Optimizing dose of coagulant and pH values for membrane fouling control in a submerged membrane bioreactor. Issue 10 (20th July 2022)

• Record Type: Journal Article
• Authors: Nazmkhah, Abbas; Oghyanous, Farid Alizad; Etemadi, Habib; Yegani, Reza
• Is Part Of: Journal of chemical technology & biotechnology. Volume 97:Issue 10(2022)
• Page Start: 2794
• Page End: 2804
• Publication Date: 2022-07-20
• Subjects: membrane bioreactor -- membrane fouling -- coagulation -- polyaluminum chloride coagulant -- pH optimization; Biotechnology -- Periodicals; Chemistry, Technical -- Periodicals; Chemical engineering -- Periodicals; Industries -- Environmental aspects -- Periodicals; 660
• DOI: 10.1002/jctb.7148
• Languages: English
• ISSNs: 0268-2575

Abstract

Abstract: BACKGROUND: This study assessed the impact of using polyaluminum chloride (PAC) and of changing pH values on the removal efficiency and membrane fouling in a submerged membrane bioreactor (MBR) system utilized to treat real pharmaceutical wastewater. RESULTS: The results revealed that sweep coagulation and a neutral pH were suitable for decreasing soluble microbial products (SMP) in the activated sludge, and the sludge filterability performed better with bridging coagulation and an acidic pH (6.5 < pH < 7). In addition, it was found that membrane fouling was greatly alleviated when PAC was added under the optimized conditions to the MBR (PAC concentration = 100 mg L −1 and pH = 7). Further analyses of membrane fouling mechanisms indicated that adding PAC to the MBR increased the biomass floc size and reduced the SMP concentration and the carbohydrate content in the mixed liquor. CONCLUSION: The detailed analyses of the membranes' cake layers showed that the presence of PAC decreased the amount of fluorescent organic carbons, proteins, and carbohydrates. These changes in sludge characteristics considerably contributed to the reduction of reversible and irreversible membrane fouling. © 2022 Society of Chemical Industry (SCI).