State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environmental and municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, Shaanxi, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Sci Total Environ. 2021 Dec 20;801:149753. doi: 10.1016/j.scitotenv.2021.149753. Epub 2021 Aug 19.
Electro-dewatering (ED) is an attractive technology for enhancing dewaterability of waste activated sludge (WAS), and the distribution and composition of EPS and secondary structure of extracellular protein in sludge has a great influence on the sludge dewaterability. Therefore, in order to optimize and regulate sludge ED process, it is necessary to study the influence of EPS components and composition on the efficiency of sludge ED. In this study, the effects of distribution and composition of EPS and the structure of extracellular proteins on the ED rates and performance were analyzed using eight sludges from different sewage treatment process. The results showed that ED rates at both electrodes were significantly negatively correlated with the concentration of soluble EPS (S-EPS) and loosely bound EPS (LB-EPS), and this correlation was gradually weakened with the in-depth structure of layered EPS structure. High concentration of S-EPS and LB-EPS decreased the initial current and the pH gradient, deteriorating the anodic oxidation and acidification, which affect the release and degradation of EPS. Additionally, the proteins secondary structure can be destroyed and transformed by anodic oxidation and acidification, which can impact the protein water-holding capacity and ED performance.
电脱水（ED）是一种很有吸引力的技术，可以提高废水活性污泥（WAS）的脱水能力，而 EPS 的分布和组成以及细胞外蛋白质的二级结构对污泥的脱水性能有很大的影响。因此，为了优化和调节污泥 ED 工艺，有必要研究 EPS 成分和组成对污泥 ED 效率的影响。本研究采用来自不同污水处理工艺的 8 种污泥，分析了 EPS 的分布和组成以及细胞外蛋白质的结构对 ED 速率和性能的影响。结果表明，两极的 ED 速率与可溶性 EPS（S-EPS）和松散结合 EPS（LB-EPS）的浓度呈显著负相关，并且这种相关性随着分层 EPS 结构的深入而逐渐减弱。高浓度的 S-EPS 和 LB-EPS 降低了初始电流和 pH 梯度，恶化了阳极氧化和酸化，从而影响 EPS 的释放和降解。此外，阳极氧化和酸化会破坏和转化蛋白质的二级结构，从而影响蛋白质的持水能力和 ED 性能。
