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探讨了固定床除Cr工艺以油菜秆为微生物生长的缓释碳源,含SRB的混合微生物和油菜秆对Cr（Ⅵ）的还原和固定的共同作用。动态实验分2阶段开展：初始2周的驯化阶段和梯度增加Cr（Ⅵ）浓度的除Cr实验阶段。除Cr实验中,间歇对固定床出水pH、氧化还原电位、SO42-及硫化物浓度、DOC、Cr（Ⅵ）浓度进行测试,实验结束后对固定床中固体产物进行SEM、EDS和XPS等分析。结果表明,油菜秆固定床处理模拟含Cr（Ⅵ）废水效果明显。当进水Cr（Ⅵ）浓度ρ[Cr（Ⅵ）]〈19.52 mg/L时,出水Cr（Ⅵ）和Cr（Ⅲ）浓度均低于排放标准（0.05 mg/L）;Cr（Ⅵ）被还原为Cr（Ⅲ）,Cr（Ⅲ）以氢氧化物的形式沉淀附着于油菜秆和其它固体物质之上。分析认为,油菜秆在固定床处理模拟含Cr（Ⅵ）废水中所起的作用主要包括3方面（作为微生物生长的缓释碳源;吸附Cr（Ⅵ）,降低其对微生物的毒性;作为Cr（Ⅲ）矿化产物的沉淀附着界面）;Cr（Ⅵ）主要通过SRB的直接作用及H2S的作用被还原为Cr（Ⅲ）;以油菜秆为碳源的固定床处理Cr（Ⅵ）的浓度上限介于15.05～19.52mg/L之间。“,”This study discussed the combined effects of rape straw and sulfate reducing bacteria（SRB） on Cr（Ⅵ） treatment in fixed-bed reactor with rape straw as carbon source.Two-stage experiments—domestication and Cr（Ⅵ） treatment,were designed.During the Cr（Ⅵ） treatment stage,pH,Eh,concentrations of SO42-,S2-,DOC,Cr（Ⅵ） and Cr（Ⅲ） for the effluent water were monitored constantly.After the second stage,solid products in the reactor were analyzed by using SEM and XPS.The results showed that fixed-bed reactor with rape straw filled was efficient in treating Cr（Ⅵ） wastewater： when Cr（Ⅵ） concentration of influent water was below 19.52 mg/L,the concentrations of Cr（Ⅵ） and Cr（Ⅲ） in effluent water were both below the discharge standard（0.5 mg/L）;Cr（Ⅵ） was reduced to Cr（Ⅲ）,which was precipitated with the form of hydroxides.This study indicates that rape straw in the fix-bed reactor enhances the reduction and immobilization of Cr（Ⅵ） by slow releasing carbon source for SRB and other functional bacteria,adsorbing Cr,and precipitating Cr（Ⅲ） hydroxides.Cr（Ⅵ） is reduced both by using SRB and H2S.In fixed-bed reactor with rape straw as carbon source,the upper limit of tolerable Cr（Ⅵ） concentration for functional microbes is between 15.05 and 19.52 mg/L.