聚乙烯醇二次交联固定锰氧化细菌的试验

Test of Manganese-Oxidizing Bacteria Immobilized in Polyvinyl Alcohol by Second CrossLinking Process

针对传统聚乙烯醇一硼酸法固定化颗粒粘连膨胀、机械强度差、硼酸对细菌具有毒性等缺点，该文采用二次交联法固定锰氧化细菌。分别考察了聚乙烯醇（PVA）浓度、二次交联pH值、二次交联时间、添加剂、包菌量对固定细菌膨胀性、机械强度、活性的影响。结果表明聚乙烯醇浓度的提高有利于机械强度的提高并降低膨胀率，但是会降低固定细菌活性；二次交联pH在8—10时机械强度较好，pH为8和9时活性最高；二次交联时间应大于8h，不宜超过48h；碳酸钙、活性炭有利于降低膨胀率，但是碳酸钙会降低细菌活性，活性炭会使机械强度降低；当包菌量大于4％时机械强度有明显的下降趋势，锰去除率随着包菌量的增加而增加。

To overcome the shortcomings of expansion, low mechanical strength and toxicity in traditional PVA- boric acid method, the manganese-oxidizing bacteria were embedded in polyvinyl alcohol made by secondary cross-linking method. In the sin- gle-factor experiment, the effect of concentration of PVA, pH value, time in secondary cross linking process, different co-composite matters and the amount of embedded bacteria on the immobilized manganese-oxidizing bacteria were studied. The results show that improving the concentration of PVA is benefit for the mechanical strength, and lowers bacteria activity. When pH value in secondary process changes in 8-10, PVA has better mechanical strength and the highest bacteria activity, when pH is 8 or 9. The time of the secondary process should not be shorter than 8 h and longer than 48 h. Activated carbon is useful for improving bioactivity and calci- um carbonate for mechanical strength. The manganese removing rate improves with the amount of embedded bacteria.