Bench-scale soil column experiments were carried out to evaluate the effectiveness of Cr（VI） bioremediation process in soils by using indigenous bacteria with the addition of bacteria nutrient media. Effects of part...Bench-scale soil column experiments were carried out to evaluate the effectiveness of Cr（VI） bioremediation process in soils by using indigenous bacteria with the addition of bacteria nutrient media. Effects of particle size, spray intensity, initial Cr（VI） concentration, circulation mode and soil depth on Cr（VI） remediation were studied. Results show that soils after 6 d remediation with spray intensity controlled in the range of 29.6-59.2 mL/min could well fulfill the requirement of concrete aggregate and roadbed material usage, for the leaching toxicity concentration of the Cr（VI） in treated soils under the chosen condition is far less than 5 mg/L The leaching toxicity and fractions of both hexavalent chromium and trivalent chromium from remediated soils were determined and compared with that of untreated soil. The results show that water soluble Cr（VI） declines from 1520.54 mg/kg to 0.68 mg/kg, exchangeable Cr（VI） decreases from 34.83 mg/kg to 0.01 mg/kg and carbonates-bonded Cr（V1） falls from 13.55 mg/kg to 0.68 mg/kg. Meanwhile, a corresponding increase in carbonate-bonded Cr（III）, Fe and Mn oxides-bonded Cr（III） and organic matter-bonded Cr（III） are found. It reveals that indigenous bacteria can leach out water soluble Cr（VI）, exchangeable Cr（VI） and carbonates-bonded Cr（VI） from contaminated soil followed by converting into carbonate-bonded Cr（III）, Fe and Mn oxides-bonded Cr（IlI）, organic matter-bonded Cr（III） and residual Cr（III）.展开更多
It has been studied restoration processes in oil products-polluted soils at high northern latitudes （the Murmansk region, Russia）. Mineral and organic fertilizers and a bacterial preparation （based on the local str...It has been studied restoration processes in oil products-polluted soils at high northern latitudes （the Murmansk region, Russia）. Mineral and organic fertilizers and a bacterial preparation （based on the local strains of hydrocarbon-oxidizing bacteria） were applied for restore polluted soils. Periods of removing OP （oil products） from soil were determined by the reduction of the pollutant concentration and by soil biological activities--the dynamics of bacteria number and CO2 emission from soil. The soil OP even at such a high concentration （as 10 L/m^2） had stimulated bacterial reproduction. In three summer month levels in the control variant without ameliorators of OP content decreased by 59% from the initial level, in the variant with mineral and organic fertilizers by 86%, in the variant with the bacterial preparation by 84%. Stimulating of indigenous microorganisms activity with additional nutrients was no less effective technique of OP-polluted soil bioremediation, than applying the bacterial preparation, which requires considerable financial investment. Moderately contaminated of OP soil is a source of additional carbon dioxide emission in the atmosphere. Pollution soil with OP caused for increasing of share of potentially pathogenic fungi in the fungal community.展开更多
Recent studies have revealed that concrete can be used as a media to contain As （arsenic） removed from drinking water. Concrete, which is a composite material, has been effective in solidifying hazardous wastes and ...Recent studies have revealed that concrete can be used as a media to contain As （arsenic） removed from drinking water. Concrete, which is a composite material, has been effective in solidifying hazardous wastes and contaminated soils. A research project was conducted to study the effects of uncontaminated soil and arsenic contaminated soil on the microstructure of concrete to qualitatively define the mechanisms of the encapsulation of soils containing inorganic material such as arsenic by application of solidification/stabilization technique. This research paper focused on studying the surface morphology of RPC （reactive powder concrete） containing soil.展开更多
Metal contamination in the environment is a global concern due to its high toxicity to living organisms and its worldwide distribution. The principal goal of this review is to examine the current strategies and techno...Metal contamination in the environment is a global concern due to its high toxicity to living organisms and its worldwide distribution. The principal goal of this review is to examine the current strategies and technologies for the remediation of metal- contaminated soils by metal-accumulating plants and assess the roles of arbnscular mycorrhizal （AM） fungi in remediation of soils under hyperaccumulator or non-accumulator plants. The use of plants to remove metals from the environment or reduce the toxicity, known as phytoremediation, is an environmentally sustainable and low cost remediation technology. The mechanisms of the use of hyperaccumulator plants for phytoremediation included solubilization of the metal in the soil matrix, the plant uptake of the metal, detoxification/chelation and sequestration, and volatilization. Recently, some ecologists have found that phytoremediation with the aids of mycorrhizae can enhance efficiency in the removal of toxic metals. AM fungi can facilitate the survival of their host plants growing on metal-contaminated land by enhancing their nutrient acquisition, protecting them from the metal toxicity, absorbing metals, and also enhancing phytostabilization and phytoextraction. Such information may be useful for developing phytoremediation program at metal-contaminated sites.展开更多
