issn.0254-6108.2018112705
Abstract PDF 5323KB
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Atmospheric environmental pollution is becoming more and more intricacy, the nature and hazard of complexes between mineral particles in the atmosphere and normal bacteria on the surface of the human body is still unclear, therefore, the characteristic research of major atmospheric mineral particles/Staphylococcus aureus complexes is imminent. In this paper, Three mineral particles (quartz, calcite and montmorillonite) and Staphylococcus aureus was selected to preparation complexes. On this basis, the particle size, morphology, surface electrical properties and surface group characteristics of mineral granule/Staphylococcus aureus complexes were analyzed through particle size analyzer, scanning electron microscope (SEM), Zeta potential analyzer and Fourier infrared spectrometer (FTIR). The following results were concluded. The particle size results showed that the particle size of mineral/bacterial complexes was bigger than the orginal mineral. Secondly, scanning electron microscope results showed that a large number of Staphylococcus aureus and its metabolites adhered to the surface of mineral floc. And then Zeta potential results showed that the potential value of the complex tends to the mineral or bacteria potential value. Finally, FTIR results showed that the characteristic peaks from Staphylococcus aureus appeared in mineral granules/Staphylococcus aureus complex, and the displacement phenomenon occurs in other groups of mineral particles. This study is expected to provide basic data support for solving the complex pollution problem in the atmospheric environment with practical significance.
Isolation and identification of a highly efficient DBP degrading bacteria and its degradation characteristics
LI Rongzhen, LI Cheng, ZHAO Xian, LIU Chunjing, MENG Jinkai, XIE Jian
2019, 38(10): 2274-2282.   doi: 10.7524/j.issn.0254-6108.2018111502
Abstract PDF 3406KB
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A bacterial strain DP-2, which could utilize dibutyl phthalate (DBP) as the carbon source and energy source, was isolated from activated sludge of sewage treatment plant. This strain was identified as Acinetobacter sp. by the combination of morphological observation, biochemical identification and 16S rDNA sequence analysis. The effect of inoculation amount, DBP concentration, NaCl concentration and carbon source on the DBP degradation characteristics of DP-2 was studied by a single factor test. The results showed that the DBP degradation rate of DP-2 could reach more than 90% within 3 days when the initial inoculation amount was more than 10% and the initial DBP concentration was 10 mg·L-1. The degradation rate of DBP could reach more than 90% within 6 days when the initial DBP concentration was 5-50 mg·L-1, however, the DBP degradation rate was only 26.88% when the DBP concentration reached to 1000 mg·L-1, which indicated higher DBP concentration could impact the growth of DP-2. The optimum NaCl concentration range of DP-2 was 0-20 g·L-1 for DBP degradation. In addition, sodium acetate, sucrose and glucose could promote the degradation of DBP, and the effect of glucose was the most obvious. Based on this, a response surface methodology test was conducted to optimize the culture conditions of DP-2 for DBP degradation. The results showed that the DBP degradation rate of DP-2 was 85.86% at salinity of 5 g·L-1, inoculation amount of 17.14% and DBP concentration of 9.81 mg·L-1.
Effects of precipitation ripening on the catalytic diesel soot purification of Ce0.7Mn0.3Ox mixed oxides
LUO Liping, TANG Linxi, ZHOU Zizhong, YANG Yan, LI Yunxiang, REN Liping, ZENG Chao, ZHANG Na, YANG Zhengzheng
2019, 38(10): 2283-2293.   doi: 10.7524/j.issn.0254-6108.2018112901
Abstract PDF 15095KB
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CeO2-MnOx mixed oxides with a molar ratio of Ce:Mn=7:3 were prepared by precipitation ripening method, and labeled as Ce0.7Mn0.3Ox-PR. The catalytic soot oxidation activity of prepared Ce0.7Mn0.3Ox-PR was compared with the traditional commercial Ce0.7Mn0.3Ox soot oxidation catalyst (prepared by co-precipitation method, labeled as Ce0.7Mn0.3Ox-CP). Meanwhile, the catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS) and Raman spectra. Results displayed that the precipitation ripening could efficiently promote the growth of crystalline grain and stabilize the textual features of catalyst. For the Mn species, the precipitation ripening was beneficial for the generating of Mn4+, which was a promoting factor for the oxygen mobility of CeO2; furthermore, the precipitation ripening was favorable for Mn ions to enter into the CeO2 lattice and retarding the agglomeration of MnOx species over catalyst surface. Mn ions into CeO2 lattice were able to significantly enhance the amounts of lattice oxygen and oxygen vacancies of Ce0.7Mn0.3Ox-PR catalyst, and hence improving the catalytic soot oxidation activity of Ce0.7Mn0.3Ox-PR catalyst. Since lattice oxygen and oxygen vacancies were beneficial for the formation of active oxygen. Finally the catalytic activity tests showed that the light-off temperature (T50) and complete conversion temperature (T90) for soot oxidation of Ce0.7Mn0.3Ox-PR was about 362℃ and 419℃, respectively; which are obviously better than the traditional Ce0.7Mn0.3Ox-CP catalyst (T50 and T90 are 376℃ and 457℃, respectively).
