For years, biochar has been successfully used for the remediation of polycyclic aromatic hydrocarbons(PAHs) in contaminated soils, not only for improving their removal from soil but also for reducing their uptake by c...For years, biochar has been successfully used for the remediation of polycyclic aromatic hydrocarbons(PAHs) in contaminated soils, not only for improving their removal from soil but also for reducing their uptake by crops. However, the underlying mechanism of biochar application reducing PAH uptake and accumulation in winter wheat remains unclear. Pot trials were conducted on a PAH-contaminated soil amended with bamboo biochar, coconut shell biochar,and maize straw biochar(MSB) for an entire growth period of winter wheat. Compared with no biochar control(CK), application of the three types of biochar significantly(P < 0.01) reduced grain PAH concentration, total equivalent concentration(TEC), and incremental lifetime cancer risk(ILCR), indicating that biochar application, especially MSB, reduced the risk of exposure to PAHs in wheat grain. Furthermore, all three types of biochar significantly(P < 0.05)reduced PAH uptake and accumulation in wheat roots and stems, probably because biochar application enhanced the degradation of PAHs in the rhizosphere soil. Compared with CK, application of the three types of biochar significantly(P < 0.05) reduced the concentration of PAHs in the rhizosphere soil by15.9%–33.7%. It was found that the degradation rate of high-molecular-weight(HMW) PAHs(5-and 6-ring PAHs) was significantly(P < 0.05) higher than that of low-molecular-weight(LMW) PAHs(2–4-ring PAHs) regardless of the type of biochar used. Additionally, all three types of biochar significantly increased the relative abundance of the dominant bacterial phyla and genera in soil. Redundancy and correlation analyses also showed that there was a strong correlation between the removal rate of PAHs and dominant bacteria in the rhizosphere soil. This study indicated that biochar effectively reduced the health risk from dietary exposure to PAHs in wheat grains by increasing the abundance of bacteria related to PAH degradation, promoting the biodegradation of PAHs in the rhizosphere soil, and consequently reducing PAH uptake by wheat.展开更多
There has long been a great concern with growing anthropogenic contaminants and their ecological and toxicological effects on living organisms and the surrounding environment for decades.Metabolomics,a functional read...There has long been a great concern with growing anthropogenic contaminants and their ecological and toxicological effects on living organisms and the surrounding environment for decades.Metabolomics,a functional readout of cellular activity,can capture organismal responses to various contaminant-related stressors,acquiring direct signatures to illustrate the environmental behaviours of anthropogenic contaminants better.This review entails the application of metabolomics to profile metabolic responses of environmental organisms,e.g.animals(rodents,fish,crustacean and earthworms)and microorganisms(bacteria,yeast and microalgae)to different anthropogenic contaminants,including heavy metals,nanomaterials,pesticides,pharmaceutical and personal products,persistent organic pollutants,and assesses their ecotoxicological impacts with regard to literature published in the recent five years.Contaminant-induced metabolism alteration and up/down-regulation of metabolic pathways are revealed in typical organisms.The obtained insights of variations in global metabolism provide a distinct understanding of how anthropogenic contaminants exert influences on specific metabolic pathways on living organisms.Thus with a novel ecotechnique of environmental metabolomics,risk assessments of anthropogenic contaminants are profoundly demonstrated.展开更多
Compacted clay possesses a low water permeability and has been widely used in geo-environmental facilities such as landfill cover systems.Recent studies revealed the potential applications of compacted biochar-amended...Compacted clay possesses a low water permeability and has been widely used in geo-environmental facilities such as landfill cover systems.Recent studies revealed the potential applications of compacted biochar-amended clay(BAC)as an alternative landfill cover soil.However,the effects of biochar on the soil water retention curves(SWRCs)of clay at low suction are not known.This study can help fill this knowledge gap by measuring the wetting and drying SWRCs of clay and BAC(20%biochar).Soils were compacted in instrumented soil columns and subjected to a wetting and drying cycle,and soil water content and suction were