预氯化去除饮用水水源中高浓度氨氮等污染因子的应急处理研究

COUNTER-EMERGENCY REMOVING POLLUTANTS AT HIGH CONCENTRATION OF WATER SOURCE OF DRINKING WATER BY PRE-CHLORINATION TECHNOLOGY

从水污染应急的角度,进行了氨氮的应急处理研究。氨氮去除采用常规工艺与预氯化为主要预氧化工艺比较试验。结果表明,常规的混凝、沉淀工艺对氨氮的去除作用有限,其主要作用仅为去除水中的致浊物质及部分有机物。在投加次氯酸钠作为预氧化药剂之后,发现其具有较好的去除氨氮的效果,当原水氨氮的质量浓度在1.0mg·L-1左右时,次氯酸钠投加量为8.4mg·L-1,能够高效地去除氨氮,沉后水氨氮质量浓度为0.292mg·L-1(达到国家一级水源水质标准),去除率为68.78%,UV254也有32.26%的去除率;如同时需要更高的UV254的去除率,则可选用次氯酸钠9.6mg·L-1的投加量,此时氨氮的去除率为87.20%,水源水的氨氮质量浓度在0.123mg·L-1的水平,同时UV254的去除率可以达到45.16%,从而控制THMs和THMFP这些毒副产物形成量在相当低的水平,是最理想的选择。此法在短时间内作为去除氨氮这种毒性很强的物质的应急使用是可行的,但不能长期使用,因为对微污染水源而言,如投氯量把握不当,则也会产生较多的毒副产物,对饮用水的质量安全构成明显影响。

Counter-emergency treatment was carried out, which took ammonia-nitrogen as the main pollutant Comparative study on the conventional water treatment technology with the pre-chlorination technology as the ammonia-nitrogen removal method was done. The results showed that the conventional wa- ter treatment technology had little effect on removing ammonia-nitrogen, and its main function was to remove the turbidity material and the partial organic matters from the destination water. After adding the sodium hypochlorite, it had a good effect in removing ammonia-nitrogen. As the ammonia-nitrogen cone entration of water is 1.0 mg·L^-1, adding sodium hypochl orite at a dosage of 8.4 mg·L^-1, could get an effective elimination ofammonia-n itrogen; after sedimentation, the ammonia-nitrogen concentration of water went down to 0.292mg·L^-1 （achieve 1 grade standard of water source of drinking water of national standard）, and the removal rate was 68.78%,the removal rate of UV254 was 32.26%; if it should be necessary for a more removal rate of UV254 in same time, chose thedosage of sodium hypochlorite is9.6mg·L^-1,the removal rate of ammonia-nitrogen is87.20%,the ammonia-nitrogen concentration of water will go down to0.123mg·L^-1, and the removal rate of UV254 is 45.16%, so that can control formed amount of THMs and THMFP in a smallest level,the treatment concentration is best for choose. This measure is good and viable for counter-emergency treatment ,but it is not suit to long-term use,especially not propriety ofthe chlorination dosage could lead to the problem of water quality.