Preparation and characterization of graphene oxide and its adsorption and separation properties of rhamnolipid from fermentation broth
CUI Ying, NIE Maiqian, NIE Hongyun, DIWU Zhenjun, SUN Han
2019, 38(10): 2294-2299.   doi: 10.7524/j.issn.0254-6108.2018112604
Abstract PDF 4235KB
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Graphene oxide (GO) was prepared using the method of improved Hummers, and its adsorption and separation properties of rhamnolipid from the fermentation broth of P. aeruginosa were studied. The results showed that, graphene has been oxidize and peeled to fewer layers with obviously lager specific surface area after oxidized by Hummer method. The adsorption of rhamnolipid on the surface of GO reached equilibrium quickly and the maximum adsorption amounts got to be 1.7 g·g-1 when pH and temperature of the fermentation broth was 4.0 and 25℃ respectively. The once desorption rate of rhamnolipid reached 86.1% using sodium hydroxide solution with pH of 13 as optimum desorption reagent. Meanwhile, the adsorbents of GO could be used recycling.
The effects of pH, ionic strength and particle size on the stability of graphene oxide
MAO Han, DONG Hui, Ghosh Saikat, WANG Zhenquan, GUO Jin
2019, 38(10): 2300-2305.   doi: 10.7524/j.issn.0254-6108.2018112004
Abstract PDF 5676KB
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High specific surface area and abundance of functional groups have facilitated the potential application of graphene oxide(GO) as a suitable material for membrane technology. However, synthesis techniques have not ensured the uniformity of GO transverse size required for membrane generation. In addition, poly-dispersity of GO in natural water attributed to variation in stability of GO as a function of pH and ionic strength. In this article, we studied the role of transverse size and pH and ionic strength on GO's electric double layer charge or interaction forces required for designing assembled structures. The role of solution parameters on DLVO forces were identified from the force-distance curve (F-D) obtained from in situ Atomic force microscope (AFM). The electrostatic repulsive force on GO tended to increase with the rise in pH possibly due to enhance ionization of the surface functional moieties. However, increasing ionic strength reduced the electrical double layer repulsive force and the obtained data was in coherence with DLVO theory. Particle size-dependent surface charge inhomogeneity of GO-platelets were determined from zeta potential and Kelvin probe force microscopy (KPFM) measurements.
Bioavailability of selenium and its influencing factors in soil of Jizhou district, Tianjin
XIE Wei, YANG Yaodong, HOU Jiayu, JIAN Guiqin, LI Guocheng
2019, 38(10): 2306-2316.   doi: 10.7524/j.issn.0254-6108.2019042802
Abstract PDF 6088KB
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Selenium-enriched soil in Jizhou district Tianjin was investigated. Total selenium, available selenium and various species of selenium in soil were analyzed. Moreover, the influencing factors of available selenium in soil were also evaluated. The results showed that the content of total selenium ranged from 0.14 to 0.65 mg·kg-1 in the selenium-enriched soils of Jizhou district, with a mean of 0.37 mg·kg-1, which was higher than the environmental background value of Jizhou (0.23 mg·kg-1) and the national average level (0.29 mg·kg-1). The average available selenium in soil was 0.021 mg·kg-1, accounting for 5.63% of the total selenium. The soil selenium in the study area was dominated by organic matter-bound selenium and residual selenium. The average contents of the two species were 0.14 and 0.11 mg·kg-1, accounting for 44% and 35% of the total selenium, respectively. The selenium contents in soluble, exchangeable and carbonate bound selenium were less, accounting for only 4.6%, 1.7% and 0.9%. The content of available selenium in soil was approximately equal to the amount of soluble selenium, exchangeable selenium and carbonate-bound selenium, and there was no significant difference among them. Available selenium in soil was positively correlated with total selenium, pH and organic matter. Partial correlation analysis showed that available selenium was mainly affected by soil selenium content and pH.