measured along with the soil depth.BAC was saturated faster when compared with clay.Upon drying,the soil water content of clay at 65 mm depth dropped to almost zero,while about 5%of water was retained in BAC.It showed that biochar increased the soil water retention capacity of compacted clay upon drying.SWRCs showed that biochar-clay composite possesses a higher soil water retention capacity at a low soil suction range(<1000 kPa)compared with clay alone.It revealed the benefits of using compacted biochar-clay composite as a hydraulic barrier to minimize desiccation-induced cracks and potentially promote its serviceability,especially in arid and semi-arid regions.The composite is also a carbon sink material that can reduce landfill gas emissions and pollutant leaching.展开更多
Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural hous...Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.展开更多
Sewage discharge could be a major source of polycyclic aromatic hydrocarbons （PAHs） in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works （SCISTW and STSTW） in Hong Kong, adopted chemically ...Sewage discharge could be a major source of polycyclic aromatic hydrocarbons （PAHs） in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works （SCISTW and STSTW） in Hong Kong, adopted chemically enhanced primary treatment and biological treatment, respectively. This study aimed at （1） determining the removal efficiencies of PAHs, （2） comparing the capabilities in removing PAHs, and （3） characterizing the profile of each individual PAHs, in the two sewage treatment plants （STPs）. Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes （from 301 ± 255 and 307 ± 217 ns/L to 14.9 ± 12.1 and 63.3 ± 54.1 ng/L in STSTW and SCISTW, respectively）. It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal effidency 94.4% ± 4.12% us. 79.2% ± 7.48% （p 〈 0.05）. The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples （dewatered sludge contained 92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively） than liquid samples （final efffluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively）. Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs （1.85 and 39.3 ks/year, respectively for the two STPs） being discharged into Hone Kon coastal waters, which would be an environmental concern.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 42077325 and 41571456)the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2019JZ-25)。
文摘For years, biochar has been successfully used for the remediation of polycyclic aromatic hydrocarbons(PAHs) in contaminated soils, not only for improving their removal from soil but also for reducing their uptake by crops. However, the underlying mechanism of biochar application reducing PAH uptake and accumulation in winter wheat remains unclear. Pot trials were conducted on a PAH-contaminated soil amended with bamboo biochar, coconut shell biochar,and maize straw biochar(MSB) for an entire growth period of winter wheat. Compared with no biochar control(CK), application of the three types of biochar significantly(P < 0.01) reduced grain PAH concentration, total equivalent concentration(TEC), and incremental lifetime cancer risk(ILCR), indicating that biochar application, especially MSB, reduced the risk of exposure to PAHs in wheat grain. Furthermore, all three types of biochar significantly(P < 0.05)reduced PAH uptake and accumulation in wheat roots and stems, probably because biochar application enhanced the degradation of PAHs in the rhizosphere soil. Compared with CK, application of the three types of biochar significantly(P < 0.05) reduced the concentration of PAHs in the rhizosphere soil by15.9%–33.7%. It was found that the degradation rate of high-molecular-weight(HMW) PAHs(5-and 6-ring PAHs) was significantly(P < 0.05) higher than that of low-molecular-weight(LMW) PAHs(2–4-ring PAHs) regardless of the type of biochar used. Additionally, all three types of biochar significantly increased the relative abundance of the dominant bacterial phyla and genera in soil. Redundancy and correlation analyses also showed that there was a strong correlation between the removal rate of PAHs and dominant bacteria in the rhizosphere soil. This study indicated that biochar effectively reduced the health risk from dietary exposure to PAHs in wheat grains by increasing the abundance of bacteria related to PAH degradation, promoting the biodegradation of PAHs in the rhizosphere soil, and consequently reducing PAH uptake by wheat.
基金funded by the National Natural Science Foundation of China(51809004 and 51679002)the Shenzhen Science and Technology Innovation Program(JCYJ20180503182122539 and JCYJ20200109140616774).
