Study On Salt Accumulation And Membrane Fouling In AnOMBR Process

The anaerobic forward osmosis membrane bioreactor?AnOMBR?technology not only has the high retention performance of forward osmosis?FO?,but also has the advantages of low energy consumption and resource recovery of anaerobic biotechnology.The advantage of energy consumption and resource recovery is a new technology with great development prospects.Based on the investigation of short-term pollution and salt accumulation performance of CTA-FO membrane in AnOMBR system,the experiment further explored the reactor salt accumulation characteristics of CTA membrane and TFC membrane material under long-term pollution and the formation process of the FO membrane's pollution layer.The experimental results show that the processing performance of the CTA film is:TOC removal rate reaches 97%,TP removal rate can reach 100%,TN removal rate is67%,NH₄⁺-N removal rate is 66%;TFC film processing performance is: TOC The removal rate reached 98%,TP removal rate reached 100%,TN removal rate was 62%,and NH₄⁺-N removal rate was 62%.The removal rate of N by CTA film is slightly higher than that of TFC film.Affected by salt accumulation with the increase of membrane pollution time,the sludge particle size will gradually decrease,and the sludge concentration will continue to decrease.The sludge particle size of the CTA membrane changed from the initial413 nm to 66.91 nm at the end,the sludge concentration decreased from 4.2mg/L to3.58mg/L,and the sludge particle size of the TFC membrane changed from the initial405.7nm to the end 69.96 nm,the sludge concentration decreased from 4.12 mg / L to3.26mg/L.Membrane pollution is divided into inorganic pollution and organic pollution.Inorganic pollution is mainly caused by Ca²⁺ and Mg²⁺.After 24 days of contamination,the concentration of Ca²⁺ on the CTA film was 37.65 mg/L,and the concentration of Mg²⁺ was 0.719 mg/L.The concentration of Ca²⁺ on the TFC film was41.25 mg/L,and the concentration of Mg²⁺ was 1.885mg/L.Compared with CTA membrane,TFC inorganic pollution is more serious.The organic pollution components are mainly proteins and polysaccharides,and ?-polysaccharides are more likely to deposit on the membrane surface than ?-polysaccharides.The formation process of organic pollutants on the FO film is not related to the material of the film used in the experiment and CTA membrane and TFC membrane surface pollutants are formed in a similar way.It was found that the organic pollutants on the surface of the TFC film are more dense,and the organic pollution of the TFC film is more serious than that of the CTA film.For membrane fouling experiments,CTA membranes are recommended.