The heavy metals contamination in Liaodong Bay and its adjacent waters
WANG Xiao, ZHANG Wensi, CHI Guangxi, LIU Baolin
2019, 38(10): 2317-2326.   doi: 10.7524/j.issn.0254-6108.2018112606
Abstract PDF 1286KB
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The concentration heavy metals in seawater, surface sediments and organisms, and their spatial and temporal distributions in Liaodong Bay and its adjacent waters, as well as risk assessment, were reviewed in the paper. The results showed that Cd, Zn and Pb were the main heavy metal contamination factors in seawater, and the content of heavy metals in sediments decreased significantly with the increasing distance to coastal and estuarine zone, which might be closely related to human activities. The level of heavy metal contamination in Liaodong Bay and its adjacent waters was generally lower, and its spatial distribution showed a decreasing trend from inshore sea to central sea area. The pollution in the northern Liaodong Bay was more serious than that in the eastern and western area. The intertidal zone of Jinzhou Bay showed a strongly potentially ecological hazard risk. The enrichment degree of heavy metals in organisms was affected by the environmental quality of seawater. Cd concentration in seashore shellfish in Liaodong Bay generally exceeded the second class national standard for marine biological quality.
The seasonal dynamics of nitrogen and rhizosphere effects in the typical saline-alkali vegetation communities of the Yellow River Estuary wetland
LIANG Kun, FAN Yuqing, Kudakwashe Meki, DUN Meng, YAN Qin, ZHENG Hao, LI Fengmin, LUO Xianxiang
2019, 38(10): 2327-2335.   doi: 10.7524/j.issn.0254-6108.2018120301
Abstract PDF 1954KB
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In this study, the temporal-spatial distribution patterns of nitrogen (N) and the rhizosphere effect of salsa (Suaeda salsa) and reed (Phragmites australis) were investigated in the Yellow River Estuary wetland. The data was based on the three times of field ecological survey of halophyte communities conducted in May, August, and October in the same year, respectively. Moreover, the effects of soil physic-chemical properties on the soil N distribution characteristics were elucidated with the redundancy analysis (RDA) based on a linear model. The results showed that the total N content in the soil of the Yellow River Estuary wetland was higher in May and October than those in August. Organic N dominated in the total N, and the inorganic N mainly consisted of NH4+-N. In general, the total N content of surface soil followed the order:reed land > salsa land > mudflats, of which the N content of mudflats was about 30%-50% lower than those of reed and salsa land. The contents of total N, organic N, NH4+-N and NO3--N in the mudflats, salsa and reed land at the surface layer (10 cm) of soils indicated the highest N content in all the soil layers, and the soil N content decreased with the increasing soil depth. The leaching of NO3--N were significant across the soil profile, its maximum value appeared at the depth of 30 cm. The N content of the rhizosphere soils in the salsa and reed land were significantly higher than those of non-rhizosphere soils (P < 0.05). RDA analysis showed that TOC and pH were two primary factors influencing the N distribution. In addition, vegetation types also affected the N accumulation in the soils. Generally, soil N accumulated in the order reed land > salsa land > mudflats, and notably varied across the different seasons. Compared with the reed, the salsa accumulated more N in its rhizosphere soil during in August.
