Treatment of landfill leachates with high ammonia concentrations in two-stage sequential batch biofilm reactor

Some efficient biological treatments were investigated to remove ammonia from the aged landfill leachate typical with a high concentration of the ammonia-nitrogen. A two-stage sequential batch biofilm reactor(SBBR) system was introduced to treat the landfill leachate. This process developed a microorganism system. In the primary SBBR stage using the method of domestication could withstand a high concentration of the ammonia-nitrogen. Experimental results show that through the two-stage SBBR system, the ammonia-nitrogen in the effluent can be reduced to 10 mg/L, so the first class criterion specified in GB 8978-1996 is achieved. When the ammonia-nitrogen loading is 1.20 kg/(m(3).d) in the primary reactor, the ammonia-nitrogen concentration in the effluent is 550 mg/L, and the removal rate is 52.9%. When the ammonia-nitrogen loading is 0.20 kg/(m(3).d) for the secondary reactor, the ammonia-nitrogen concentration in the effluent is reduced to 10 mg/L, and the total removal rate is 98.1%. Compared with the single-stage SBBR system, the reaction volumes of the two-stage SBBR can be reduced by 66.7%.