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Membrane Water Treatment Volume 8, Number 2, March 2017 , pages 185-199 DOI: https://doi.org/10.12989/mwt.2017.8.2.185 |
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Effect of coagulation conditions on ultrafiltration for wastewater effluent |
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Sung Kyu Maeng, Thomas C. Timmes and Hyun-Chul Kim
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| Abstract | ||
| Low-pressure membrane filtration is increasingly used for tertiary treatment of wastewater effluent organic matter (EfOM), mainly comprising organic base/neutral compounds. In-line coagulation with underdosing, charge neutralization, and sweep floc conditions prior to ultrafiltration (UF) was studied to determine removals of the EfOM components and consequent reduction of fouling using polyethersulfone membranes. Coagulation and UF substantially reduced fouling for all coagulation conditions while removing from 7 to 38% of EfOM organic acids. From 7 to 16% of EfOM organic base/neutrals were removed at neutral pH but there was no significant removal for slightly acid coagulation conditions even though fouling was substantially reduced. Sweep floc produced the lowest resistance to filtration but may be inappropriate for in-line use due to the large added volume of solids. Charge-neutralization resulted in poor recovery of the initial flux with hydraulic cleaning. Under-dosing paralleled sweep floc in reducing hydraulic resistance to filtration (for sub-critical flux) and the initial flux was also easily recovered with hydraulic cleaning. Hydrophobic and hydrophilic base/neutrals were identified on the fouled membranes but as previously reported the extent of fouling was not correlated with accumulation of organic base/neutrals. | ||
| Key Words | ||
| effluent organic matter; in-line coagulation; ultrafiltration; fouling; membrane autopsy | ||
| Address | ||
| Sung Kyu Maeng : Department of Civil & Environmental Engineering, Sejong University, Seoul 143-747, Republic of Korea Thomas C. Timmes : US Army Center for Environmental Health Research, Fort Detrick, MD 21702, USA Hyun-Chul Kim : Water Resources Research Institute, Sejong University, Seoul 143-747, Republic of Korea | ||
