Abstract:Conventional biological nitrogen removal process achieves low nitrogen removal efficiency. In this paper, the two-stage OA biochemical waste water processing technique was applied by Ganzhou Rare Earth Mining Co., Ltd., to deal with ammonia nitrogen pollution in the water environment of ion-type rare earth mine. The influent ammonia nitrogen was 100~150 mg/L, and the total nitrogen content was 150~200 mg/L. After AO biochemical treatment, the concentration of ammonia nitrogen in the effluent was below 10 mg/L, and the total nitrogen content was below 30 mg/L, which fully meet the national emission standards for waste water discharge (GB26451—2011). Under these conditions, the removal efficiency of ammonia nitrogen was over 94.1% and that of total nitrogen was 85.9%, which greatly improved the denitrification efficiency, thus meeting the discharge standard of ammonia nitrogen. The engineering practice results suggested that this method has the advantages of good and stable treatment effect, as well as the social and environmental profit.