生物炭固定SM3菌剂的制备及其对三唑酮的降解研究

Preparation of biochar immobilized SM3 bacterial agent and degradation of triadimefon

针对环境中存在的三唑酮污染问题,本研究以生物炭为载体,一株三唑酮高效降解菌(Stenotrophomonas maltophilia)SM3为固定化菌种,采用吸附法制备成固定化菌剂。从4种生物炭中优选出具有比表面积较大、吸附性能好等特点的固定化载体,并对其制备条件进行优化,在此基础上,评估生物炭固定化菌剂的稳定性及其对三唑酮的降解效果。结果显示,4种生物炭中,油茶壳生物炭比表面积及孔隙大、官能团含量丰富、固定化菌剂对三唑酮降解效果优于其他3种,选择其作为固定化SM3菌的载体。单因子优化试验表明,在载体投加量20 mg·mL^(-1),SM3接菌量5%,固定温度30℃,固定时间36 h所制备的固定化菌剂对三唑酮的降解率可达93.27%。最佳条件下制备的固定化菌剂在4℃及室温(25~35℃)条件下存放28 d后对三唑酮的降解率仍可达到81.73%和58.18%,菌剂降解效果具有良好的稳定性。油茶壳生物炭固定化SM3菌剂的制备,为解决环境中三唑酮污染问题提供了良好的生物修复材料。

To address the problem of triadimefon contamination in the environment,this study prepared an immobilized bacterial agent by adsorption method using biochar as a carrier and an efficient triazolone degrading bacterium Stenotrophomonas maltophilia(SM3)as an immobilized strain.The immobilized carriers with characteristics of large specific surface area and good adsorption performance were preferably selected from four types of biochar,and their preparation conditions were optimized,based on which the stability of biochar immobilized bacterial agents and their degradation effects on triazolone were evaluated.The results showed that among these four,Camellia oleifera biochar had large specific surface area and pore space,rich functional groups,and better degradation effect of immobilized bacterial agent on triadimefon than the other three,and hence was selected as the carrier for immobilization of SM3 bacteria.The singlefactor optimization test showed that the degradation rate of triadimefon by the immobilized bacterial agent reached 93.27% when prepared at a carrier dosage of 20 mg·mL^(-1),SM3 inoculum of 5%,immobilization temperature of 30℃,and immobilization time of 36 h.The degradation rate of the immobilized bacterial agent prepared under the optimal conditions was reported reaching 81.73% and 58.18% for triadimefon after 28 d at 4℃,and at room temperatures(25-35℃),with the bacterial agent displaying good stability.The preparation of immobilized SM3 bacterial agent from Camellia oleifera biochar thus provides a good bioremediation material to reduce triadimefon pollution in the environment.