转化过程[精选].docVIP

内循环生物流化床硝化过程的选择特性研究 王志盈　袁林江　彭党聪　刘超翔 　　摘　要：　采用下向流内循环生物流化床反应器(DBFB)，分别在高浓度氨和低溶解氧条件下探讨了亚硝化过程的稳定性。试验结果表明：通过高浓度游离氨对硝化菌选择性抑制所获得的亚硝酸盐积累是不稳定的；在0.5～1.0 mg/L溶解氧下，DO成为增殖的限制基质，可实现亚硝酸盐的稳定积累；当进水NH3-N为300 mg/L时，出水NH3-N＜20 mg/L；在保证氨氮去除率＞90%的前提下，使出水硝态氮中亚硝酸盐比例稳定在80%以上。亚硝化选择过程完成后亚硝酸菌成为生物膜中的优势菌群。　　关键词：　DBFB；　硝化；　亚硝酸盐积累；　生物脱氮　　中图分类号：　X703　　文献标识码：　A　　文章编号：　1000-4602(2000)04-0001-04 Experimental Study on the Selection Characteristic of Nitrificationin Down-Flow Biological Fluidized Bed (DBFB) WANG Zhi-ying,　YUAN Lin-jiang,　PENG Dang-cong,　LIU Chao-xiang(School of Environ. and Munic. Eng., Xian Univ. of Architec. and Tech., Xian710055, China) 　　Abstract：　A DBFB reactor was used to discuss the stability of nitrozation under high concentration of ammonia and low concentration of DO respectively. The experimental results showed that the nitrite accumulation obtained from selective inhibition of high concentration free ammonia to nitrifier was unstable. DO became growth-limiting substrate, and nitrite accumulation could be realized at DO concentration of 0.5～1.0 mg/L. When NH3-N concentration in influent was 300 mg/L, that in effluent was lower than 20 mg/L. Under prerequisite for ammonia removal efficiency of more than 90%, the ratio of nitrite to the sum of nitrite and nitrate in the effluent was above 80%. Nitrosomonas dominated in the biofilm after accomplishment of nitrozation selection.　　Keywords:　DBFB;　nitrification;　nitrite accumulation;　biological nitrogen removal 　　在传统硝化—反硝化脱氮过程中, 从硝酸盐(NO-3)或亚硝酸盐(NO-2)都可以进行反硝化，而硝化过程中由NO-2转化为NO-3要消耗一定的溶解氧,然后在反硝化过程中NO-3再转化为NO-2的重复转化要消耗更多的有机碳源。如果控制这一转化过程,使NO-2全部或大部分不转化成NO-3,由NO-2直接反硝化,就形成了所谓的短程硝化—反硝化。其优点有:①需氧量减少了25%左右,可降低能耗。②反硝化过程中有机碳源需要量减少40%左右。③在高氨环境下,NH+4的硝化速率和NO-2的反硝化速率均比NO-2的氧化速率和NO-3的反硝化速率快,因而水力停留时间可缩短,反应器容积也可相应减小。④亚硝酸菌和硝酸菌的表观产率系数分别为0.04～0.13 gVSS/gN和0.02～0.07 gVSS/gN,NO-2反硝化菌和NO-3反硝化菌表观产率系数分别为0.345 gVSS/gN和0.765 gVSS/gN,因此短程硝化—反硝化在硝化过程中可少产污泥33%～35%左右,在反硝化过程中可少产污泥55%左右。由此可见，对于焦化、石化、化肥以及垃圾渗滤液等高氨氮、低碳源废水的生物脱氮处理，短程硝化—反硝化具有重要的意义。　　实现短程硝化—反硝化的关键步