Evolution characteristics of nutrients and chemical compositionsof groundwater before and after autumn irrigation: Taking Wulate Irrigation Area as an example
YUAN Hongying, YANG Shuqing, DING Xuehua, WANG Bo, YANG Xinmin
2019, 38(10): 2336-2347.   doi: 10.7524/j.issn.0254-6108.2019050802
Abstract PDF 13661KB
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In order to reveal the characteristics of groundwater nutrients changes and explore the evolution and sources of water chemical compositions before and after autumn irrigation,this paper selected Wulate irrigation area as the research object, tracked and monitored the groundwater and irrigation water from August to November 2018, and 160 groundwater samples were collected. The spatial variation, the Piper diagram and the Gibbs map were used to analyze the dynamic changes of nitrogen and phosphorus elements and water chemical composition in groundwater and irrigation water, which have certain guiding significance for local agricultural production and groundwater environmental protection. The results show that, TN and TP contents in Wulate irrigation area groundwater were extremely different, and the TN content increased from August to November. Human activities changed the TN content unsteadily before and after autumn irrigation. The TN contents in the areas where there were many drainage ditches or channels and proceed autumn irrigation are obviously higher than at other areas. Due to strong irnmobilization of phosphorus by soil the spatial variation of TP content has no obvious pattern in groundwater before and after autumn irrigation, so the TP content is hardly affected by autumn irrigation. According to the distribution of the main salt segregants in the groundwater, the Wulate irrigation area is mainly divided into four areas, of which the salt content of the III area is the highest,and increased obviously after autumn irrigation. The mean values of Na+ and Cl- reached 857.52 mg·L-1 and 1246.09 mg·L-1,respectively in November. The main water chemistry type of groundwater in the irrigation area are Na+-Mg2+-Cl--SO42- type and Na+-Cl- type. The chemical source of groundwater is basically the same every month. Irrigation water supply and soil leaching are the reasons why Cl- and Na+ dominate the chemical composition of groundwater. Gibbs map shows that the chemical composition of the Yellow River water for irrigation is mainly controlled by the weathering and evaporation of the rock. The chemical source of groundwater is mainly controlled by evaporation and human activities, and the anion is more affected by human activities. Among them, farmland irrigation and sewage discharge are the most important factors.
The impact of cage fish-farming on the aquatic environment in Poyang Lake, China: A case study of Duchang water area
WANG Maolan, LIU Jingjing
2019, 38(10): 2348-2355.   doi: 10.7524/j.issn.0254-6108.2018112615
Abstract PDF 2336KB
Abstract:
In order to understand the effect of net-cage culture to the water body, the water samples were collected from cage culture area, surrounding area and control point in the Duchang County of Poyang Lake at October 2017 and March 2018. The influence of cage culture on water environment (water temperature, DO, pH, Chla, TN, TP, etc.) was discussed. The state of eutrophication of water body was evaluated by using comprehensive nutrition state index. The results showed that cage culture had little influence on water temperature and pH, but the obvious influence on DO, Chla and nutrient content. In March and October, DO was lower than the control point, but Chla was higher than the control point, significantly. The contents of TN in the cage area were 2.26-2.40 mg·L-1 and 2.05-2.72 mg·L-1 in March and October, respectively, and they were 1.49 mg·L-1 and 1.14 mg·L-1 in the control point, respectively. The concentrations of TP were 0.24-0.42 mg·L-1 and 0.11-0.23 mg·L-1 respectively, they were 0.18 mg·L-1 and 0.11 mg·L-1 in the comparison point, respectively. The maximum concentrations of TN and TP appeared in the cage area. The concentrations of NH4+-N were 0.66-1.05 mg·L-1 and 0.18-0.39 mg·L-1, respectively. The contents of NO3--N were 0.72-1.01 mg·L-1 and 0.38-0.62 mg·L-1, respectively. In March, the contents of NH4+-N, NO3--N, TN and TP in the study area were higher than those in October. The net-cage culture water body was in the Mesotrophy.
Effects of combined biochar and hydrogen peroxide remediation on soil properties of thermal power plants and cabbage growth
WEN Zhihao, ZENG Lusheng, CHAI Chao, WU Juan
2019, 38(10): 2356-2365.   doi: 10.7524/j.issn.0254-6108.2018120605
Abstract PDF 2805KB
Abstract:
In this paper, a method for remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil by biochar and hydrogen peroxide has been established. The contaminated soil was collected in farmland near thermal Power Plant in Zhucheng City, Shandong Province. Pot experiments were conducted to study the effects of different amount of biochar combined with hydrogen peroxide on Chinese cabbage growth and PAHs content. The results showed that proper application of biochar and H2O2 could promote the growth of Chinese cabbage and effectively reduce the content of PAHs in soil and Chinese cabbage. Compared with T1 (no biochar), the biomass of Chinese cabbage increased by 8%-15%, and the SPAD value increased by 25%-50%. The Chinese cabbage's fluorescence parameters and spectral reflectance were improved, and the content of PAHs in Chinese cabbage and soil decreased significantly. Moreover, the pH of acidified soil increased by 0.2-0.6 units, the content of soil organic matter increased by 9.5%-45.6%, and the nutrients such as available phosphorus and available potassium increased to a certain extent. Among treatments, T7 (0.5‰ H2O2+2‰) had the best remediation effect, and the removal rates of PAHs in tested Chinese cabbage and soil reached up to 69.6% and 58.8%, respectively. In addition, T3 (2‰ biochar) also had good removal effects, and the removal rates of PAHs in tested Chinese cabbage and soil reached were 42.9% and 54.6%, respectively. Therefore, it is recommended to refer to the application in the practice.