This paper presents a review of soil contamination resulting from e-waste recycling activities, with a special focus on China, where many data have been collected for a decade. Soils in the e-waste areas are often con...This paper presents a review of soil contamination resulting from e-waste recycling activities, with a special focus on China, where many data have been collected for a decade. Soils in the e-waste areas are often contaminated by heavy metals and organic compounds, mainly polycyclic aromatic hydrocarbons （PAHs）, polybrominated diphenyl ethers （PBDEs）, polychlorinated and polybrominated biphenyls （PCBs and PBBs）, dechlorane plus （DP）, hexabromocyclododecanes （HBCDs）, polychlorinated and polybrominated dibenzo- p-dioxins （PCDDs and PBDDs）, and polychlorinated and polybrominated dibenzofurans （PCDFs and PBDFs）, while other compounds, not systematically monitored, can be found as well. Pollutants are generally present in mixtures, so pollution situations are complex and diversified with a gradient of contamination from agricultural soils to hot spots at e-waste sites and mainly in open burning areas. It has been proved that pollutants were transferred to the food chain via rice in China, and that the population was threatened since high levels of various pollutants were detected in blood, placentas, hair, etc., of residents of e-waste sites. Eventually, soil remediation techniques are reviewed. Although there are many available techniques devoted to heavy metals and persistent organic pollutants, the current techniques for the e-waste sites, where these contaminants coexist, are very sparse. Phytoremediation has been investigated and co-cropping appears as a promising approach for the slightly contaminated agricultural soils. In some cases, different remediation techniques should be combined or trained, while the influence of coexisting contaminants and the removal sequence of contaminants should be considered. In hot spots, physical and chemical techniques should be used to reduce high pollution levels to prevent further pollutant dissemination. This review highlights the urgent needs for 1） characterization of pollution status in all the countries where e-wastes are recycled, 2） research on fate and toxicity of pollutant mixtures, and 3） development of combined techniques and strategies to remediate agricultural fields and hot spots of pollution.展开更多
Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils.This study aims to examine the growth,lead resistance and lead accumulat...Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils.This study aims to examine the growth,lead resistance and lead accumulation of mulberry(Morus alba L.)seedlings at four levels of soil lead contamination with or without biochar addition under normal or alternative partial root-zone irrigation(APRI).Methods We conducted a three-factor greenhouse experiment with biochar(with vs.without biochar addition),irrigation method(APRI vs.normal irrigation)and four levels of soil lead(0,50,200 and 800 mg·kg^(-1)).The performance of the seedlings under different treatments was evaluated by measuring growth traits,osmotic substances,antioxidant enzymes and lead accumulation and translocation.Important Findings The results reveal that mulberry had a strong ability to acclimate to soil lead contamination,and that biochar and APRI synergistically increased the biomass and surface area of absorption root across all levels of soil lead.The seedlings were able to resist the severe soil lead contamination(800 mg·kg^(-1) Pb)by adjusting glutathione metabolism,and enhancing the osmotic and oxidative regulating capacity via increasing proline content and the peroxidase activity.Lead ions in the seedlings were primarily concentrated in roots and exhibited a dose–effect associated with the lead concentration in the soil.Pb,biochar and ARPI interactively affected Pb concentrations in leaves and roots,translocation factor and bioconcentration.Our results suggest that planting mulberry trees in combination with biochar addition and APRI can be used to effectively remediate lead-contaminated soils.展开更多
