Deng Jing, Wang Hui, Gao Ruhao, Ma Xin, Chen Minjie, Xu Dong, Cai Anhong
College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou 310023, China.
College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
J Environ Manage. 2025 Jan;373:123552. doi: 10.1016/j.jenvman.2024.123552. Epub 2024 Dec 3.
Dewatering of waste activated sludge is a necessary step for achieving subsequent reduction, stabilization, and resource utilization. In this study, Fe/periodate (PI) coupled with polyoxometalates (POMs) conditioning was tested for realizing sludge deep dewatering. After the addition of POMs (0.20 mmol g VSS), Fe/PI/POMs conditioning enhanced the efficiency of sludge dewatering by 42.93% compared to Fe/PI conditioning. It was found that the electrostatic repulsion posed a significant influence on the interaction between POMs and proteins. The reduction of electrostatic repulsion facilitated the proximity of POMs to the sludge flocs and promoted its reaction. The strong acidity and interaction with cells of POMs could induce the damage or apoptosis in sludge cells, resulting in the release of intracellular substances. The active radicals generated by Fe/PI process attacked TB-EPS, causing the dissolution of EPS and the decomposition of hydrophilic substances. With the assistance of Fe/PI process, POMs exhibited an enhanced cell-disruptive effect, thereby inducing the liberation of a greater quantity of intracellular substances. Moreover, Fe/PI/POMs conditioning effectively lowered the zeta potential of sludge system, facilitating the interaction between negatively charged POMs anions and the positively charged regions of proteins. This interaction tended to favor adsorption and precipitation rather than destruction. The adsorption and sedimentation of proteins by POMs further reduced the hydrophilicity of sludge system, thereby enhancing sludge dewaterability. Furthermore, POMs could enhance the electron transfer capacity of sludge system, which was beneficial for subsequent filtrate denitrification treatment.
废活性污泥的脱水是实现后续减量、稳定化及资源利用的必要步骤。本研究测试了铁/过碘酸盐（PI）与多金属氧酸盐（POMs）联合调理以实现污泥深度脱水。添加POMs（0.20 mmol g VSS）后，与铁/PI调理相比，铁/PI/POMs调理使污泥脱水效率提高了42.93%。研究发现，静电排斥对POMs与蛋白质之间的相互作用有显著影响。静电排斥的降低促进了POMs与污泥絮体的接近并促进其反应。POMs的强酸性及其与细胞的相互作用可诱导污泥细胞损伤或凋亡，导致细胞内物质释放。铁/PI过程产生的活性自由基攻击TB-EPS，导致EPS溶解和亲水物质分解。在铁/PI过程的辅助下，POMs表现出增强的细胞破坏作用，从而诱导释放更多的细胞内物质。此外，铁/PI/POMs调理有效降低了污泥体系的ζ电位，促进了带负电荷的POMs阴离子与蛋白质带正电区域之间的相互作用。这种相互作用倾向于有利于吸附和沉淀而非破坏。POMs对蛋白质的吸附和沉降进一步降低了污泥体系的亲水性，从而提高了污泥脱水性能。此外，POMs可增强污泥体系的电子转移能力，这有利于后续滤液的反硝化处理。
