Study on the Treatment of Tannery Wastewater with the High Concentration of Ammonia Nitrogen by MBR

The removal efficiency of CODCr and ammonia nitrogen of the high concentration of ammonia nitrogen from tannery effluent by membrane bioreactor (MBR) was investigated. The results showed that when the operation of MBR is stable, influent CODCr loads are less than 4.8 kg/m(3).d, the average removal rate of CODCr was over 88%, the removal rate of ammonia nitrogen reached to 90%; when dissolved oxygen (DO) was 1.2 mg/L and 1.8 mg/L, the reactor still has excellent treatment efficiency, and the removal rate of CODCr and ammonia nitrogen can achieved over 90%. In addition, through the study of membrane flux, it is easy to find that membrane flux decreases rapidly, the membrane requires periodic cleansing.