活性炭含量对PVA-SA固定化小球处理氯苯微污染废水的影响

Effects of Activated Carbon in Sodium Alginate and Polyvinylacohol Immobilization Pellets of Penicillium sp. on Chlorobenzene Removal

以海藻酸钠(SA)、聚乙烯醇(PVA)联合作为包埋剂,包埋一株高效降解氯苯的青霉菌,分析复合凝胶小球的最佳配比及不同的活性炭添加量对包埋小球的机械强度、酸碱稳定性、传质性能及氯苯降解性能的影响.结果表明,复合凝胶小球最佳配比为w(PVA)∶w(SA)∶w(Ca Cl2)=6%∶2%∶2%;活性炭的加入能增强固定化小球的机械强度,且在活性炭质量分数为1%时强化效果最理想;PVA-SA小球在酸性溶液中的稳定性比在碱性溶液中高,且稳定性随着活性炭含量的增加而增强;在温度30℃、p H=6、氯苯初始质量浓度为30 mg/L的条件下,不同活性炭含量的固定化小球均能提高氯苯降解速度,活性炭质量分数为1%、1.5%时在72 h内能达到80%以上的氯苯去除率.综合评价,在固定化微生物过程中添加1%活性炭,达到改善所得包埋小球的综合性能的目的,提高降解氯苯速率.

By embedding activated carbon and Penicillium sp.with the combination of sodium alginate(SA)and polyvinyl alcohol(PVA)as embedding agents,the ingredients of compound gel balls were optimized,and the associated mechanical strength,environmental stability,mass transfer performance and chlorobenzene removal under different levels of activated carbon contents were also assessed.Experimental results showed that the optimal mix ratio of the three compounds for composite gel beads was w(PVA)∶w(SA)∶w(CaCl2)=6%∶2%∶2%.The addition of activated carbon was showed to be able to enhance the mechanical strength of immobilized pellets and the maximum mechanical strength was observed at the addition of1%activated carbon.The stability of PVA-SA balls under acidic condition was higher than that of alkaline condition and their stability was increased with the increase of activated carbon contents.The addition of activated carbon increased the removal ability of chlorobenzene under the conditions of30℃,pH6,chlorobenzene initial concentration of30mg/L.The removal percentage of chlorobenzene reached over80%when activated carbon content was1%or1.5%at72h.In conclusion,the addition of1%activated carbon in the immobilization PVA-SA balls of Penicillium sp.Improved the overall performance of the embedded pellets,with significant increase in mechanical strength,environmental stability,mass transfer performance and removal efficiency of chlorobenzene in water.