改善污泥脱水性能的丝状真菌的分离及其促进污泥脱水的机制初探

探讨污泥中丝状真菌对污泥脱水性能的影响及其机制,对生物法强化污泥脱水技术的发展具有重要意义.本研究从剩余污泥中分离筛选可以提高污泥脱水性能的丝状真菌,并分析其改善污泥脱水性能的具体机制.结果表明,在剩余污泥中存在着可以促进污泥脱水性能改善的丝状真菌,从中分离筛选出1株毛霉属的真菌Mucor circinelloides ZG-3,该菌对改善污泥脱水性能具有良好的效果.该丝状真菌处理剩余污泥过程中污泥的脱水性能改善效果主要受到接种方式、接种浓度和污泥含固率的影响,其最适接种方式为菌丝体接种,最适接种浓度为10%,最适污泥含固率约为4%.在最适条件下处理污泥可使污泥比阻降低75.1%,显著改善污泥的脱水性能,并且处理后污泥溶液的COD值约为310 mg·L-1,处理后的污泥仍具有良好的沉降性能.M.circinelloides ZG-3处理剩余污泥过程中,污泥脱水性能的改善主要与污泥胞外聚合物(EPS)的降解和污泥p H的降低有关.因此,采用M.circinelloides ZG-3处理剩余污泥是一种非常有潜力的新型污泥调理技术.

Isolation of Filamentous Fungi Capable of Enhancing Sludge Dewaterability and Study of Mechanisms Responsible for the Sludge Dewaterability Enhancement

To study the influence of filamentous fungi on the sludge dewaterability is very significant for the development of biological treatment methods for enhancing sludge dewaterability. In this study, filamentous fungi capable of enhancing sludge dewaterability were isolated from sewage sludge and the related mechanisms responsible for the sludge dewaterability enhancement were investigated. A filamentous fungus Mucor circinelloides ZG-3 was successfully isolated from sludge, and sludge dewaterability could be drastically improved by this fungus. Further study revealed that the enhancement of sludge dewaterability was influenced by inoculation method, inoculum size and solid content of sludge. The optimal inoculation method was mycelia inoculation, the optimal inoculum size was 10%, and the optimal solid content of sludge was about 4%. Under the optimized conditions, the specific resistance to filtration (SRF) of sludge could be decreased by 75.1% after being treated by M. circinelloides ZG-3. After the treatment, the COD value of sludge supernatant was only 310 mg·L^-1, and the treated sludge still exhibited good settleability. During the treatment of sewage sludge by M. circinelloides ZG-3, the mechanisms responsible for the sludge dewaterability enhancement included the degradation of sludge extracellular polymeric substances (EPS) and the decrease of sludge pH. Therefore, the treatment of sewage sludge using M. circinelloides ZG-3 is a useful and novel method for sludge conditioning.