The long-term oil exploitation in oil fields has led to pollution of surrounding soil, creating a serious ecological problem. In order to promote and improve the application of microbial remediation in oil contaminate...The long-term oil exploitation in oil fields has led to pollution of surrounding soil, creating a serious ecological problem. In order to promote and improve the application of microbial remediation in oil contaminated soil, experiment is carried out in polluted area in Zhongyuan Oilfield. In the experiment, indigenous microorganisms and other physical and chemical methods are employed, ryegrass is grown, and environmental factors in soil are regulated to degrade the oil and treat the polluted soil. Results show that when the average oil content in the soil is about 523.08 mg/kg, 65 days' remediation through plants and microorganisms could help bring the oil content down to 74.61 mg/kg, achieving a degradation rate of 85.74%; through salinity treatment, salt content in soil is reduced by 62.93-82.03% to 399-823 mg/kg from previous 2.22 g/kg. Through this experiment, the bioremediation method is improved and its effectiveness and feasibility are testified. The result has been applied in Zhongyuan Oilfield and has brought fair ecological and economic benefits, providing technical support to the treatment of contaminated soil of the same kind, and offering some insights to the treatment of soil contaminated by other organic pollutants.展开更多
Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils...Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils to estimate the uptake of organic and inorganic contaminants by plants from the oil contaminated soils.The experiment showed that the concentrations of some selected elements,such as B,Co and Ni in plants growing in the oil contaminated soils were significantly higher than those in plants growing in the uncontaminated control soil.The accumulation of metals in plants increased with plant biomass;however,the removal of metals by plants from the oil contaminated soils was not practical.展开更多
Graded modified Fenton’s （MF） oxidation is a strategy in which H 2 O 2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the sam...Graded modified Fenton’s （MF） oxidation is a strategy in which H 2 O 2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the same amount of H 2 O 2 continuously.The primary objective of the present study was to investigate whether a mild MF pre-oxidation such as a stepwise addition of H 2 O 2 can prevent sterilization and achieve a maximum degradation of tank oil in soil.Optimization experiments of graded MF oxidation were conducted using citric acid,oxalic acid and SOLV-X as iron chelators under different frequencies of H 2 O 2 addition.The results indicated that the activity order of iron chelates decreased as：citric acid （51%） SOLV-X （44%） oxalic acid （9%）,and citric acid was found to be an optimized iron chelating agent of graded MF oxidation.Three-time addition of H 2 O 2 was found to be favorable and economical due to decreasing total petroleum hydrocarbon removal from three time addition （51%） to five time addition （59%）.Biological experiments were conducted after graded MF oxidation of tank oil completed under optimum conditions mentioned above.After graded oxidation,substantially higher increase （31%） in microbial activity was observed with excessive H 2 O 2 （1470 mmol/L,the mol ratio of H 2 O 2：Fe 2＋ was 210：1） than that of non-oxidized soil.Removal efficiency of tank oil was up to 93% after four weeks.Especially,the oil fraction （C 10 –C 40 ） became more biodagradable after graded MF oxidation than its absence.Therefore,graded MF oxidation is a mild pretreatment to achieve an effective bioremediation of oil contaminated soil.展开更多
基金funded by The basic scientific research project fund of Chinese Academy of Geological Sciences (Code: YYWF201519)China Geology Survey Work Program (Code: 121201106000150006)+1 种基金The international cooperation project of Ministry of Science and Technology (Code: 2005DFA90200)Mine environment management project of Henan Provincial Department of Land and Resources
文摘The long-term oil exploitation in oil fields has led to pollution of surrounding soil, creating a serious ecological problem. In order to promote and improve the application of microbial remediation in oil contaminated soil, experiment is carried out in polluted area in Zhongyuan Oilfield. In the experiment, indigenous microorganisms and other physical and chemical methods are employed, ryegrass is grown, and environmental factors in soil are regulated to degrade the oil and treat the polluted soil. Results show that when the average oil content in the soil is about 523.08 mg/kg, 65 days' remediation through plants and microorganisms could help bring the oil content down to 74.61 mg/kg, achieving a degradation rate of 85.74%; through salinity treatment, salt content in soil is reduced by 62.93-82.03% to 399-823 mg/kg from previous 2.22 g/kg. Through this experiment, the bioremediation method is improved and its effectiveness and feasibility are testified. The result has been applied in Zhongyuan Oilfield and has brought fair ecological and economic benefits, providing technical support to the treatment of contaminated soil of the same kind, and offering some insights to the treatment of soil contaminated by other organic pollutants.
文摘Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils to estimate the uptake of organic and inorganic contaminants by plants from the oil contaminated soils.The experiment showed that the concentrations of some selected elements,such as B,Co and Ni in plants growing in the oil contaminated soils were significantly higher than those in plants growing in the uncontaminated control soil.The accumulation of metals in plants increased with plant biomass;however,the removal of metals by plants from the oil contaminated soils was not practical.
基金supported by the Program of In-ternational S&T Cooperation(No.2010 DFA 94550,2010KW-24-1)the National Natural Science Founda-tion of China(No.50830303)+1 种基金the Major Science and Technology Program for Water Pollution Control and Treatment(No.2009ZX07317-007-001)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0853)
文摘Graded modified Fenton’s （MF） oxidation is a strategy in which H 2 O 2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the same amount of H 2 O 2 continuously.The primary objective of the present study was to investigate whether a mild MF pre-oxidation such as a stepwise addition of H 2 O 2 can prevent sterilization and achieve a maximum degradation of tank oil in soil.Optimization experiments of graded MF oxidation were conducted using citric acid,oxalic acid and SOLV-X as iron chelators under different frequencies of H 2 O 2 addition.The results indicated that the activity order of iron chelates decreased as：citric acid （51%） SOLV-X （44%） oxalic acid （9%）,and citric acid was found to be an optimized iron chelating agent of graded MF oxidation.Three-time addition of H 2 O 2 was found to be favorable and economical due to decreasing total petroleum hydrocarbon removal from three time addition （51%） to five time addition （59%）.Biological experiments were conducted after graded MF oxidation of tank oil completed under optimum conditions mentioned above.After graded oxidation,substantially higher increase （31%） in microbial activity was observed with excessive H 2 O 2 （1470 mmol/L,the mol ratio of H 2 O 2：Fe 2＋ was 210：1） than that of non-oxidized soil.Removal efficiency of tank oil was up to 93% after four weeks.Especially,the oil fraction （C 10 –C 40 ） became more biodagradable after graded MF oxidation than its absence.Therefore,graded MF oxidation is a mild pretreatment to achieve an effective bioremediation of oil contaminated soil.
