The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-s...The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-stable aggregate fractions and to study their influence on soil organic carbon (C<sub>org</sub>) content. Soil samples were taken from a forest-site, Gogerddan (G) and a semi-rural site, Hazelrigg (H) in Great Britain, from 0-2 and 2-5 cm and 0-4 and 8-12 cm soil depth, respectively. POPs analyzed were PAHs, PCBs, total DDT, PBDEs and HCB. The bulk soil analysis showed that the concentration of POPs was significantly higher (p ≤ 0.05) in forest site G than in semi-rural site H, particularly at the surface soil levels compared to the subsurface soil depths in both sites. Total concentrations of PCBs and PAHs of both sites were positively correlated with C<sub>org</sub> contents. POPs concentrations and C<sub>org</sub>, N<sub>t</sub> contents of forest site G were significantly higher (p ≤ 0.05) in water-stable macro aggregates (>0.25, >1, >2 mm) than the micro aggregates (>0.053 mm). The POP concentrations of all aggregate fractions after normalizing to their respective C<sub>org</sub> content were increased due higher contamination and strong sorption by C<sub>org</sub>. These results showed a strong effect of C<sub>org</sub> on the partitioning of organic pollutants to soil aggregate size fractions. The present study affirms the ecological significance of forest soils act as a potential sink of POPs. In summary, our results suggest that aggregate fractions may promote soil C storage and act as a potential POP sink in surface soil without increasing their concentration in the aggregate fraction of subsoil.展开更多
This essay briefly introduces the historical development of gas chromatography and mass spectrometry technology,it combines important results of GC and GC-MS in environmental monitoring,GC and GC-MS may analyse Polynu...This essay briefly introduces the historical development of gas chromatography and mass spectrometry technology,it combines important results of GC and GC-MS in environmental monitoring,GC and GC-MS may analyse Polynuclear aromatic hydrocarbons,Pesticide,PCBs,PDBEs and Multicomposit ion of organic pollutants,etc.It also elaborates the developing trend of the gas chromatography technology.展开更多
It′s very useful tools for an instant analysis of organic pollutants monitoring using the HAPSITE portable GC-MS.It discusses how to use HAPSITE portable GC-MS in emergency monitoring and treatment.
Plasma water treatment technology, which aims to produce strong oxidizing reactive particles that act on the gas-liquid interface by way of discharging, is used to treat the organic pollutants that do not degrade easi...Plasma water treatment technology, which aims to produce strong oxidizing reactive particles that act on the gas-liquid interface by way of discharging, is used to treat the organic pollutants that do not degrade easily in water. This paper presents a diffuse-discharge plasma water treatment method, which is realized by constructing a conical air gap through an uneven medium layer. The proposed method uses water as one electrode, and a dielectric barrier discharge electrode is constructed by using an uneven dielectric. The electric field distribution in the discharge space will be uneven, wherein the long gap electric field will have a smaller intensity, while the short one will have a larger intensity. A diffuse glow discharge is formed in the cavity. With this type of plasma water treatment equipment, a methyl orange solution with a concentration of 10 mg 1-1 was treated, and the removal rate was found to reach 88.96%.展开更多
In this paper, the characteristics of integrated biological aerated filter (IBAF) applied to municipal wastewater treatment were studied in a pilot scale experiment. The experimental results showed that IBAF has high ...In this paper, the characteristics of integrated biological aerated filter (IBAF) applied to municipal wastewater treatment were studied in a pilot scale experiment. The experimental results showed that IBAF has high efficiencies in removing organic pollutants, such as CODCr and SS, in municipal wastewater. The removal rates of CODCr and SS can reach over 90% and 80%, respectively, when COD and SS in the influent are 234 mg L1 and 112 mg L1, hydraulic retention time (HRT) is 8 h, and the aerated intensity is in the range of (0.5 to 0.6) L m2 s1.展开更多
The effectiveness of ClO_2 bleaching as a replacement for conventional Cl_2 bleaching,which is intensively practiced in developing countries,to reduce polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in non...The effectiveness of ClO_2 bleaching as a replacement for conventional Cl_2 bleaching,which is intensively practiced in developing countries,to reduce polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in non-wood pulp and paper mills has not been field tested.The first field study was performed to investigate PCDD/F variations when ClO_2 bleaching was used as a substitute for conventional Cl_2 bleaching in a non-wood pulp and paper mill.It was found that the PCDD/F toxic equivalents(TEQs)in solid and effluent samples were approximately 1.3–14.9 times lower when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.2,3,7,8-Substituted tetrachlorinated dibenzofurans(2,3,7,8-TCDF)were the dominant contributors to total PCDD/F TEQs in samples from the investigated mill when using conventional Cl_2 bleaching.The formation amounts of 2,3,7,8-TCDF were reduced from 1.56–2.76 pg TEQ/g to 0.02–0.32 pg TEQ/g in solid samples when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.The replacement of Cl_2 with ClO_2 might decrease the chlorination reactions of dibenzofuran as potential precursors,and thus reduce the formation amounts of 2,3,7,8-TCDF.The results could provide important knowledge for suggesting the best available technique for PCDD/F reduction for non-wood pulp and paper mills in developing countries.展开更多
