The contamination of soils by polycyclic aromatic hydrocarbons （PAHs） is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bi...The contamination of soils by polycyclic aromatic hydrocarbons （PAHs） is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-β-cyclodextrin （MCD） on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% （W/W） MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH- degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% （W/W） MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases （p 〈 0.05） in the average well color development （AWCD） obtained by the BIOLOG Eco plate assay, Shannon-Weaver index （H） and Simpson index （λ） compared with the controls, implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.展开更多
New pollutants in remote regions have become a global issue of concern.This study collected soil,lichen,moss,and air samples from the high mountain area of southeastern Tibet to analyze the altitude pollution distribu...New pollutants in remote regions have become a global issue of concern.This study collected soil,lichen,moss,and air samples from the high mountain area of southeastern Tibet to analyze the altitude pollution distribution of 16 polycyclic aromatic hydrocarbons(PAHs)and the related influencing factors.The results revealed that the average levels ofΣ6PAH in soil,moss,lichen,and air samples were 46.8 ng/g dry weight(dw),140.6 ng/g dw,712.0 ng/g dw,and 60.1 ng/m^(3),respectively.Naphthalene and phenanthrene were the most abundant individual isomers,and 2–4 rings PAHs accounted for approximately 90%of the totalΣPAH concentration in the samples.Source apportionment analysis highlighted the impact of atmospheric PAH inputs on this region.Octanol/air distribution factor(K_(oa)),altitude,plant coverage,and soil organic matter were the key determinants of PAH concentration along the altitudinal gradient.Across all the soil sampling sites,the average contribution of the forest filter effect(FFE)was greater than that of the mountain cold trapping effect based on the principal component analysis and multiple linear regression.The findings of this study strengthened the reasons for the preferential accumulation of organic pollutants in the high-altitude mountainous area,and provided important insights for effective environmental strategies of new pollutants.展开更多
Solubilizing experiments were carried out to evaluate the ability of biodiesel to remove polycyclic aromatic hydrocarbons(PAHs)from highly contaminated manufactured gas plant(MGP)and PAHs spiked soils with hydroxyprop...Solubilizing experiments were carried out to evaluate the ability of biodiesel to remove polycyclic aromatic hydrocarbons(PAHs)from highly contaminated manufactured gas plant(MGP)and PAHs spiked soils with hydroxypropyl-β-cyclodextrin(HPCD)and tween 80 as comparisons.Biodiesel displayed the highest solubilities of phenanthrene(420.7 mg·L^(-1)),pyrene(541.0 mg·L^(-1)),and benzo(a)pyrene(436.3 mg·L^(-1)).These corresponded to several fold increases relative to 10%HPCD and tween 80.Biodiesel showed a good efficiency for PAH removal from the spiked and MGP soils for both low molecular weight and high molecular weight PAHs at high concentrations.Biodiesel was the best agent for PAH removal from the spiked soils as compared with HPCD and tween 80;as over 77.9%of individual PAH were removed by biodiesel.Tween 80 also showed comparable capability with biodiesel for PAH solubilization at a concentration of 10%for the spiked soils.Biodiesel solubilized a wider range of PAHs as compared to HPCD and tween 80 for the MPG soils.At PAH concentrations of 229.6 and 996.9 mg·kg^(-1),biodiesel showed obvious advantage over the 10%HPCD and tween 80,because it removed higher than 80%of total PAH.In this study,a significant difference between PAH removals from the spiked and field MGP soils was observed;PAH removals from the MGP soil by HPCD and tween 80 were much lower than those from the spiked soil.These results demonstrate that the potential for utilizing biodiesel for remediation of highly PAH-contaminated soil has been established.展开更多
The extracellular enzyme secretion and biodegradation of polycyclic aromatic hydrocarbons （PAHs） were studied in agitated and shallow stationary liquid cultures of Phanerochaete chrysosporium. Veratryl alcohol and T...The extracellular enzyme secretion and biodegradation of polycyclic aromatic hydrocarbons （PAHs） were studied in agitated and shallow stationary liquid cultures of Phanerochaete chrysosporium. Veratryl alcohol and Tween80 were added to cultures as lignin peroxidase （LIP） and manganese peroxidase （MnP） inducer, respectively. Shallow stationary cultures were suitable for the production of enzyme, whereas agitated cultures enhanced overall biodegradation by facilitating interphase mass transfer of PAHs into aqueous phases. The use of a LiP stimulator, veratryl alcohol, did not increase PAH degradation but significantly enhanced LiP activity. In contrast, Tween80 increased both MnP secretion and PAH degradation in shallow stationary cultures. On the other hand, high PAH degradation was observed in agitated cultures in the absence of detectable LiP and MnP activities. The results suggested that extracellular peroxidase activities are not directly related to the PAH degradation, and the increased solubility rather than enzyme activity may be more important in the promotion of PAH degradation.展开更多
