生物脱氮系统中无厌氧释磷的生物除磷工艺

采用2个工作容积为6L的SBR反应器(1#和2#)分别进行人工废水的脱氮试验研究,其中1#进水是以醋酸钠为碳源,2#以淀粉为碳源,2个反应器进水的COD、氨氮、磷酸盐和硝氮浓度一致.2个反应器均按缺氧76min-好氧294min交替的模式运行·在COD/NO-3N比为8.76:1(400 mg·L-1:45.67 mg·L-1)和15.03:1(400 mg·L-1:26.61 mg·L-1)2种水质条件下.考察了2个反应器对COD、氮和磷的脱除情况.结果表明.2种碳氮比下,1#反应器为传统的硝化.反硝化生物脱氮.对硝酸盐和COD具有较好的脱除效果,对磷基本不能去除;2#反应器在缺氧段发生反硝化脱氮作用,在好氧时段发生硝化作用,同时伴有明显的磷去除.这种现象稳定持续,致使反应器中污泥浓度明显增加.结合pH、DO等环境因素的分析,判定这是一种新型的非传统生物除磷现象.

Phosphorus removal without anaerobic release in a biological nitrogen removal system

In order to investigate the influence of denitrification of synthetic wastewater on sludge bulking,two Sequencing Batch Reactors(SBR)(named Reactors 1^# and 2^#)with working volume of 6 Lwere adopted in the study.Reactor 1^# was fed with wastewater containing sodium acetate as carbon source and Reactor 2^# was fed soluble starch.Both influents had the same concentration of COD,nitrate-nitrogen,orthophosphate and ammonium-nitrogen.The reactors were both run in alternating anoxic and aerobic conditions that lasted 76 min and 294 min,respectively.Two kinds of synthetic wastewater with CODto NO₃^--N ratios of 8.76:1(i.e.400 mg·L^-1to 45.67 mg·L^-1)and 15.03:1(i.e.400 mg·L^-1 to 26.61 mg·L^-1)were fed to the two reactors.The removal of nitrogen,phosphorus,COD,DO,pH,MLSS and MLVSS were monitored.The results showed that good performance of denitrification and nitrification were established in Reactor 1^# without any enhanced biological phosphorus removal(EBPR),but with nitrogen removal.Obvious phosphorus removal was observed in the aerobic phase in Reactor 2^#,and it lasted steadily for weeks,resulting in an obvious increase of sludge concentration.Since a high concentration of nitrate existed in the whole process and the pHvalue in Reactor 2^# was low,phosphorus removal is considered to be accomplished in a new way,unlike traditional EBPR.