Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4996721 | Bioresource Technology | 2017 | 32 Pages |
Abstract
In this study, a chemically enhanced backflush (CEB) cleaning method using NaOH solution was proposed for fouling mitigation in anaerobic membrane bioreactors (AnMBRs). Ex-situ cleaning tests revealed that NaOH dosages ranging from 0.05 to 1.30Â mmol/L had positive impacts on anaerobic biomass, while higher dosages (>1.30Â mmol/L) showed inhibition and/or toxic impacts. In-situ cleaning tests showed that anaerobic biomass could tolerate much higher NaOH concentrations due to the alkali consumption by anaerobic process and/or the buffering role of mixed liquor. More importantly, 10-20Â mmol-NaOH/L could significantly reduce membrane fouling rates (4-5.5 times over the AnMBR with deionized water backflush) and slightly improve methanogenic activities. COD removal efficiencies were over 87% and peaked at 20Â mmol-NaOH/L. However, extremely high NaOH concentration had adverse effects on filtration and treatment performance. Economic analysis indicated that 12Â mmol/L of NaOH was the cost-efficient and optimal fouling-control dosage for the CEB cleaning.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
Xiaojie Mei, Pei Jun Quek, Zhiwei Wang, How Yong Ng,