Along with the rapid development of oil industries internationally,petroleum prospecting and exploitation activities are growing intensively.Especially in China,with the fastest economic growth in the world and shorta...Along with the rapid development of oil industries internationally,petroleum prospecting and exploitation activities are growing intensively.Especially in China,with the fastest economic growth in the world and shortage of petroleum resources,we are leading the practices of petroleum deep exploitation.Obviously,the risk of damage to the natural environment from these activities is high.Oil contamination in soils and groundwater is becoming a big issue along with pesticide pollution,which makes organic pollution prevention and control （OPPC） much more complex.In this paper,based on recent research on oil-contaminated soil at home and abroad,we make comments on the remediation technologies for polluted soil,emphasizing bioremediation techniques and degradation mechanisms in order to push forward research into bound organic pollution prevention and control （OPPC）,especially in China.展开更多
A BiVO_4 photoanode with exposed(040) facets was prepared to enhance its photoelectrochemical performance.The exposure of the(040) crystal planes of the BiVO_4 film was induced by adding NaCl to the precursor solution...A BiVO_4 photoanode with exposed(040) facets was prepared to enhance its photoelectrochemical performance.The exposure of the(040) crystal planes of the BiVO_4 film was induced by adding NaCl to the precursor solution. The asprepared BiVO_4 photoanode exhibits higher solar-light absorption and charge-separation efficiency compared to those of an anode prepared without adding Na Cl. To our knowledge,the photocurrent density(1.26 m A cm^(-2) at 1.23 V vs. RHE) of as-prepared BiVO_4 photoanode is the highest according to the reports for bare BiVO_4 films under simulated AM1.5 G solar light, and the incident photon-to-current conversion efficiency is above 35% at 400 nm. The photoelectrochemical(PEC)water-splitting performance was also dramatically improvedwith a hydrogen evolution rate of 9.11 lmol cm^(-2) h^(-1), which is five times compared with the BiVO_4 photoanode prepared without NaCl(1.82 lmol cm^(-2) h^(-1)). Intensity-modulated photocurrent spectroscopy and transient photocurrent measurements show a higher charge-carrier-transfer rate for this photoanode. These results demonstrate a promising approach for the development of high-performance BiVO_4 photoanodes which can be used for efficient PEC water splitting and degradation of organic pollutants.展开更多
Azo dyes discharged in the environment are persistent organic pollutants （POPs）, which are very difficult to remove. We developed a microwave-assisted Fenton-like process to degrade methyl orange （MO）, an azo dye,...Azo dyes discharged in the environment are persistent organic pollutants （POPs）, which are very difficult to remove. We developed a microwave-assisted Fenton-like process to degrade methyl orange （MO）, an azo dye, with hydrogen peroxide （H2O2） catalyzed by chromium compounds coexisting with MO in the solution. Comparison between the Cr（Ⅲ）-H2O2 and Cr（Ⅵ）-H2O2 systems shows＂ that Cr（Ⅵ） has a stronger and more stable catalytical activity than Cr（Ⅲ）, and Cr（Ⅲ） is more susceptible to a change in the acidity or alkalinity of the reaction system. With a Cr（Ⅵ） concentration of 10 mmol L^-1 or a Cr（Ⅲ） concentration of 12 mmol L^-1 in the solution under the microwave irradiation of a power larger than 300 W for 3 min, 10 mmol L^-1 H2O2 can degrade more than 95% of 1 000 mg L^-1 methyl orange; when the microwave power is increased to 700 W, the same amount of H2O2 can degrade all methyl orange in the solution with the same amount of Cr（Ⅵ ） catalyst. Ultraviolet-visible spectrography indicates the cleavage of the azo bond in methyl orange after treatment, suggesting the potential o of this Fenton-like process to degrade azo dye POPs. Reusing waste chromium compounds coexisting with dyestuff in wastewater to catalyze the degradation of azo dyes could be a cost-effective technique for azo dyes and chromate manufacturers and/or users to treat their wastewater and prevent POPs from endangering the environment. This is of particula importance to controlling the water quality of the Three Gorges Reservoir.展开更多
基金financed by the Higher Education Commission(HEC) of Pakistan and German Academic Exchange Service(DAAD)
