腐殖酸与活性污泥对污染土壤联合修复研究

Combined Remediation of Contaminated Soil by Humic Acid and Activated Sludge

采用正交试验的方法,研究了表面活性剂溶出和微生物降解联合作用对重金属铜、锌、铅和多环芳烃菲、萘、芘人工老化污染土壤的修复效率。选择腐殖酸为表面活性剂,强化微生物对有机污染物的降解性能,将高效降解菌的降解能力有效地发挥出来;用驯化的活性污泥为土壤生物修复剂,强化腐殖酸对重金属的洗提作用,旨在降低重金属和多环芳烃在土壤中的污染作用,提高修复效率。结果表明,接种2.0%活性污泥,温度为35℃,pH值为6.5,腐殖酸加入量为5mg/g的土壤为最佳修复条件,在此条件下菲、萘、芘的总修复率分别为73.4%,80.5%和68.2%;重金属离子Cu2+,Zn2+,Pb3+的总修复率分别为75.5%,64.2%和71.7%。添加腐殖酸和驯化活性污泥可明显提高土壤中重金属和多环芳烃的修复效率,表明化学溶出与生物降解同时作用于复合污染土壤具有较好的协同作用。

An orthogonal experiment was conducted to study the effects of chemical dissolution and biodegradation on the remediation efficiency for artificially contaminated soil by heavy metals Cu,Zn and Pb,as well as phenanthrene,naphthalene and pyrene.Humic acid（HA） was selected as eluent to strengthen the performance of microbial degradation of organic pollutants,which can effectively improve the degradation efficiency of degrading strain.Activated sludge was selected as degradation agent to strengthen the HA elution of heavy metals.The goal of this study was to reduce the polluted effect of heavy metals and polycyclic aromatic hydrocarbons（PAHs） in soil and increase the remediation efficiency.Results showed that the optimal conditions for remediation were temperature 35 ℃,pH 6.5,inoculation amount of activated sludge 2.0% and humic acid 5 mg/g.In this condition,the remediation efficiencies for phenanthrene,naphthalene and pyrene were 73.4%,80.5% and 68.2%,and for Cu2＋,Zn2＋ and Pb3＋,75.5%,64.2% and 71.7%,respectively.The addition of HA and activated sludge could significantly enhance the remediation of contaminated soil.It showed well the synergistic effect between chemical dissolution and biodegradation to remediate contaminated soil.