Domestic wastewater treatment and membrane fouling control by an innovative MBR system combined with adsorption and rough-sedimentation

Membrane fouling is one of the main factors limiting the widespread application of membrane bioreactor (MBR). Aiming at the instable nitrification and membrane fouling of traditional MBR, an innovative MBR system combined with an adsorption and a rough sedimentation chamber was extensively investigated for domestic wastewater treatment and membrane fouling control. Experimental results revealed that pollutants removal was improved and the membrane fouling was also effectively reduced with the separation of organics and nitrogen. Approximately 89.7% of the organics in influent was removed in the adsorption and rough sedimentation, thus improved the nitrification in MBR. Effluent COD and NH₄⁺-N were averaged at 24 mg/L, 0.78 mg/L, respectively, corresponding to the removal of 95.9% and 98.1%. On the other hand, the concentrations of MLSS, EPS, and SMP were obviously reduced due to the decrease of carbon to nitrogen ratio and the increase of nitrifying bacteria, resulting to the average values of 5 185 mg/L, 41 mg/g MLSS and 2.62 mg/g MLSS. As a constant flux about 4 L/(m²·h) applied, the TMP was kept around 20 kPa. To sum up, the separation of carbon and nitrogen helped improve pollutants removal and control the membrane fouling.