地下环境中铁氧化物生物异化还原耦合降解硝基苯的影响因素研究

通过静态实验模拟地下水厌氧环境,研究了碳源、电子受体、初始微生物量和硝基苯浓度等因素对地下环境中微生物异化铁还原作用耦合降解硝基苯的影响。实验选取乙酸铵、葡萄糖、柠檬酸铵为碳源,针铁矿、赤铁矿为电子受体,进行异化铁还原协同耦合降解硝基苯。结果表明：乙酸铵为碳源时硝基苯的降解率最高为78.5%;针铁矿作电子受体时硝基苯降解效果比赤铁矿好,且0.3 mg·L-1效果最好;微生物量对耦合体系中硝基苯降解率有影响但并不显著,最适宜的初始微生物量为4×108cells·mL-1;硝基苯质量浓度在50～150 mg·L-1时,硝基苯浓度与降解率呈负相关,其中对50 mg·L-1的初始硝基苯质量浓度降解效果最好。因此,碳源和电子受体对地下环境中微生物异化铁还原作用耦合降解硝基苯具有重要的影响。

Influences of coupled degradation of nitrobenzene by iron oxides bacterial dissimilatory reduction in groundwater

Static experiments were designed to investigate the influencing factors of nitrobenzene degradation coupled to bacterial dissimilatory iron reduction in subsurface environment.Ammonium acetate,glucose and ammonium citrate were taken as carbon sources;goethite and hematite were taken as electron acceptors.The result indicated that nitrobenzene could be degraded the best when ammonium acetate was used as carbon source and the degradation rate was 78.5%.The reaction took place better in goethite system than in hematite system,in which 0.3 mg·L-1was the best.Microbial biomass had small influence on nitrobenzene degradation and the most suitable amount was 4×108 cells·mL-1.The degradation rate was negatively correlated with nitrobenzene concentration and the optimum concentration was 50 mg·L-1.