文摘The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-stable aggregate fractions and to study their influence on soil organic carbon (C<sub>org</sub>) content. Soil samples were taken from a forest-site, Gogerddan (G) and a semi-rural site, Hazelrigg (H) in Great Britain, from 0-2 and 2-5 cm and 0-4 and 8-12 cm soil depth, respectively. POPs analyzed were PAHs, PCBs, total DDT, PBDEs and HCB. The bulk soil analysis showed that the concentration of POPs was significantly higher (p ≤ 0.05) in forest site G than in semi-rural site H, particularly at the surface soil levels compared to the subsurface soil depths in both sites. Total concentrations of PCBs and PAHs of both sites were positively correlated with C<sub>org</sub> contents. POPs concentrations and C<sub>org</sub>, N<sub>t</sub> contents of forest site G were significantly higher (p ≤ 0.05) in water-stable macro aggregates (>0.25, >1, >2 mm) than the micro aggregates (>0.053 mm). The POP concentrations of all aggregate fractions after normalizing to their respective C<sub>org</sub> content were increased due higher contamination and strong sorption by C<sub>org</sub>. These results showed a strong effect of C<sub>org</sub> on the partitioning of organic pollutants to soil aggregate size fractions. The present study affirms the ecological significance of forest soils act as a potential sink of POPs. In summary, our results suggest that aggregate fractions may promote soil C storage and act as a potential POP sink in surface soil without increasing their concentration in the aggregate fraction of subsoil.
文摘This essay briefly introduces the historical development of gas chromatography and mass spectrometry technology,it combines important results of GC and GC-MS in environmental monitoring,GC and GC-MS may analyse Polynuclear aromatic hydrocarbons,Pesticide,PCBs,PDBEs and Multicomposit ion of organic pollutants,etc.It also elaborates the developing trend of the gas chromatography technology.
文摘It′s very useful tools for an instant analysis of organic pollutants monitoring using the HAPSITE portable GC-MS.It discusses how to use HAPSITE portable GC-MS in emergency monitoring and treatment.
基金supported by National Natural Science Foundation of China (51577011)
文摘Plasma water treatment technology, which aims to produce strong oxidizing reactive particles that act on the gas-liquid interface by way of discharging, is used to treat the organic pollutants that do not degrade easily in water. This paper presents a diffuse-discharge plasma water treatment method, which is realized by constructing a conical air gap through an uneven medium layer. The proposed method uses water as one electrode, and a dielectric barrier discharge electrode is constructed by using an uneven dielectric. The electric field distribution in the discharge space will be uneven, wherein the long gap electric field will have a smaller intensity, while the short one will have a larger intensity. A diffuse glow discharge is formed in the cavity. With this type of plasma water treatment equipment, a methyl orange solution with a concentration of 10 mg 1-1 was treated, and the removal rate was found to reach 88.96%.
基金Funded by the National Scientific and Technological Project of "the Tenth Five-Year Plan" (No. 2004BA604A01)
文摘In this paper, the characteristics of integrated biological aerated filter (IBAF) applied to municipal wastewater treatment were studied in a pilot scale experiment. The experimental results showed that IBAF has high efficiencies in removing organic pollutants, such as CODCr and SS, in municipal wastewater. The removal rates of CODCr and SS can reach over 90% and 80%, respectively, when COD and SS in the influent are 234 mg L1 and 112 mg L1, hydraulic retention time (HRT) is 8 h, and the aerated intensity is in the range of (0.5 to 0.6) L m2 s1.
基金support provided by the National 973 program (No. 2015CB453100)the Youth Innovation Promotion Association CAS (No. 2016038)the Strategic Priority Research Program of the CAS (No. XDB14020102)
文摘The effectiveness of ClO_2 bleaching as a replacement for conventional Cl_2 bleaching,which is intensively practiced in developing countries,to reduce polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in non-wood pulp and paper mills has not been field tested.The first field study was performed to investigate PCDD/F variations when ClO_2 bleaching was used as a substitute for conventional Cl_2 bleaching in a non-wood pulp and paper mill.It was found that the PCDD/F toxic equivalents(TEQs)in solid and effluent samples were approximately 1.3–14.9 times lower when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.2,3,7,8-Substituted tetrachlorinated dibenzofurans(2,3,7,8-TCDF)were the dominant contributors to total PCDD/F TEQs in samples from the investigated mill when using conventional Cl_2 bleaching.The formation amounts of 2,3,7,8-TCDF were reduced from 1.56–2.76 pg TEQ/g to 0.02–0.32 pg TEQ/g in solid samples when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.The replacement of Cl_2 with ClO_2 might decrease the chlorination reactions of dibenzofuran as potential precursors,and thus reduce the formation amounts of 2,3,7,8-TCDF.The results could provide important knowledge for suggesting the best available technique for PCDD/F reduction for non-wood pulp and paper mills in developing countries.