The consequence of polycyclic aromatic hydrocarbons(PAHs)in the environment is of great concern.The hydrophobic properties of PAHs significantly impact phase distribution causing limited bioavailability.Enhanced biode...The consequence of polycyclic aromatic hydrocarbons(PAHs)in the environment is of great concern.The hydrophobic properties of PAHs significantly impact phase distribution causing limited bioavailability.Enhanced biodegradation has been extensively carried out by surfactants and the redeployment effect was recognized.However,the quantitative relationship concerning the impact of solids was rarely reported.A batch of biphasic tests were carried out by introducing Mycobacterium vanbaalenii PYR-1 and hydroxypropyl-β-cyclodextrin(HPCD)into a mixture of phenanthrene solution and various glass beads(GB37-63,GB105-125,and GB350-500).The comparative results demonstrated that HPCD had little effect on microbial growth and was not degradable by bacterium.A model was proposed to describe the biodegradation process.The regression results indicated that the partition coefficient kd(1.234,0.726 and 0.448 L·g–1)and the degradation rate k(0 mmol·L^(–1):0.055,0.094,and 0.112;20 mmol·L^(–1):0.126,0.141,and 0.156;40 mmol·L^(–1):0.141,0.156 and 0.184 d^(–1))were positively and negatively correlated with the calculated total surface area(TSA)of solids,respectively.Degradation enhanced in the presence of HPCD,and the enhancing factor f was calculated(20 mmol·L^(–1):15.16,40.01,and 145.5;40 mmol·L^(–1):13.29,37.97,and 138.4),indicating that the impact of solids was significant for the enhancement of biodegradation.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province (No. BK2009016)the Chinese National Environmental Protection Special Funds for Scientific Research on Public Causes (No. 2010467016)the National High Technology Research and Development Program (863) of China (No. 2007AA061101)
文摘The contamination of soils by polycyclic aromatic hydrocarbons （PAHs） is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-β-cyclodextrin （MCD） on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% （W/W） MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH- degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% （W/W） MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases （p 〈 0.05） in the average well color development （AWCD） obtained by the BIOLOG Eco plate assay, Shannon-Weaver index （H） and Simpson index （λ） compared with the controls, implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.
基金supported by the National Natural Science Foundation of China(No.22021003)the Zhejiang Provincial Natural Science Foundation,China(No.LY23B070001).
文摘New pollutants in remote regions have become a global issue of concern.This study collected soil,lichen,moss,and air samples from the high mountain area of southeastern Tibet to analyze the altitude pollution distribution of 16 polycyclic aromatic hydrocarbons(PAHs)and the related influencing factors.The results revealed that the average levels ofΣ6PAH in soil,moss,lichen,and air samples were 46.8 ng/g dry weight(dw),140.6 ng/g dw,712.0 ng/g dw,and 60.1 ng/m^(3),respectively.Naphthalene and phenanthrene were the most abundant individual isomers,and 2–4 rings PAHs accounted for approximately 90%of the totalΣPAH concentration in the samples.Source apportionment analysis highlighted the impact of atmospheric PAH inputs on this region.Octanol/air distribution factor(K_(oa)),altitude,plant coverage,and soil organic matter were the key determinants of PAH concentration along the altitudinal gradient.Across all the soil sampling sites,the average contribution of the forest filter effect(FFE)was greater than that of the mountain cold trapping effect based on the principal component analysis and multiple linear regression.The findings of this study strengthened the reasons for the preferential accumulation of organic pollutants in the high-altitude mountainous area,and provided important insights for effective environmental strategies of new pollutants.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20707030)the National High Technology Research and Development Program(863 program)of China(No.2008AA06Z331)the National Basic Research Program(973 Program)of China(No.2004CB418506).
