垃圾渗滤液处理菌株的筛选及处理工艺条件的优化

Screening of strains for landfill leachate treatment and optimization of treatment conditions

为了改善城市生活垃圾经填埋处理产生的渗滤液污染问题,以某生活垃圾卫生填埋场采集的土样作为菌源,筛选出适于降解垃圾渗滤液的优势菌株,采用Plackett-Burman实验设计法筛选出影响菌株降解垃圾渗滤液的主要因素,在此基础上运用最陡坡实验法接近最大响应值区域,通过响应面法求取最优降解条件。结果标明:经分子生物学鉴定,适于降解本文垃圾渗滤液的优势菌株为镰刀菌(Fusarium chlamydosporum),命名为菌株Fusarium chlamydosporum TJPU02;影响菌株降解垃圾渗滤液的3个主要因素为蛋白胨质量浓度、接种量和葡萄糖质量浓度;最优降解条件为蛋白胨4.3mg/mL、接种量6.44%、葡萄糖9.2mg/mL,此条件下COD降解率理论预测值为85.95%,实验值为85.76%,二者基本吻合,说明所筛选的优势菌株Fusarium chlamydosporum TJPU02对垃圾渗滤液具有显著降解效果,存在广阔应用前景。

In order to improve the leachate pollution caused by landfill disposal of municipal solid waste,the soil samples collected from some waste sanitary landfill were used as the source of bacteria to screen the dominant strain suitable for degrading landfill leachate. Plackett-Burman(PB) experiment was used to screen the main factors affecting the degradation of landfill leachate by strains. Then the path of steepest ascent was taken to approach the optimal response surface area of degradation conditions based on the results of PB experiment. Finally,the optimal degradation conditions were obtained by the response surface method(RSM). The results show that the dominant strain is identified as Fusarium chlamydosporum by molecular biology and named as Fusarium chlamydosporum TJPU02. Three main factors affecting the degradation of landfill leachate by Fusarium chlamydosporum TJPU02 are peptone concentration,inoculum size and glucose concentration. The optimal degradation conditions are peptone 4.3 mg/mL,inoculum size 6.44%,glucose 9.2 mg/mL. The mean value of COD degradation rate obtained from the verification experiments is 85.76% under these optimal conditions,which is in good agreement with the theoretical predicted value of 85.95%. It illustrates that the dominant strain Fusarium chlamydosporum TJPU02 exhibites significant degradation effect on landfill leachate and has broad application prospects.