Remediation of heavy metal contaminated soil by combined EGTA washing and KH2PO4 immobilization
WANG Minxing, ZHANG Jinyong, XIAO Yang, WANG Shize
2019, 38(10): 2366-2375.   doi: 10.7524/j.issn.0254-6108.2018111404
Abstract PDF 1634KB
Abstract:
In order to further reduce the environmental risk of heavy metals remaining in the soil after chelation, a combination method of washing and immobilizatio was used to repair heavy metal contaminated soil. The washing rates, leaching concentration and chemical specification of heave metals in soil by ethylenebis(oxyethylenenitrilo)tetraacetic acid (EGTA) washing, potassium dihydrogen phosphate (KH2PO4) immobilization and their combination treatment were studied. The TCLP method and BCR method were used to analyze the leaching concentration and chemical form distribution of heavy metals. An environmental risk assessment method covering soil heavy metal concentration, bioavailability and toxicity was constructed to evaluate the remediation efficiency. The results showed that EGTA had higher removal rates of Cu and Cd. EGTA treatments reduced the leaching concentration of Cu, Zn and Cd in soil, and the increased the leaching concentration of Pb. Considering chemical specification of heavy metals, EGTA treatments reduced the reducible Cu, weak acid extractable and reducible Zn, the reducible and residual Pb, the weak acid extractable and reducible Cd residues in soil. With the increase of KH2PO4 dosage, the leaching concentration of Pb, Cd and Cu showed a downward trend, and the leaching concentration of Zn increased first and then decreased. The effect of KH2PO4 on the chemical specification of heavy metals was mainly reflected in the decrease of the proportion of the weak acid extractable fraction or the reducible fraction, and the increase of the residual fraction. The combination of EGTA and KH2PO4 significantly reduced the reducible heavy metals and the weak acid extractable Pb and Cd residues. Combined remediation had a synergistic effect on reducing cadmium leaching concentrations and environmental risks. Washing was suitable for Zn contaminated soil remediation, immobilization was suitable for Pb contaminated soil, and combined washing and immobilization was suitable for Cd or Cu contaminated soil deep remediation.
Alternating current electric field promotes willow plant to remediate cadmium contaminated soil
NI Xing, LI Yaqian, WANG Shengnan, LIU Dan, YE Zhengqian
2019, 38(10): 2376-2385.   doi: 10.7524/j.issn.0254-6108.2018112203
Abstract PDF 1513KB
Abstract:
A soil pot experiment was conducted to study the effects of alternating current (AC) electric field(0, 0.5, 1 V·cm-1)on cadmium (Cd) availability of soil and physiology and biochemistry of willow at seedling stage and the Cd absorption and accumulation. The results indicated that application of AC electric field slightly affected the pH value of the soil, but the soil available Cd concentrations increased greatly with increasing the electric field gradient. The available Cd concentration in soil treated with AC electric field of 1 V·cm-1 was 29.11% greater than that of the control (P<0.05). The application of AC electric field was beneficial to willow sapling growth. The plant height, leaf area and biomass of the willow saplings increased with the increase of voltage gradient:they were significantly higher in 1 V·cm-1 treated willow saplings than that of the control 35.49%, 22.52%, 36.84%, 85.00%, respectively (P<0.05). The application of AC electric field was also beneficial to root growth as indicated by root morphology index. The root length, root surface area and root tip number of 0.5 V·cm-1 treated willow saplings were the highest, which were significantly higher than the control 49.96%, 76.69% and 43.46% (P<0.05), respectively. Application of AC electric field also promoted photosynthesis and affected chlorophyll fluorescence parameters of willow saplings. The net photosynthetic rate (Pn), stomatal conductance (Gs), PSII photosynthetic electron transport quantum effect Υ(Ⅱ), photochemical quenching coefficient qP, photosynthetic electron transfer rate ETR of 0.5 V·cm-1 treated willow saplings were the highest, which were higher than the control 36.00%, 60.00%, 22.86%, 24.07% and 22.35% (P<0.05), respectively. Consequently, the application of AC electric field promoted the cleanup rate of Cd in soil by willow, but different voltage gradients resulted in different efficiency. The 0.5 V·cm-1 treatment increased Cd accumulation of willow by increasing plant biomass, while the 1 V·cm-1 treatment increased the Cd accumulation of willow by increasing plant biomass and promoting Cd uptake by the plants. Therefore, the AC electric field combined with phytoremediation technology improved the absorption and accumulation of Cd in plants, and could have a bright application prospect in practice.
