化学沉淀—折点氯化法处理稀土氨氮废水

采用化学沉淀—折点氯化法去除稀土氨氮废水中的氨氮。化学沉淀试验表明,调节废水pH=7,沉淀时间15min,废水中氨氮的去除率可达90.64%;折点氯化试验表明,调节废水pH=7,次氯酸钠溶液加入量为理论量的1.4倍,反应时间15min,废水中氨氮浓度可降至8.35mg/L,处理后的废水满足稀土工业废水氨氮排放标准,并且本工艺是经济可行的。

Treatment of Ammonia-nitrogen-bearing Wastewater by Chemical Precipitation and Break Point Chlorination

Ammonia-nitrogen-bearing wastewater from rare earth industry was treated by chemical precipitation and break point chlorination. Chemical precipitation tests results indicate that removal rate of NH4 -N is 90.64% under the conditions of pH=7 and precipitation time of 15 minutes. Break point chlorination tests results indicate that NH4 -N in rare earth wastewater can be reduced to 8.35 mg/L under the conditions of pH=7, 1.4 times of theoretical dosage of sodium hypochlorite solution and reaction time of 15 minutes. The treated wastewater meets the standard of RE industrial wastewater ammonia emissions, and the treating processes are economically feasible.