Synergistic effects of combining ozonation, ceramic membrane filtration and biologically active carbon filtration for wastewater reclamation

• Published in: Journal of hazardous materials Vol. 382; p. 121091
• Main Authors: Zhang, Kai, Zhang, Zheng-hua, Wang, Hao, Wang, Xiao-mao, Zhang, Xi-hui, Xie, Yuefeng F.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.01.2020
• Subjects: Biologically active carbon (BAC); Ceramic membrane; Membrane fouling; Ozonation; Wastewater reclamation; Ozonation; Ceramic membrane; Wastewater reclamation; Membrane fouling; Biologically active carbon (BAC)
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121091

[Display omitted] •A process including ozonation, CMF and BAC filtration was used for wastewater reclamation.•The process performed very well in removing both conventional and emerging contaminants.•The ceramic membrane materials could catalyze ozonation of organic substances.•In situozonation could effectively control fouling of the ceramic membranes.•Ceramic membrane filtration prolonged the filtration stage of the BAC filter. In this study, we proposed to apply an integrated process which is comprised of in situ ozonation, ceramic membrane filtration (CMF) and biologically active carbon (BAC) filtration to wastewater reclamation for indirect potable reuse purpose. A pilot-scale (20 m3/d) experiment had been run for ten months to validate the prospect of the process in terms of treatment performance and operational stability. Results showed that the in situ O3 + CMF + BAC process performed well in pollutant removal, with chemical oxygen demand, ammonia, nitrate nitrogen, total phosphorus and turbidity levels in the treated water being 5.1 ± 0.9, 0.05 ± 0.01, 10.5 ± 0.8, <0.06 mg/L, and <0.10 NTU, respectively. Most detected trace organic compounds were degraded by>96%. This study demonstrated that synergistic effects existed in the in situ O3 + CMF + BAC process. Compared to pre-ozonation, in situ ozonation in the membrane tank was more effective in controlling membrane fouling (maintaining operational stability) and in degrading organic pollutants, which could be attributed to the higher residual ozone concentration in the tank. Because of the removal of particulate matter by CMF, water head loss of the BAC filter increased slowly and prolonged the backwashing interval to 30 days. BAC filtration was also effective in removing ammonia and N-nitrosodimethylamine from the ozonated water.