海藻酸钙-活性炭纤维固定化生物小球的强化除苯性能

Benzene Removal by Calcium Alginate and Activated Carbon Fiber Immobilized Bio-Beads

在传统海藻酸钙固定化过程中加入活性炭纤维作为改性载体,以苯系物(BTEX)降解菌为对象,制备了海藻酸钙-活性炭纤维固定化生物小球(MB),并研究了MB微观结构及强化除苯性能.结果表明:所制备的MB直径为2～4,mm,其表面通透、孔道致密,孔径均一(约为200,μm),并可多次重复应用.MB强化除苯过程主要是吸附和生物降解共同作用的结果,且去除速率呈现由快速到慢速两个阶段,均符合一级动力学规律.微生物接种量为6.89,mg/mL(包埋载体溶液)时,MB结构稳定性最好,强化除苯效果最佳.不同接种量条件下,苯生物降解的平均半衰期为64 h,高于游离态BTEX降解菌.

Immobilized bio-beads（MBs）in gel were produced with BTEX mixtures acclimated microbes as biodegra-dation target,and calcium alginate and activated carbon fiber（ACF）as improved encapsulated carrier.Scanning elec-tron microscopy was used to detect the microstructure of MB,and the performance of enhanced biodegradation of benzene was further studied.Results show that MB has loose interface,intense and homogeneous holes with the aper-ture of 200 μm,and well reusability for eight times at least with the diameter of 2—4,mm.Removal of benzene is based on synergistic adsorption combined with biodegradation and the removal rate changes from the higher level to the lower level,both of which are accord with the one-order kinetics principle.MB has the optimal structural stability and the best benzene removal performance when the immobilization cell density is 6.89,mg/mL（encapsulation solu-tion）.The half-life of benzene-degradation activity for MB is 64 h on an average,longer than that of free cells.