厌氧氨氧化工艺的抑制现象

厌氧氨氧化(Anammox)工艺因其高效低耗优势,在废水生物脱氮领域中具有广阔的应用前景.然而,基质、有机物、盐度、重金属、磷酸盐及硫化物等物质对Anammox工艺产生的抑制作用制约了工艺的推广应用.基质主要通过游离氨和游离亚硝酸对Anammox产生抑制,而温度和pH是基质抑制的重要调控参数.非致毒性有机物对Anammox的作用因其种类跟浓度而异.在较低的浓度条件下对Anammox的抑制作用不显著,而高于抑制阈值将严重抑制Anammox.其抑制机制尚无定论.部分研究证明致毒性有机物(醇、醛、酚及抗生素等)对Anammox具有抑制作用,但研究有待拓展深化.超过抑制阈值的盐度会抑制Anammox活性,但合适的盐度(3~15 g L-1NaCl)却能够促进Anammox生物颗粒的形成.重金属对Anammox的抑制报道较少.因试验条件及菌种等的差异使得磷酸盐及硫化物对Anammox的抑制在不同试验中存在很大差异.Anammox抑制是可控的,通过pH和温度调节、基质浓度及负荷控制、污泥驯化以及添加辅助剂等方法可解除或缓解抑制.建议今后在特种废水的Anammox脱氮、复合抑制以及Anammox抑制的分子生态学机理等方面开展深入研究.

Inhibition Phenomenon of Anammox Process

Anammox process is a promising method for biological nitrogen removal from wastewater with a high efficiency and low consumption.However,the applications of this method are restricted by some factors,such as substrate,organic matter,salinity,heavy metal,phosphate and sulfide.The substrate inhibition is mainly caused by free ammonia or free nitrous acid,which is dependent on ammonia or nitrite level,pH and temperature.The effects of non toxic organic on Anammox are dependent on the species and level of organic.Generally,the influence of non toxic organic on Anammox at a lower level is not significant;however,serious inhibition would be observed at a level exceeding the inhibitory threshold,and the mechanism need further study.Some studies demonstrate that the toxic organic matter(e.g.alcohols,aldehydes,phenolic and antibiotics) inhibit Anammox processes,but further researches are required.A certain concentration of salt(3~15 g L-1 NaCl) can promote the formation of Anammox granular sludge,but the salinity exceeding the threshold will inhibit Anammox activity.However,there are few reports on the inhibition of heavy metal on Anammox.The inhibition effects of phosphate and sulfide on Anammox vary in different studies.The inhibition of Anammox can be regulated by pH and temperature adjusting,substrate concentration and loading rate control,sludge acclimatization and auxiliary addition.Further researches are suggested in the Anammox treatment of special wastewater,composite inhibition as well as mechanism of molecular ecology.