Environmental pollution caused by metals, radionuclides and organic pollutants affects quality of the biosphere: soil, water and air.Currently, great efforts have been made to reduce, remove or stabilize contaminants ...Environmental pollution caused by metals, radionuclides and organic pollutants affects quality of the biosphere: soil, water and air.Currently, great efforts have been made to reduce, remove or stabilize contaminants in polluted sites. There has been increasing interest in phytoremediation—the use of plants to reduce concentration of pollutants or to render them harmless. This paper provides a brief review of recent progress in the research and practical application of phytoremediation techniques. Improvements in phytoremediation due to utilization of organic amendments, namely, agro- and industrial wastes(such as sugar beet residue, composted sewage sludge or molasses), biochar, humic substances, plant extracts and exudates are discussed, as well as their influences on soil structure and characteristics, plants growth and bioavailability of pollutants. Both plant-assisted phytoremediation and the use of natural materials in the absence of remediating plant are believed to be cost-effective and environmentally friendly approaches for soil cleanup. However,the characterization and quantification of a range of natural materials used in phytoremediation are essential in order to implement these approaches to practice.展开更多
There are many remediation techniques for organic contaminated soils,but relatively few of them are applicable to trace elementcontaminated soils.A field experiment was carried out to investigate assisted natural reme...There are many remediation techniques for organic contaminated soils,but relatively few of them are applicable to trace elementcontaminated soils.A field experiment was carried out to investigate assisted natural remediation(ANR) of an acid soil contaminated by As,Cd,Cu,Zn and Pb using one inorganic amendment,sugar beet lime(SL),and two organic amendments,biosolid compost(BC)and leonardeite(LE).The experiment was arranged in a completely randomized block design with four treatments in three replicates:1) a non-amended control(NA);2) SL amended at 30 Mg ha^(-1) year^(-1);3) BC amended at 30 Mg ha^(-1) year^(-1) and 4) LE amended at 20 Mg ha^(-1) year^(-1) plus SL amended at 10 Mg ha^(-1) year^(-1)(LESL).The amended plots received two doses of each amendment(DO2):one in October 2002 and another in October 2003.The plots were then divided in half into two subpolts and one subplot received another two doses of the same amendments(DO4) in October 2005 and October 2006.In 2011,the pH values of the amended soils were greater than that of the NA soil,with the SL-amended soil showing the highest pH.Total organic carbon(TOC) was also greater in the amended soil,and greater with DO4 than with DO2.Amendments reduced the concentrations of 0.01 mol L^(-1) CaCl_2-extractable Cd,Cu and Zn,especially in the SL-amended soil.Plant cover of colonizing vegetation was enhanced by amendments,but was independent of amendment doses.Changes in soil properties from 2003 to 2011 showed that the first amendment application of DO2 caused a high differentiation between all the amendment treatments and the NA treatment.After the second application of DO2,soil pH and TOC continued increasing slowly.Further two applications of amendments(DO4) caused differences only in the organic treatments.Plant cover increased over time in all the treatments including NA.It could be concluded that the slow and steady natural remediation of this soil could be enhanced by amendment application(ANR).展开更多
Arsenic （As） contamination has become the environment issue of global concern. In China, large area of farmland and the site soil were contaminated by As, which means that suitable remedying methods were urgently ne...Arsenic （As） contamination has become the environment issue of global concern. In China, large area of farmland and the site soil were contaminated by As, which means that suitable remedying methods were urgently needed. Phytoremediation, as one of environment-friendly soil remediation techniques developed in recent years, shows a bright future for the remediation of As contaminated soils. However, phytoremediation efficiency needs to be enhanced further because of low concentration of bio- available As in the soils. A triangle flask culture experiment was carried out to study the effects of functional species, isolated from As-polluted soils, that could improve As mobility from the soil. These species included two bacilli, B 1 and B2 （Breviba- cillus） and two fungi, F1 （Trichoderma）, F2 （Fusarium）. They could transform the concentration of As fractionation in the soil sterilized by the method of 6~Co-T ray. Through the experiment, the concentrations of non-specifically-sorbed and specifical- ly-sorbed As fractionation, and pH value of culture solution with inoculated treatment were higher than that with the control. Especially, the concentration of non-specifically-sorbed As fractionation in the treatment-inoculated species was 2 to 6 times higher than that of non-inoculation treatment. Moreover, two bacilli and two fungi could produce IAA, which was conducive to the plant survival when they were jointly used in remedying the As-contaminated soil.展开更多
