School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China.
School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China.
Sci Total Environ. 2023 Jan 10;855:158648. doi: 10.1016/j.scitotenv.2022.158648. Epub 2022 Sep 9.
Reducing the water content of waste activated sludge (WAS) is critical for sludge treatment and disposal in wastewater treatment plants (WWTPs). In this study, a new combined conditioning processes by using lysozyme (LZM) and free nitrous acid (FNA) were proposed and demonstrated to enhance the dewaterability of WAS. The water content of sludge cake dropped from 82.82 % to 68.42 % (1 h FNA treatment + 1 h LZM treatment) and 69.52 % (6 h FNA treatment + 1 h LZM treatment) with the combined FNA and LZM treatment; and the corresponding capillary suction time (CST) reduction efficiency increased 49.29 % (1 h FNA treatment + 1 h LZM treatment) and 52.98 % (6 h FNA treatment + 1 h LZM treatment). A comprehensive investigation conducted in this study revealed the underlying mechanism of dewaterability improvement lies in the transformations of extracellular polymeric substances (EPS). The combined conditioning led to enhanced hydrophobicity in the sludge, as suggested by FTIR protein secondary structure and interfacial free energy. The reduced zeta potential and the potential barrier indicated the reduction of the repulsive force of sludge particles and the bound water content in the conditioned floc. The hydrophobicity, flow permeability and flocculability were enhanced after combined treatment, leading to the release of bound water.
降低废水活性污泥（WAS）的含水量对于污水处理厂（WWTP）的污泥处理和处置至关重要。在本研究中，提出并证明了一种新的组合调理工艺，即使用溶菌酶（LZM）和游离亚硝酸（FNA）来增强 WAS 的脱水性能。与单独的 FNA 或 LZM 处理相比，组合 FNA 和 LZM 处理 1 h 可使污泥饼的含水量从 82.82%降低至 68.42%（1 h FNA 处理+1 h LZM 处理）和 69.52%（6 h FNA 处理+1 h LZM 处理），相应的毛细吸水时间（CST）减少效率提高了 49.29%（1 h FNA 处理+1 h LZM 处理）和 52.98%（6 h FNA 处理+1 h LZM 处理）。本研究进行了全面的调查，揭示了脱水性能提高的潜在机制在于细胞外聚合物（EPS）的转化。组合调理导致污泥疏水性增强，这可以通过傅里叶变换红外光谱（FTIR）蛋白质二级结构和界面自由能得到证明。减少的zeta 电位和势垒表明污泥颗粒的排斥力和结合水含量降低，调理絮体中的结合水得到释放。组合处理后，疏水性、流动渗透性和絮凝性增强，导致结合水的释放。
