Abstract:

Immobilized microorganism was prepared by adsorption method，by choosing thirteen kinds of natural materials（eight organic carriers and five inorganic carriers），including YJ-5，YJ-6，YJ-7，YJ-8，WJ-1，WJ-4 and WJ-5，as immobilized carrier，and crude oil from Shengli oil field as response substance. The oil degradation performance of immobilized microbial prepared by each material was tested and the materials with better performance were characterized. The results showed that YJ-5 is the best immobilized material and followed by YJ-7，and the best inorganic carrier was WJ-1. Both bacteria adsorption amount and oil degradation rate were considered to determine the optimal preparation condition of YJ-5 immobilized microorganism，which were carrier amount 10mL，inoculation content 20%，immobilized time 15 h，temperature 30 ℃ and rotate speed 160r/min. Under this condition，the seven days oil degradation rate reached 61%，which is 40% higher than that with free bacteria. The specific surface area and pore distribution（BET）indicated that there was only simple mesoporous structure in YJ-7，YJ-5 and WJ-1. Scanning electrometry microscopy（SEM）results showed that there were mainly cylindrical holes in YJ-5，it immobilized bacteria through surface adsorption，its carrier structure would get loose and bacteria shed after degradation.