基金Project(50925417) supported by the National Funds for Distinguished Young Scientist, ChinaProject(50830301) supported by the Key Program of National Natural Science Foundation of ChinaProject(51074191) supported by the National Natural Science Foundation of China
文摘Bench-scale soil column experiments were carried out to evaluate the effectiveness of Cr（VI） bioremediation process in soils by using indigenous bacteria with the addition of bacteria nutrient media. Effects of particle size, spray intensity, initial Cr（VI） concentration, circulation mode and soil depth on Cr（VI） remediation were studied. Results show that soils after 6 d remediation with spray intensity controlled in the range of 29.6-59.2 mL/min could well fulfill the requirement of concrete aggregate and roadbed material usage, for the leaching toxicity concentration of the Cr（VI） in treated soils under the chosen condition is far less than 5 mg/L The leaching toxicity and fractions of both hexavalent chromium and trivalent chromium from remediated soils were determined and compared with that of untreated soil. The results show that water soluble Cr（VI） declines from 1520.54 mg/kg to 0.68 mg/kg, exchangeable Cr（VI） decreases from 34.83 mg/kg to 0.01 mg/kg and carbonates-bonded Cr（V1） falls from 13.55 mg/kg to 0.68 mg/kg. Meanwhile, a corresponding increase in carbonate-bonded Cr（III）, Fe and Mn oxides-bonded Cr（III） and organic matter-bonded Cr（III） are found. It reveals that indigenous bacteria can leach out water soluble Cr（VI）, exchangeable Cr（VI） and carbonates-bonded Cr（VI） from contaminated soil followed by converting into carbonate-bonded Cr（III）, Fe and Mn oxides-bonded Cr（IlI）, organic matter-bonded Cr（III） and residual Cr（III）.
文摘It has been studied restoration processes in oil products-polluted soils at high northern latitudes （the Murmansk region, Russia）. Mineral and organic fertilizers and a bacterial preparation （based on the local strains of hydrocarbon-oxidizing bacteria） were applied for restore polluted soils. Periods of removing OP （oil products） from soil were determined by the reduction of the pollutant concentration and by soil biological activities--the dynamics of bacteria number and CO2 emission from soil. The soil OP even at such a high concentration （as 10 L/m^2） had stimulated bacterial reproduction. In three summer month levels in the control variant without ameliorators of OP content decreased by 59% from the initial level, in the variant with mineral and organic fertilizers by 86%, in the variant with the bacterial preparation by 84%. Stimulating of indigenous microorganisms activity with additional nutrients was no less effective technique of OP-polluted soil bioremediation, than applying the bacterial preparation, which requires considerable financial investment. Moderately contaminated of OP soil is a source of additional carbon dioxide emission in the atmosphere. Pollution soil with OP caused for increasing of share of potentially pathogenic fungi in the fungal community.
文摘Recent studies have revealed that concrete can be used as a media to contain As （arsenic） removed from drinking water. Concrete, which is a composite material, has been effective in solidifying hazardous wastes and contaminated soils. A research project was conducted to study the effects of uncontaminated soil and arsenic contaminated soil on the microstructure of concrete to qualitatively define the mechanisms of the encapsulation of soils containing inorganic material such as arsenic by application of solidification/stabilization technique. This research paper focused on studying the surface morphology of RPC （reactive powder concrete） containing soil.
基金Supported by the Research Grant Council,Hong Kong SAR,China
文摘Metal contamination in the environment is a global concern due to its high toxicity to living organisms and its worldwide distribution. The principal goal of this review is to examine the current strategies and technologies for the remediation of metal- contaminated soils by metal-accumulating plants and assess the roles of arbnscular mycorrhizal （AM） fungi in remediation of soils under hyperaccumulator or non-accumulator plants. The use of plants to remove metals from the environment or reduce the toxicity, known as phytoremediation, is an environmentally sustainable and low cost remediation technology. The mechanisms of the use of hyperaccumulator plants for phytoremediation included solubilization of the metal in the soil matrix, the plant uptake of the metal, detoxification/chelation and sequestration, and volatilization. Recently, some ecologists have found that phytoremediation with the aids of mycorrhizae can enhance efficiency in the removal of toxic metals. AM fungi can facilitate the survival of their host plants growing on metal-contaminated land by enhancing their nutrient acquisition, protecting them from the metal toxicity, absorbing metals, and also enhancing phytostabilization and phytoextraction. Such information may be useful for developing phytoremediation program at metal-contaminated sites.
