聚乙烯醇固定锰氧化细菌的试验研究

Experimental Study on the Immobilization of Manganese-oxidizing Bacteria by Polyvinyl Alcohol

在传统聚乙烯醇-硼酸固定法的基础上,利用不同交联剂与聚乙烯醇二次交联进行聚乙烯醇固定锰氧化细菌的试验研究,以克服传统交联法水溶膨胀性的缺点。结果表明:磷酸氢二钠作为交联剂时,固定细菌的活性较高,但是其固定细菌的机械强度较差,限制了磷酸氢二钠的应用;硫酸钠、硝酸钠、氯化钙作为交联剂时,可以改善聚乙烯醇的水溶膨胀性,固定细菌的机械强度较高,但传质效果差,导致固定细菌的活性较低,对此可通过向聚乙烯醇载体中加入活性炭,以改善其传质性,提高固定细菌的活性;而戊二醛因其具有毒性,且固定细菌的机械强度差,不宜作为交联剂。

Manganese-oxidizing bacteria are immobilized in polyvinyl alcohol balls that are cross-linked with boric acid and then processed with other second cross linking agents to overcome the shortcomings of disso- lution and expansion in traditional PVA-boric acid method, such as sodium hydrogen phosphate, sodium sulfate, sodium nitrate, calcium chloride and glutaraldehyde. The results show that the immobilized bacteria that are cross-linked with sodium hydrogen phosphate have high biological activity, but their mechanical strength is poor and limits their application. The application of sodium sulfate, sodium nitrate and calcium chloride as the second cross linking agents improves the mechanical strength and reduces the weakness of dissolution and expansion; but the poor mass transfer performance results in the lower biological activity which should be improved by mixing the activated carbon. The glutaraldehyde agent is not suitable for cross linking with PVA for its biological toxicity and low mechanical strength of immobilized bacteria.