摘要
为了使石油降解效果达到最佳,以筛选的6种石油降解菌为实验对象,通过牛津杯拮抗实验,选择无拮抗作用的菌株复配优化构建4组复合菌群,并以NaOH-球磨共改性制得的壳基生物炭为载体,制备了吸附-降解相结合的高效石油降解固定化菌剂,并通过扫描电镜和红外光谱对固定化菌剂进行表征。结果表明,当芽孢杆菌、不动杆菌、四会假单胞菌和蜡样芽孢杆菌4株菌最佳体积比为1∶3∶4∶1时,在温度30℃、转速120 r/min的摇床中培养7 d,对石油-无机盐培养基样品中石油降解率为60.36%,且降解动力学符合Monod方程。响应面分析确定最佳固定化菌剂制备条件为:温度33℃,吸附时间8.83 h,菌接种体积分数2.8%,共改性生物炭加入量0.1 g,摇床转速100 r/min;在此条件下获得了具有良好降解性能的固定化菌剂,固定细菌量为1.141×10^(11)CFU/g。扫描电镜和红外光谱分析结果表明:固定化菌剂具有良好的疏水性及复合菌群在生物炭上的定殖;经60 d的修复试验,投加固定化菌剂的石油降解率为91.23%,比添加共改性生物炭和石油降解复合菌群分别提高了11.83和42.83百分点,说明共改性生物炭固定化微生物用于修复石油污染土壤具有显著效果。
To achieve the best oil degradation effect,six screened oil degrading bacteria were used as experimental objects.Through the Oxford cup antagonistic experiment,four groups of composite bacterial communities were constructed by selecting the optimized complex strains without antagonistic effects.The shell-based biochar modified by NaOH ball milling was used as the carrier to prepare an efficient oil degradation immobilized microbial agent for adsorption and degradation,and this agent was also characterized by scanning electron microscopy and infrared spectroscopy.The results show that under conditions where the optimal volume ratio of Bacillus subtilis,Acinetobacter baumannii,Pseudomonas aeruginosa and Bacillus cereus is 1∶3∶4∶1,and these four strains are cultured in the shaking incubator with a temperature of 30℃and a rotational speed of 120 r/min for 7 days,the degradation rate of petroleum in the inorganic salt culture medium sample can reach 60.36%,and the degradation kinetics is in line with the Monod equation.Based on response surface analysis,the optimal preparation conditions for the immobilized microbial agent are determined as follows:temperature 33℃,adsorption time 8.83 h,microbial inoculation volume fraction 2.8%,co-modified biochar dosage 0.1 g,and rotational speed 100 r/min.Under these conditions,the immobilized bacterial agent with good degradation performance was obtained,achieving an immobilized bacteria count of 1.141×10^(11) CFU/g.The scanning electron microscopy and infrared spectroscopy analysis results indicate that the immobilized microbial agent has good hydrophobicity and effective colonization of complex bacterial communities on biochar.After 60 days of remediation experiments,the petroleum degradation rate achieved by immobilized microbial agents is 91.23%,which has increased by 11.83 and 42.83 percentage points compared to the treantments with co-modified biochar and petroleum composite bacterial groups,respectively,indicating that co-modified biochar immobilized microorganisms have significant effects on the remediation of petroleum-contaminated soil.
作者
马晓婉
李海红
韦泽华
MA Xiaowan;LI Haihong;WEI Zehua(College of Environmental and Chemical Engineering,Xi'an Polytechnic University,Xi'an 710048,China)
出处
《石油学报(石油加工)》
北大核心
2025年第5期1430-1441,共12页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
陕西省科技厅项目(2024NC-YBXM-240)
西安市科技局项目(23NYGG0045)基金资助。
关键词
石油污染土壤
菌群构建
固定化
生物炭
响应曲面优化
petroleum-contaminated soil
bacterial community construction
immobilization
biochar
response surface optimization