文摘This paper presents a review of soil contamination resulting from e-waste recycling activities, with a special focus on China, where many data have been collected for a decade. Soils in the e-waste areas are often contaminated by heavy metals and organic compounds, mainly polycyclic aromatic hydrocarbons （PAHs）, polybrominated diphenyl ethers （PBDEs）, polychlorinated and polybrominated biphenyls （PCBs and PBBs）, dechlorane plus （DP）, hexabromocyclododecanes （HBCDs）, polychlorinated and polybrominated dibenzo- p-dioxins （PCDDs and PBDDs）, and polychlorinated and polybrominated dibenzofurans （PCDFs and PBDFs）, while other compounds, not systematically monitored, can be found as well. Pollutants are generally present in mixtures, so pollution situations are complex and diversified with a gradient of contamination from agricultural soils to hot spots at e-waste sites and mainly in open burning areas. It has been proved that pollutants were transferred to the food chain via rice in China, and that the population was threatened since high levels of various pollutants were detected in blood, placentas, hair, etc., of residents of e-waste sites. Eventually, soil remediation techniques are reviewed. Although there are many available techniques devoted to heavy metals and persistent organic pollutants, the current techniques for the e-waste sites, where these contaminants coexist, are very sparse. Phytoremediation has been investigated and co-cropping appears as a promising approach for the slightly contaminated agricultural soils. In some cases, different remediation techniques should be combined or trained, while the influence of coexisting contaminants and the removal sequence of contaminants should be considered. In hot spots, physical and chemical techniques should be used to reduce high pollution levels to prevent further pollutant dissemination. This review highlights the urgent needs for 1） characterization of pollution status in all the countries where e-wastes are recycled, 2） research on fate and toxicity of pollutant mixtures, and 3） development of combined techniques and strategies to remediate agricultural fields and hot spots of pollution.
基金funded by the Innovative Foundation of Mulberry and Silkworm Research Institute,Chinese Academy of Agricultural Sciences(16JK005).
文摘Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils.This study aims to examine the growth,lead resistance and lead accumulation of mulberry(Morus alba L.)seedlings at four levels of soil lead contamination with or without biochar addition under normal or alternative partial root-zone irrigation(APRI).Methods We conducted a three-factor greenhouse experiment with biochar(with vs.without biochar addition),irrigation method(APRI vs.normal irrigation)and four levels of soil lead(0,50,200 and 800 mg·kg^(-1)).The performance of the seedlings under different treatments was evaluated by measuring growth traits,osmotic substances,antioxidant enzymes and lead accumulation and translocation.Important Findings The results reveal that mulberry had a strong ability to acclimate to soil lead contamination,and that biochar and APRI synergistically increased the biomass and surface area of absorption root across all levels of soil lead.The seedlings were able to resist the severe soil lead contamination(800 mg·kg^(-1) Pb)by adjusting glutathione metabolism,and enhancing the osmotic and oxidative regulating capacity via increasing proline content and the peroxidase activity.Lead ions in the seedlings were primarily concentrated in roots and exhibited a dose–effect associated with the lead concentration in the soil.Pb,biochar and ARPI interactively affected Pb concentrations in leaves and roots,translocation factor and bioconcentration.Our results suggest that planting mulberry trees in combination with biochar addition and APRI can be used to effectively remediate lead-contaminated soils.
