Effect of salinity change on MBR and the construction of an activated sludge model

Abstract

Abstract Tungsten smelting wastewater has high salt content and low C/N ratio, making it challenging to treat microbially. In this paper, membrane bioreactor (MBR) increased the concentration of microorganisms and strengthened the processing capacity. During the acclimation period of 3%−5% salinity, the removal rates of COD and NH4+-N fluctuated with salinity changed. Still, the COD, NH4+-N, and TN removal at the end of acclimation was 92.3%, 78%, and 65.78%, respectively. The 16s rRNA sequencing showed that nitrosating bacteria and microorganisms adapted to extreme environments were dominant. Using the ASM1 model and experimental data, a mathematical model suitable for simulating MBR treatment of high-salt wastewater was established. The average deviation between the simulation results and the actual average was within 5%, exhibiting a good prediction.