Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge

TY - JOUR

T1 - Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge

AU - Cai, Meiqiang

AU - Qian, Zhuohui

AU - Xiong, Xingaoyuan

AU - Dong, Chunying

AU - Song, Zhijun

AU - Shi, Yuejing

AU - Wei, Zongsu

AU - Jin, Micong

N1 - Publisher Copyright: © 2021 Elsevier B.V.

PY - 2022/4

Y1 - 2022/4

N2 - Pressurized vertical electro-osmotic dewatering (PVEOD) has been regarded as a feasible method to achieve sludge deep-dewatering, but the dewatering efficiency is still challenged by high electric resistance. This study employed cationic polyacrylamide (CPAM) as a skeleton builder to enhance electro-osmotic flow in PVEOD. The sludge dewatering efficiency and synergistic effect of CPAM and PVEOD were elucidated. The sludge morphology, surface property, extracellular polymeric substances (EPS) destruction and migration, spatial distributions of proteins and polysaccharides, and current changes were investigated. After the addition of optimal CPAM dose, the sludge formed a uniform and porous structure that provided water channels and enhanced electric transport, thus promoting EPS destruction. The sludge moisture content (MC) analysis indicated the more liberation of bound water due to EPS destruction. Besides, the re-flocculation of disintegrated sludge flocs improved the sludge filtration and thus dewaterability. Instantaneous energy consumption (Et,0.5) was optimized and two-step synergistic mechanism was thus proposed. These findings indicated that the combination of CPAM and PVEOD is a promising strategy to broaden the scope of industrial application of sludge deep-dewatering.

AB - Pressurized vertical electro-osmotic dewatering (PVEOD) has been regarded as a feasible method to achieve sludge deep-dewatering, but the dewatering efficiency is still challenged by high electric resistance. This study employed cationic polyacrylamide (CPAM) as a skeleton builder to enhance electro-osmotic flow in PVEOD. The sludge dewatering efficiency and synergistic effect of CPAM and PVEOD were elucidated. The sludge morphology, surface property, extracellular polymeric substances (EPS) destruction and migration, spatial distributions of proteins and polysaccharides, and current changes were investigated. After the addition of optimal CPAM dose, the sludge formed a uniform and porous structure that provided water channels and enhanced electric transport, thus promoting EPS destruction. The sludge moisture content (MC) analysis indicated the more liberation of bound water due to EPS destruction. Besides, the re-flocculation of disintegrated sludge flocs improved the sludge filtration and thus dewaterability. Instantaneous energy consumption (Et,0.5) was optimized and two-step synergistic mechanism was thus proposed. These findings indicated that the combination of CPAM and PVEOD is a promising strategy to broaden the scope of industrial application of sludge deep-dewatering.

KW - CPAM

KW - Electro-dewatering

KW - Electro-osmotic

KW - Extracellular polymeric substance

KW - Synergetic effect

UR - http://www.scopus.com/inward/record.url?scp=85120638417&partnerID=8YFLogxK

U2 - 10.1016/j.scitotenv.2021.151787

DO - 10.1016/j.scitotenv.2021.151787

M3 - Journal article

C2 - 34808190

AN - SCOPUS:85120638417

SN - 0048-9697

VL - 818

JO - Science of the Total Environment

JF - Science of the Total Environment

M1 - 151787

ER -