文摘Solubilizing experiments were carried out to evaluate the ability of biodiesel to remove polycyclic aromatic hydrocarbons(PAHs)from highly contaminated manufactured gas plant(MGP)and PAHs spiked soils with hydroxypropyl-β-cyclodextrin(HPCD)and tween 80 as comparisons.Biodiesel displayed the highest solubilities of phenanthrene(420.7 mg·L^(-1)),pyrene(541.0 mg·L^(-1)),and benzo(a)pyrene(436.3 mg·L^(-1)).These corresponded to several fold increases relative to 10%HPCD and tween 80.Biodiesel showed a good efficiency for PAH removal from the spiked and MGP soils for both low molecular weight and high molecular weight PAHs at high concentrations.Biodiesel was the best agent for PAH removal from the spiked soils as compared with HPCD and tween 80;as over 77.9%of individual PAH were removed by biodiesel.Tween 80 also showed comparable capability with biodiesel for PAH solubilization at a concentration of 10%for the spiked soils.Biodiesel solubilized a wider range of PAHs as compared to HPCD and tween 80 for the MPG soils.At PAH concentrations of 229.6 and 996.9 mg·kg^(-1),biodiesel showed obvious advantage over the 10%HPCD and tween 80,because it removed higher than 80%of total PAH.In this study,a significant difference between PAH removals from the spiked and field MGP soils was observed;PAH removals from the MGP soil by HPCD and tween 80 were much lower than those from the spiked soil.These results demonstrate that the potential for utilizing biodiesel for remediation of highly PAH-contaminated soil has been established.
基金This work was supported by the National Natural Science Foundation of China(No.20677024).
文摘The extracellular enzyme secretion and biodegradation of polycyclic aromatic hydrocarbons （PAHs） were studied in agitated and shallow stationary liquid cultures of Phanerochaete chrysosporium. Veratryl alcohol and Tween80 were added to cultures as lignin peroxidase （LIP） and manganese peroxidase （MnP） inducer, respectively. Shallow stationary cultures were suitable for the production of enzyme, whereas agitated cultures enhanced overall biodegradation by facilitating interphase mass transfer of PAHs into aqueous phases. The use of a LiP stimulator, veratryl alcohol, did not increase PAH degradation but significantly enhanced LiP activity. In contrast, Tween80 increased both MnP secretion and PAH degradation in shallow stationary cultures. On the other hand, high PAH degradation was observed in agitated cultures in the absence of detectable LiP and MnP activities. The results suggested that extracellular peroxidase activities are not directly related to the PAH degradation, and the increased solubility rather than enzyme activity may be more important in the promotion of PAH degradation.
文摘The consequence of polycyclic aromatic hydrocarbons(PAHs)in the environment is of great concern.The hydrophobic properties of PAHs significantly impact phase distribution causing limited bioavailability.Enhanced biodegradation has been extensively carried out by surfactants and the redeployment effect was recognized.However,the quantitative relationship concerning the impact of solids was rarely reported.A batch of biphasic tests were carried out by introducing Mycobacterium vanbaalenii PYR-1 and hydroxypropyl-β-cyclodextrin(HPCD)into a mixture of phenanthrene solution and various glass beads(GB37-63,GB105-125,and GB350-500).The comparative results demonstrated that HPCD had little effect on microbial growth and was not degradable by bacterium.A model was proposed to describe the biodegradation process.The regression results indicated that the partition coefficient kd(1.234,0.726 and 0.448 L·g–1)and the degradation rate k(0 mmol·L^(–1):0.055,0.094,and 0.112;20 mmol·L^(–1):0.126,0.141,and 0.156;40 mmol·L^(–1):0.141,0.156 and 0.184 d^(–1))were positively and negatively correlated with the calculated total surface area(TSA)of solids,respectively.Degradation enhanced in the presence of HPCD,and the enhancing factor f was calculated(20 mmol·L^(–1):15.16,40.01,and 145.5;40 mmol·L^(–1):13.29,37.97,and 138.4),indicating that the impact of solids was significant for the enhancement of biodegradation.
