Mo^(6+)对活性污泥系统反硝化性能的影响

Effects of molybdenum(Ⅵ) on denitrification performance of the activated sludge process

采用对比实验的方法,在不同初始硝酸盐氮和COD质量浓度的条件下,对人工模拟的活性污泥系统投加不同质量浓度的Mo6+,以此考察Mo6+对活性污泥系统反硝化性能的影响。结果发现,Mo6+的质量浓度小于5mg?L-1以下时能够促进硝酸盐氮的去除,质量浓度为1mg?L-1时促进效果最好。Mo6+的质量浓度在4mg?L-1以下时,可以使COD去除效率增加,质量浓度为2mg?L-1时有最佳促进作用。Mo6+的质量浓度小于1g?L-1时可提高反硝化活性污泥的TTC-脱氢酶活性,过高质量浓度则表现出抑制作用。综合Mo6+的对硝酸盐氮和COD去除的影响规律以及对活性污泥TTC-脱氢酶活性的影响,认为Mo6+在质量浓度为1mg?L-1时对反硝化的促进作用最强。

Effects of molybdenum（Ⅵ） on denitrification performance of activated sludge process were investigated by a lab-scale once-though activated sludge unit treating synthetic wastewater with different influent strengths [20-60 mg · L^-1 nitrate with 150-500 mg ·L^-1 chemical oxygen command （COD）] and containing 0-5 mg ·L^-1 Mo （Ⅵ）. Nitrate and COD varieties during the reaction were studied with 2,3,5-triphenyl tetrazoliumchloride dehydrogenase activity （TTC-DHA） of activated sludge analyses. All results showed that, molybdenum could accelerate nitrate removal within 5 mg ·L^-1 concentration with the best stimulation effect appear at 1 mg ·L^-1. Within 4 mg ·L^-1 concentration, molybdenum has beneficial effect on COD removal with the best stimulation effect appear at 2 mg·L^-1. Within 1 mg·L^-1, TTC-DHA of activated sludge is enhanced while higher concentration of molybdenum shows inhibition effect. Based on the integrated effect of molybdenum on nitrate and COD removal, 1 mg ·L^-1 concentration of molybdenum is put forward as the best quantity for denitrification of activated sludge.