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
Present study was conducted to clarify soil pH and temperature influence on different atrazine bioremediation techniques. For this purpose, sodium citrate, Arthrobactor sp. strain DNS10, sawdust and animal manure were...Present study was conducted to clarify soil pH and temperature influence on different atrazine bioremediation techniques. For this purpose, sodium citrate, Arthrobactor sp. strain DNS10, sawdust and animal manure were selected to clarify their atrazine remediation efficiency under pH 5, 7 and 9 and temperatures 20, 30 and 40℃, respectively. Results showed that atrazine remediation was generally optimized at pH 7 and 30℃ for all the treatments except sodium citrate as soil treated with sawdust was not temperature dependant, but at pH 5 remediation process was determined slower. Atrazine remediation in soil with no additional amendment was only 34%, while in soil treated with sawdust, DNS10, sodium citrate and animal manure were 75.17%, 89%, 74.17% and 76.83% at optimized pH and temperature. Overall atazine removal rate was significantly（≥0.01） higher with increasing in temperature at all the selected pH.展开更多
Heavy metals were evaluated in the soils of grain fields in Hailun City Experimental Research Station-Chinese Academy of Sciences （CAS）. Four categories of the soil samples were chosen from the fields after 19 years...Heavy metals were evaluated in the soils of grain fields in Hailun City Experimental Research Station-Chinese Academy of Sciences （CAS）. Four categories of the soil samples were chosen from the fields after 19 years of treatment with chemicals, no fertilizer, organic manure, and organic manure combined with chemical fertilizer. The study revealed a prevalence of significantly high concentrations of Cu, Zn and Pb in organic manure combined with chemical fertilizer in the grain fields of black soils. The concentrations of Cu and Zn in no fertilizer treatment, chemical treatment, and organic treatment also exceeded the permissible limits However, the concentrations of rig and As were found to be within the safe limits in all treatments.展开更多
Di-n-butyl phthalate (DBP),one of phthalate acid esters (PAEs),was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the se...Di-n-butyl phthalate (DBP),one of phthalate acid esters (PAEs),was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the sediment. The sediment sample was incubated with an initial concentration of DBP of 100 mg/L for 5 d. The biodegradation rate of DBP was detected using HPLC and the degraded products were analyzed by GC/MS. Subsequently,the microbial diversity of the enrichment culture was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results reveal that almost 100% of DBP is degraded after merely 3 d,generating two main degraded products:mono-butyl phthalate (MBP) and 9-octadecenoic acid. After a six-month enrichment period under the pressure of DBP,the dominant family in the final enrichment culture is clustered with the Comamonas sp.,the remaining are affiliated with Sphingomonas sp.,Hydrogenophaga sp.,Rhizobium sp.,and Acidovorax sp. The results show the potential of these bacteria to be used in the bioremediation of DBP in the environment.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）.
基金Supported by the University Science and Technology Innovation Team Construction Projects of Heilongjiang Province(2013 TD003)
文摘Present study was conducted to clarify soil pH and temperature influence on different atrazine bioremediation techniques. For this purpose, sodium citrate, Arthrobactor sp. strain DNS10, sawdust and animal manure were selected to clarify their atrazine remediation efficiency under pH 5, 7 and 9 and temperatures 20, 30 and 40℃, respectively. Results showed that atrazine remediation was generally optimized at pH 7 and 30℃ for all the treatments except sodium citrate as soil treated with sawdust was not temperature dependant, but at pH 5 remediation process was determined slower. Atrazine remediation in soil with no additional amendment was only 34%, while in soil treated with sawdust, DNS10, sodium citrate and animal manure were 75.17%, 89%, 74.17% and 76.83% at optimized pH and temperature. Overall atazine removal rate was significantly（≥0.01） higher with increasing in temperature at all the selected pH.
基金Supported by TWAS (The Third World Academy of Sciences)-CAS (The Chinese Academy of Sciences) Fellowship for Visiting Scholarsthe Chinese Academy of Sciences (KZCX2-YW-408-3)
文摘Heavy metals were evaluated in the soils of grain fields in Hailun City Experimental Research Station-Chinese Academy of Sciences （CAS）. Four categories of the soil samples were chosen from the fields after 19 years of treatment with chemicals, no fertilizer, organic manure, and organic manure combined with chemical fertilizer. The study revealed a prevalence of significantly high concentrations of Cu, Zn and Pb in organic manure combined with chemical fertilizer in the grain fields of black soils. The concentrations of Cu and Zn in no fertilizer treatment, chemical treatment, and organic treatment also exceeded the permissible limits However, the concentrations of rig and As were found to be within the safe limits in all treatments.
基金Project(50621063) supported by the National Nature Science Foundation of ChinaProject(NCET-06-0691) supported by the Program for New Century Excellent Talents in University
文摘Di-n-butyl phthalate (DBP),one of phthalate acid esters (PAEs),was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the sediment. The sediment sample was incubated with an initial concentration of DBP of 100 mg/L for 5 d. The biodegradation rate of DBP was detected using HPLC and the degraded products were analyzed by GC/MS. Subsequently,the microbial diversity of the enrichment culture was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results reveal that almost 100% of DBP is degraded after merely 3 d,generating two main degraded products:mono-butyl phthalate (MBP) and 9-octadecenoic acid. After a six-month enrichment period under the pressure of DBP,the dominant family in the final enrichment culture is clustered with the Comamonas sp.,the remaining are affiliated with Sphingomonas sp.,Hydrogenophaga sp.,Rhizobium sp.,and Acidovorax sp. The results show the potential of these bacteria to be used in the bioremediation of DBP in the environment.
