腐植酸改性生物质电厂灰固定化微生物修复石油烃污染土壤

以生物质电厂灰为载体，用腐植酸对其改性后，负载石油烃降解菌形成固定化菌剂对原油污染土壤进行修复，其中对生物质电厂灰改性的最佳条件以及固定化菌剂对原油污染土壤的修复效果进行了考察。结果表明:生物质电厂灰改性的最佳条件为:电厂灰粒径10~40目，固液比1∶1，改性时间4 h，改性后孔状结构增多且表面粗糙，有利于微生物的附着，固定的微生物数量可达1.5×109 CFU/g。进行60 d的修复后，固定化菌剂对污染土壤中石油烃的降解率达到51.9%，比游离菌提高了25.0%，对长链正构烷烃、芳香烃及胶质的降解率分别提高了9.6%、31.7%和37.5%。固定化生物质电厂灰的应用使石油烃降解菌得到保护和支撑，提高了土壤基础呼吸速率和土壤酶活性，实现了石油烃的高效降解。因此，腐植酸改性生物质电厂灰是一种在石油污染土壤修复方面具有应用潜力的微生物固定化材料。

BIOREMEDIATION OF CRUDE OIL IN CONTAMINATED SOIL BY MICROORGANISMS IMMOBILIZED WITH HUMIC ACID-MODIFIED BIOFUEL ASH

In this study, humic acid-modified biofuel ash was used as the carrier to immobilize the petroleum degrading bacteria for remediating the crude oil contaminated soil, and the best modification conditions of biofuel ash and the remediation effect of immobilized bacteria were investigated. The results showed that the optimum conditions of modified biofuel ash were: 10~40 mesh for the particle size, 1∶1 for the liquid ratio and 4 h for the modification time. After modification, the biofuel ash had rich pore-like structures and rough surface, which were favorable to the adsorption of bacteria and the immobilized number reached 1.5×109 CFU/g. After 60 days’ remediation, the removal efficiency of total petroleum hydrocarbon was 51.9%, which was higher than free bacteria by 25.0%, and the removal efficiency of long-chain n-alkanes, aromatic hydrocarbons and colloids was improved by 9.6%, 31.7% and 37.5%, respectively. The application of immobilized biofuel ash protected and supported the petroleum degrading bacteria, enhanced the basal respiration rate and the soil enzyme activity, thus achieved highly efficient degradation of petroleum hydrocarbon in soil. Therefore, humic acid-modified biofuel ash is a promising immobilization material in the field of petroleum contaminated soil remediation.