焦化厂高环PAHs污染土壤的电动-微生物修复

ELECTRO-BIOREMEDIATION OF COKING PLANT SOILS CONTAMINATED WITH HIGH-MOLECULAR POLYCYCLIC AROMATIC HYDROCARBONS

针对沈阳某焦化场地污染土壤中PAHs高环比例高、浓度高的特点,采用二维空间对称电场、功能性PAHs降解菌剂,进行了工程水平的电动-微生物联合修复试验(面积200 m2,极距1 m,土高0.7 m)。结果表明:极性切换形成的对称电场能使土壤pH保持在中性范围(pH在6.6~6.9),有利于微生物的生长代谢,提高了土壤中总PAHs和高环PAHs的去除率。在98 d时电动-微生物修复去除率达到51.2%,较微生物组提高了18.7%,削减负荷达40.6 g/(m3·d)。其中10种4—6环PAHs的去除率平均提高了20.9%,显示出电动-微生物技术修复焦化场地PAHs污染土壤的可行性及工程化应用前景。

Based on the high proportion and concentration of heavy PAHs in soil of Shenyang coking industrial site,functional PAHs-degrading bacteria reagent was prepared,the electrode control technique with 2-D symmetrical electric field was built,and electro-bioremediation technique was carried out( remediation area was 200 m3,distance between two electrodes was1 m,soil height was 0. 7 m). Results showed that the symmetrical electric field promoted the growth of microorganisms by maintaining the soil pH in the range of 6. 60 ~ 6. 95. Thus,these factors helped enhancing the degradation rate of total PAHs and heavy PAHs. The removal rate of total PAHs in the electro-bioremediation treatment reached 51. 2% during 98 days,which increased 18. 7% compared to the degrading bacteria treatment,and the removal rate among 10 kinds of 4—6 cyclic PAHs increased around 20. 9%. The pollution load declined to 40. 6 g /( m3·d). It was indicated the feasibility and engineering application prospect of electro-bioremediation for PAHs-contaminated soils especially in the coking industrial site.