Pollution characteristics and ecological risk assessment of heavy metals in Shaying River Basin
DING Tingting, LI Qiang, DU Shilin, LIU Yafeng, ZHANG Yahui, ZHANG Jin, WANG Yizhe, HE Liansheng
2019, 38(10): 2386-2401.   doi: 10.7524/j.issn.0254-6108.2018121806
Abstract PDF 20992KB
Abstract:
In order to study the distribution characteristics of heavy metal pollution in the water environment of Shaying River Basin, water samples and surface sediment samples from 40 sites were collected in July 2018, and 9 heavy metals (Cu, Zn, As, Hg, Cd, Cr, Pb, Mn and Ni) were determined. The results showed that the average content of 9 heavy metals in surface water of Shaying River Basin were 1.30, 9.09, 2.87, 0.24, 0.14, 0.38, 0.96, 56.82 and 0.95 μg·L-1, respectively. 17.5% of Hg and 5.0% of Mn exceeded the Environmental Quality Standard for surface water (GB 3838-2002). The average contents of 9 heavy metals in surface sediment were 23.38, 86.62, 10.72, 0.14, 0.34, 55.26, 24.01, 536.99 and 30.79 μg·g-1, respectively. All the elements exceeded their background values in the soil of Henan Province, among which the overshooting rates of Hg and Cd were 90% and 97%, respectively. The degree of heavy metal contamination in the water decreased in the following order with the method of Nemerow comprehensive pollution index (Pi):Hg > Mn > As > Ni > Cd > Zn=Pb=Cr > Cu. About 18% of surface water was found to be seriously polluted and the main pollutant was Hg, followed by Mn. It was revealed that the main pollution factors in sediment was Hg and Cd, the sequence of ecological risk was Hg > Cd > Ni > As > Cu > Pb > Cr > Zn > Mn with the method of potential ecological risk index. In general, sediment pollution was more serious than surface water pollution. The results indicated that there have three major sources of pollution in the Shaying River Basin using the method of cluster analysis. In the surface water, the pollution sources of Hg and Mn could be attributed to the wastewater discharge in metal mine smelting, plastic battery, electronics industry. In the sediment, the pollution source of Cd was mainly related to the wastewater discharge in smelting and processing, and Hg was mainly related to the metal mine smelting, electric power, chemical raw materials and chemical manufacturing, machinery manufacturing, papermaking and other industries.
Simultaneous determination of three amphetamines in urine by CLAM-2000 coupled with LC-MS/MS
YI Wei, LI Qiang, HAO Hongyuan, SUN Youbao, HUANG Taohong, CHEN Jianli
2019, 38(10): 2402-2404.  
Abstract PDF 2054KB
Abstract:
In this paper, a fast and simple method, which was for simultaneous determination of 3 amphetamines in urine by CLAM-2000 coupled with LC-MS/MS, was established. As a fully automatic preparation unit, the CLAM-2000 deproteinizes biological samples(such as whole blood, plasma, serum, urine) by adding methanol/acetonitrile, shaking and filtering the samples, and automatically transfers the vials with target component to the LC-MS/MS autosampler for sample injection. From sample preparation to analysis, fully automatic processing improve analysis data accuracy and repeatability, and reduce operation mistakes and infection risks. Under the optimized conditions, good linearity was obtained for 3 Amphetamines with correlation coefficients (r) ranging from 0.9995 to 0.9997. The precision was investigated by analyzing the spiked samples 6 times. The results of precision based on the relative standard deviation (RSD%) of retention time and peak area, and the RSD values were both less than 0.4% and 5.0%. And the measured values of QC samples were within the reliable range.