Pretreatment for alleviation of RO membrane fouling in dyeing wastewater reclamation
Adsorption and coagulation were commonly used to alleviate reverse osmosis (RO) membrane fouling caused by dissolved organic matters (DOM), but the effects of changed composition and structure of DOM in dyeing wastewater after adsorption and coagulation on RO membrane fouling have seldom been studie...
Saved in:
Published in | Chemosphere (Oxford) Vol. 292; p. 133471 |
---|---|
Main Authors | , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Ltd
01.04.2022
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Adsorption and coagulation were commonly used to alleviate reverse osmosis (RO) membrane fouling caused by dissolved organic matters (DOM), but the effects of changed composition and structure of DOM in dyeing wastewater after adsorption and coagulation on RO membrane fouling have seldom been studied. This study aimed at resolving the mechanism how the RO membrane fouling during dyeing wastewater treatment was alleviated by using adsorption and coagulation. The dyeing wastewater caused serious RO membrane fouling. Pretreatment with granular activated carbon (GAC), polyferric sulfate (PFS) and polyaluminum chloride (PACl) were conducted. It was shown that GAC could remove most of the DOM (95%) and preferred to adsorb protein, hydrophobic neutrals and fluorescent compounds. Both coagulants of PFS and PACl preferred to remove polysaccharides (the removal rate was 9–19% higher than that of DOM), high-MW compounds and these compounds with high fouling potential. Afterwards, the RO membrane fouling potential of the dyeing wastewater was tested. The GAC and PFS performed well to alleviate fouling. After GAC treatment, the decline rate of RO flux was similar to that of raw wastewater after 6-fold dilution. With pretreatment by PFS or PACl, the fouling potential of dyeing wastewater was much lower than that of raw wastewater after diluted to the same DOM content. Changes in polysaccharides content in the DOM had more effects on RO membrane fouling than that of proteins after these pretreatment. Although the DOM changed significantly after pretreatment, the fouling type was still intermediate blocking.
[Display omitted]
•Activated carbon preferred to remove fluorescent compounds and low-MW DOM.•Coagulants of PFS and PACl preferred to remove polysaccharides and high-MW DOM.•PFS and PAC preferred to remove compounds with high fouling potential.•PFS and GAC effectively alleviated RO membrane fouling caused by dyeing wastewater.•Polysaccharides had more negative effects on RO membrane fouling than proteins. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0045-6535 1879-1298 |
DOI: | 10.1016/j.chemosphere.2021.133471 |