蒽的高效降解菌的固定化小球的制备及其降解特性

Preparation of immobilized microorganisms degrading anthracene and its degradation characteristics

旨在利用固定化高效降解菌小球去除水中蒽,充分发挥累托石的吸附和生物降解的协同作用,以累托石、聚乙烯醇(PVA)、海藻酸钠(SA)作为固定化载体材料,硼酸和氯化钙作为交联剂,将蒽的高效降解菌包埋制备固定化微生物小球。考察了累托石用量、PVA投加量、海藻酸钠用量、氯化钙用量、微生物包埋量和交联时间等因素对微生物小球活性的影响,通过正交实验确定了微生物小球的最佳制备条件。结果表明,制备固定化微生物小球的最佳条件为:累托石2.5%,PVA 12%,SA0.3%,CaCl24%,交联时间28 h,微生物包埋量10%。对40 mg/L的蒽溶液,游离微生物在50 h后开始发挥明显的降解作用,经过68 h蒽的去除率达到35.65%;而固定化微生物小球经过9 h即可使蒽的去除率达到81.8%,23 h后蒽的去除率可达100%。固定化微生物小球对水中蒽的去除机理与吸附-降解工艺的机理类似,即固定化微生物小球类似于一个一体化的微型反应器,经过迟滞期后,在该反应器内同时发生吸附和降解作用。

Aiming at removing anthracene from water by immobilized predominant microorganisms and giving full play to synergistic effect of adsorption and biodegradation, rectorite, polyvinyl alcohol （PVA） and sodium alginate （SA） were used as immobilized carrier; boracic acid and calcium chloride were used as crosslinker to prepare immobilized microorganisms. The effects of dosage of rectorite, PVA, SA, CaCl2 , microorganisms＇amount wrapped and cross linking time on activity of the immobilized microorganisms were investigated. The optimal conditions to prepare immobilized microorganisms were determined through orthogonal tests. The results show that the optimal conditions are： rectorite 2.5% ,PVA 12%, SA 0.3%, CaCl2 4%, microorganisms＇ amount wrapped 10% and cross linking time 28 h, respectively. The free microorganisms can obviously degrade anthracene after 50 hours to solutions of 40 mg/L; the removal rate reaches 35. 65% after 68 hours. The removal rate of anthracene by immobilized microorganisms reaches 81.8% and 100% after 9 hours and 23 hours, respectively. The immobilized microorganisms is similar to a integrate micro-reactor in which the adsorption is simultaneous with biodegradation after a lag phase.