高锰酸盐复合药剂预氧化对摇蚊幼虫DBPsFP的去除控制研究

以花翅摇蚊幼虫为试验对象,研究高锰酸盐复合药剂预氧化对摇蚊幼虫代谢产物在氯化消毒过程中消毒副产物前体物的去除控制.研究表明:在p H由5升高到9时,三氯乙酸(TCAA)与二氯乙酸(DCAA)的浓度呈逐渐减少趋势;p H由5升高到7时,三氯甲烷(TCM)和三氯乙腈(TCAN)的浓度减幅最大,1,1-二氯丙酮(1,1-DCP)和1,1,1-三氯丙酮(1,1,1-TCP)则在p H为8时浓度达到最低值;随着药剂投加量的增加,TCM呈现出持续稳定增长趋势,DCAA呈总体下降趋势,而TCAN、1,1-DCP、1,1,1-TCP和TCAA则先增加后减少,高锰酸盐的投加量为3mg·L-1时,消毒副产物去除效果显著;延长预反应时间,TCM呈总体上升趋势,1,1-DCP、DCAA、TCAA呈下降趋势,TCAN、1,1,1-TCP呈先增加后减少的趋势,综合考虑最佳预氧化时间为30 min;投加混凝剂能够有效控制消毒副产物前体物的生成,随着混凝剂的不断增加,TCM、1,1,1-TCP呈先增加后减少的趋势,TCAN、1,1-DCP、DCAA、TCAA浓度则逐渐降低,在投量为40 mg·L-1时,达到最低值.

Control of DBPsFP removal produced by chironomid larvae metabolization through potassium permanganate composite chemicals pre-oxidation method

The objective of present study is to investigate the removal of Chironomus kiiensis metabolite by permanganate composite chemicals (PPC) pre-oxidation process. Chironomus kiiensis metabolite is also called disinfection by-products precursors which produce disinfection by-products during chlorination process. The results show that the concentration of trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) decrease gradually with pH increasing from 5 to 9. Concentration of trichloromethane (TCM) and trichloroacetonitrile (TCAN) decrease obviously with pH increasing from 5 to 7. When pH is 8, 1,1-dichloropropanone (1,1-DCP) and 1,1,1-trichloropropanone (1,1,1-TCP) reach the lowest concentration. In response to increasing dosage of permanganate composite chemicals, TCM concentration shows a steady growth trend, DCAA decreases in general, while TCAN, 1,1-DCP, 1,1,1-TCP and TCAA increases firstly and then decreases. When the dosage of PPC is controlled at 3 mg·L^-1, the disinfection by-products reach their best removal efficiency. With the prolonged pre-oxidation time, TCM concentration increases, 1,1-DCP, DCAA and TCAA decrease, while 1,1,1-TCP and TCAN increases firstly and then decreases. Overall, the best pre-oxidation time should be 30 min. Adding coagulant could effectively control the generation of DBPsFP. By continuously increasing the dosage of coagulant, TCM and 1,1,1-TCP concentration increase firstly and then decrease while TCAN, 1,1-DCP, DCAA and TCAA decrease continuously. When the amount of coagulant is controlled at 40 mg·L^-1, the disinfection by-products reach the lowest value.