Towards understanding the dewatering mechanism of sewage sludge improved by bioleaching processing.
He Liu, Shuo Yang, Jiasheng Shi, Xiaoyu Xu, Hongbo Liu, Bo Fu. 全文下载
School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China
School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, China
Jiangsu Key Laboratory of Anaerobic Biotechnology, 214122 Wuxi, China
Bioleaching by sulfur oxidizing bacteria has been regarded as a novel dewatering process for the sludge treatment. Since the bioleaching process is a comprehensive biological and chemical process for sludge treatment, it is necessary to explore the dewatering mechanism of sewage sludge improved by bioleaching.The bioleached sludge showed a significant difference with the control sludge, mostly through a considerable reduction of pH (to 3.92) and an improved specific resistance to filtration (SRF), which reduced to 5.31×1010 m/kg after 72 h treatment. Separate sulfuric acid addition and Fe2+ addition did not result in significant decrease of sludge resistance filtration, indicating that the chemical acidification and Fe2+ addition are not the deciding factors for the improvement by bioleaching. The extracellular polymeric substances in bioleached sludge decreased considerably, with the protein and polysaccharide reduced by 97.42% and 76.00%, respectively. During the bioleaching process, the number of microbial genuses in the bioleached sludge gradually decreased and the dominant bacterial genus (Acidimicrobium ferrooxidans) shifted from 7.48% to 26.49% at the end of bioleaching. While many factors influence the dewaterability of the sludge, the bio-substitution which led to the decrease of EPS is the deciding factor for the dewaterability improvement of the bioleached sludge.
Activated sludge; Bioleaching; Dewaterability; Bio-substitution; Extracellular polymeric substances (EPS); Microbial community;
Separation and Purification Technology
Elsevierjournal
10.1016/j.seppur.2016.03.037
2016
53-59
Elsevier B.V.