基金financially supported by the Polish Ministry of Science and Higher Education(No.DS 3500)
文摘Environmental pollution caused by metals, radionuclides and organic pollutants affects quality of the biosphere: soil, water and air.Currently, great efforts have been made to reduce, remove or stabilize contaminants in polluted sites. There has been increasing interest in phytoremediation—the use of plants to reduce concentration of pollutants or to render them harmless. This paper provides a brief review of recent progress in the research and practical application of phytoremediation techniques. Improvements in phytoremediation due to utilization of organic amendments, namely, agro- and industrial wastes(such as sugar beet residue, composted sewage sludge or molasses), biochar, humic substances, plant extracts and exudates are discussed, as well as their influences on soil structure and characteristics, plants growth and bioavailability of pollutants. Both plant-assisted phytoremediation and the use of natural materials in the absence of remediating plant are believed to be cost-effective and environmentally friendly approaches for soil cleanup. However,the characterization and quantification of a range of natural materials used in phytoremediation are essential in order to implement these approaches to practice.
基金supported by the Programa Operativo Feder de Andalucia 2007-2013 of Sapin (No.PAIDI AGR108)the Project of the Plan Nacional de Investigacion of Spain(No.AGL201123617)
文摘There are many remediation techniques for organic contaminated soils,but relatively few of them are applicable to trace elementcontaminated soils.A field experiment was carried out to investigate assisted natural remediation(ANR) of an acid soil contaminated by As,Cd,Cu,Zn and Pb using one inorganic amendment,sugar beet lime(SL),and two organic amendments,biosolid compost(BC)and leonardeite(LE).The experiment was arranged in a completely randomized block design with four treatments in three replicates:1) a non-amended control(NA);2) SL amended at 30 Mg ha^(-1) year^(-1);3) BC amended at 30 Mg ha^(-1) year^(-1) and 4) LE amended at 20 Mg ha^(-1) year^(-1) plus SL amended at 10 Mg ha^(-1) year^(-1)(LESL).The amended plots received two doses of each amendment(DO2):one in October 2002 and another in October 2003.The plots were then divided in half into two subpolts and one subplot received another two doses of the same amendments(DO4) in October 2005 and October 2006.In 2011,the pH values of the amended soils were greater than that of the NA soil,with the SL-amended soil showing the highest pH.Total organic carbon(TOC) was also greater in the amended soil,and greater with DO4 than with DO2.Amendments reduced the concentrations of 0.01 mol L^(-1) CaCl_2-extractable Cd,Cu and Zn,especially in the SL-amended soil.Plant cover of colonizing vegetation was enhanced by amendments,but was independent of amendment doses.Changes in soil properties from 2003 to 2011 showed that the first amendment application of DO2 caused a high differentiation between all the amendment treatments and the NA treatment.After the second application of DO2,soil pH and TOC continued increasing slowly.Further two applications of amendments(DO4) caused differences only in the organic treatments.Plant cover increased over time in all the treatments including NA.It could be concluded that the slow and steady natural remediation of this soil could be enhanced by amendment application(ANR).
基金supported by the National Natural Science Foundation of China (Grant Nos. 21307080 and 41101232)Shanghai Knowledge Service Platform (Grant No. ZF1224)Key Discipline Construction Projects of Shanghai Second Polytechnic University (Grant No. XXKYS1404)
文摘Arsenic （As） contamination has become the environment issue of global concern. In China, large area of farmland and the site soil were contaminated by As, which means that suitable remedying methods were urgently needed. Phytoremediation, as one of environment-friendly soil remediation techniques developed in recent years, shows a bright future for the remediation of As contaminated soils. However, phytoremediation efficiency needs to be enhanced further because of low concentration of bio- available As in the soils. A triangle flask culture experiment was carried out to study the effects of functional species, isolated from As-polluted soils, that could improve As mobility from the soil. These species included two bacilli, B 1 and B2 （Breviba- cillus） and two fungi, F1 （Trichoderma）, F2 （Fusarium）. They could transform the concentration of As fractionation in the soil sterilized by the method of 6~Co-T ray. Through the experiment, the concentrations of non-specifically-sorbed and specifical- ly-sorbed As fractionation, and pH value of culture solution with inoculated treatment were higher than that with the control. Especially, the concentration of non-specifically-sorbed As fractionation in the treatment-inoculated species was 2 to 6 times higher than that of non-inoculation treatment. Moreover, two bacilli and two fungi could produce IAA, which was conducive to the plant survival when they were jointly used in remedying the As-contaminated soil.
