College of Chemistry and Environmental Engineering, Jiujiang University, Jiujiang 332005, China and Jiujiang Key Laboratory of basin management and ecological protection, Jiujiang University, Jiujiang Jiangxi, 332005, China E-mail:
College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou Gansu, 730050, China.
Water Sci Technol. 2020 Jun;81(12):2585-2598. doi: 10.2166/wst.2020.319.
Bioleaching, a technologically and economically feasible technology, is considered as the high efficiency method to improve dewaterability in sewage sludge. The objective of this study was to investigate the effect of different sludge concentrations on bioleaching dewaterability and understand the mechanism of the effect of bioleaching on sludge dewaterability. Variation in pH, oxidation-reduction potential (ORP), capillary suction time (CST), specific resistance to filtration (SRF) and different fractions of extracellular polymeric substances (EPS) including slime EPS (S-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (TB-EPS) were determined. Different sludge concentrations (5, 10, 15, 20 and 30 g·L) were selected to investigate during bioleaching. Results indicated that sludge buffering capacity significantly inhibited bioleaching efficiency as sludge concentrations increased. Optimum enhancements in sludge dewaterability were observed during the 10 g·L sludge concentration treatment, and reached a maximum when the pH was 2.11. The variation of different fractions of EPS revealed that the ratio of S-EPS/TB-EPS significantly affected sludge dewaterability. Principal component analysis and Pearson's correlation analysis both provided evidence that the higher TB-EPS followed by a very large reduction was positively correlated with sludge dewaterability. However, the increase of protein and DNA in S-EPS content was negatively correlated with sludge dewaterability.
生物沥滤是一种技术和经济上可行的技术，被认为是提高污水污泥脱水性能的高效方法。本研究的目的是研究不同污泥浓度对生物沥滤脱水性能的影响，并了解生物沥滤对污泥脱水性能的影响机制。测定了 pH 值、氧化还原电位 (ORP)、毛细吸留时间 (CST)、比过滤阻力 (SRF) 和不同胞外聚合物物质 (EPS) 分数的变化，包括粘性 EPS (S-EPS)、松散结合 EPS (LB-EPS) 和紧密结合 EPS (TB-EPS)。选择不同的污泥浓度（5、10、15、20 和 30 g·L）进行生物沥滤。结果表明，随着污泥浓度的增加，污泥缓冲能力显著抑制了生物沥滤效率。在 10 g·L 污泥浓度处理时，污泥脱水性能得到了最佳的提高，当 pH 值为 2.11 时达到最大值。不同 EPS 分数的变化表明，S-EPS/TB-EPS 的比值对污泥脱水性能有显著影响。主成分分析和 Pearson 相关分析都提供了证据，表明较高的 TB-EPS 随后是非常大的减少与污泥脱水性能呈正相关。然而，S-EPS 中蛋白质和 DNA 含量的增加与污泥脱水性能呈负相关。