基金supports from the New Century Excellent Talents in University of Ministry of Education (NCET-09-0765)the China Scholarship of Council (2009644509)the Natural Scientific Funds of China (40973064)
文摘Along with the rapid development of oil industries internationally,petroleum prospecting and exploitation activities are growing intensively.Especially in China,with the fastest economic growth in the world and shortage of petroleum resources,we are leading the practices of petroleum deep exploitation.Obviously,the risk of damage to the natural environment from these activities is high.Oil contamination in soils and groundwater is becoming a big issue along with pesticide pollution,which makes organic pollution prevention and control （OPPC） much more complex.In this paper,based on recent research on oil-contaminated soil at home and abroad,we make comments on the remediation technologies for polluted soil,emphasizing bioremediation techniques and degradation mechanisms in order to push forward research into bound organic pollution prevention and control （OPPC）,especially in China.
基金financial support provided by the National Nature Science Foundation of China(No.21576162,No.51578332,and No.21507085)the Shanghai Yangfan Program(14YF1401500)
文摘A BiVO_4 photoanode with exposed(040) facets was prepared to enhance its photoelectrochemical performance.The exposure of the(040) crystal planes of the BiVO_4 film was induced by adding NaCl to the precursor solution. The asprepared BiVO_4 photoanode exhibits higher solar-light absorption and charge-separation efficiency compared to those of an anode prepared without adding Na Cl. To our knowledge,the photocurrent density(1.26 m A cm^(-2) at 1.23 V vs. RHE) of as-prepared BiVO_4 photoanode is the highest according to the reports for bare BiVO_4 films under simulated AM1.5 G solar light, and the incident photon-to-current conversion efficiency is above 35% at 400 nm. The photoelectrochemical(PEC)water-splitting performance was also dramatically improvedwith a hydrogen evolution rate of 9.11 lmol cm^(-2) h^(-1), which is five times compared with the BiVO_4 photoanode prepared without NaCl(1.82 lmol cm^(-2) h^(-1)). Intensity-modulated photocurrent spectroscopy and transient photocurrent measurements show a higher charge-carrier-transfer rate for this photoanode. These results demonstrate a promising approach for the development of high-performance BiVO_4 photoanodes which can be used for efficient PEC water splitting and degradation of organic pollutants.
基金the Natural Science Foundation of Chongqing (CSTC2007BB6155)the Key Lab Visiting Scholar Foundation of Chongqing University (KLVF-2006-5)
文摘Azo dyes discharged in the environment are persistent organic pollutants （POPs）, which are very difficult to remove. We developed a microwave-assisted Fenton-like process to degrade methyl orange （MO）, an azo dye, with hydrogen peroxide （H2O2） catalyzed by chromium compounds coexisting with MO in the solution. Comparison between the Cr（Ⅲ）-H2O2 and Cr（Ⅵ）-H2O2 systems shows＂ that Cr（Ⅵ） has a stronger and more stable catalytical activity than Cr（Ⅲ）, and Cr（Ⅲ） is more susceptible to a change in the acidity or alkalinity of the reaction system. With a Cr（Ⅵ） concentration of 10 mmol L^-1 or a Cr（Ⅲ） concentration of 12 mmol L^-1 in the solution under the microwave irradiation of a power larger than 300 W for 3 min, 10 mmol L^-1 H2O2 can degrade more than 95% of 1 000 mg L^-1 methyl orange; when the microwave power is increased to 700 W, the same amount of H2O2 can degrade all methyl orange in the solution with the same amount of Cr（Ⅵ ） catalyst. Ultraviolet-visible spectrography indicates the cleavage of the azo bond in methyl orange after treatment, suggesting the potential o of this Fenton-like process to degrade azo dye POPs. Reusing waste chromium compounds coexisting with dyestuff in wastewater to catalyze the degradation of azo dyes could be a cost-effective technique for azo dyes and chromate manufacturers and/or users to treat their wastewater and prevent POPs from endangering the environment. This is of particula importance to controlling the water quality of the Three Gorges Reservoir.