文摘There has long been a great concern with growing anthropogenic contaminants and their ecological and toxicological effects on living organisms and the surrounding environment for decades.Metabolomics,a functional readout of cellular activity,can capture organismal responses to various contaminant-related stressors,acquiring direct signatures to illustrate the environmental behaviours of anthropogenic contaminants better.This review entails the application of metabolomics to profile metabolic responses of environmental organisms,e.g.animals(rodents,fish,crustacean and earthworms)and microorganisms(bacteria,yeast and microalgae)to different anthropogenic contaminants,including heavy metals,nanomaterials,pesticides,pharmaceutical and personal products,persistent organic pollutants,and assesses their ecotoxicological impacts with regard to literature published in the recent five years.Contaminant-induced metabolism alteration and up/down-regulation of metabolic pathways are revealed in typical organisms.The obtained insights of variations in global metabolism provide a distinct understanding of how anthropogenic contaminants exert influences on specific metabolic pathways on living organisms.Thus with a novel ecotechnique of environmental metabolomics,risk assessments of anthropogenic contaminants are profoundly demonstrated.
基金the Collaborative Research Fund provided by the Research Grants Council of Hong Kong(HKUST6/CRF/12R)Shenzhen Science and Technology Program(KCXFZ20201221173601003).
文摘Compacted clay possesses a low water permeability and has been widely used in geo-environmental facilities such as landfill cover systems.Recent studies revealed the potential applications of compacted biochar-amended clay(BAC)as an alternative landfill cover soil.However,the effects of biochar on the soil water retention curves(SWRCs)of clay at low suction are not known.This study can help fill this knowledge gap by measuring the wetting and drying SWRCs of clay and BAC(20%biochar).Soils were compacted in instrumented soil columns and subjected to a wetting and drying cycle,and soil water content and suction were measured along with the soil depth.BAC was saturated faster when compared with clay.Upon drying,the soil water content of clay at 65 mm depth dropped to almost zero,while about 5%of water was retained in BAC.It showed that biochar increased the soil water retention capacity of compacted clay upon drying.SWRCs showed that biochar-clay composite possesses a higher soil water retention capacity at a low soil suction range(<1000 kPa)compared with clay alone.It revealed the benefits of using compacted biochar-clay composite as a hydraulic barrier to minimize desiccation-induced cracks and potentially promote its serviceability,especially in arid and semi-arid regions.The composite is also a carbon sink material that can reduce landfill gas emissions and pollutant leaching.
基金Natural Science Foundation Committee of China(No.41390240,41130754,and 41161160559)National Basic Research Program of China(No.2014CB441101)+1 种基金Science&Technology Basic Special Fund(No.2013FY111100-04)Global Alliance for Clean Cookstoves under PR-15-39809
文摘Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.
基金Financial support from the Drainage Services Department,the Government of the Hong Kong SAR(nos.DEMP/2011/04,DEMP/2014/03 and DEMP/2015/01)the Open Science Research Fund of State Key Laboratory in Marine Pollution(no.OSRF/0001)+1 种基金the Start-up Research Grant for Newly Recruited Professors/(Research)Chair ProfessorsThe Education University of Hong Kong(no.RG24/13-14R)is gratefully acknowledged
文摘Sewage discharge could be a major source of polycyclic aromatic hydrocarbons （PAHs） in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works （SCISTW and STSTW） in Hong Kong, adopted chemically enhanced primary treatment and biological treatment, respectively. This study aimed at （1） determining the removal efficiencies of PAHs, （2） comparing the capabilities in removing PAHs, and （3） characterizing the profile of each individual PAHs, in the two sewage treatment plants （STPs）. Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes （from 301 ± 255 and 307 ± 217 ns/L to 14.9 ± 12.1 and 63.3 ± 54.1 ng/L in STSTW and SCISTW, respectively）. It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal effidency 94.4% ± 4.12% us. 79.2% ± 7.48% （p 〈 0.05）. The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples （dewatered sludge contained 92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively） than liquid samples （final efffluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively）. Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs （1.85 and 39.3 ks/year, respectively for the two STPs） being discharged into Hone Kon coastal waters, which would be an environmental concern.
