短程硝化/厌氧氨氧化工艺处理氧化铁红废水

Treatment of Iron Oxide Red Wastewater by Partial Nitritation/Anammox Process

采用短程硝化/厌氧氨氧化工艺对氧化铁红废水进行脱氮处理,分析沸石曝气生物滤池(Z-BAF)亚硝化的可行性,以及碱度和氨氮的比值对亚硝化作用的影响,并对比了Na_2CO_3和NaHCO_3作为碱度供体的经济成本。结果表明,废水经Z-BAF生化处理后,可实现氨氮的部分亚硝化,通过调节进水碱度能够控制氨氮的亚硝化率,使出水NO_2^--N/氨氮值稳定在1. 0～1. 4之间。以Na_2CO_3作为碱度的来源,采用两级Z-BAF分步投加碱度法,可以避免一次投加导致pH值过高问题,从而降低对生化反应的影响,并且使用Na_2CO_3代替常用的NaHCO_3作为碱度供体可节省约一半的成本。反应器稳定运行阶段,一级Z-BAF的亚硝态氮产率为0. 36 kg/(m^3·d),二级Z-BAF的亚硝态氮产率为0. 67 kg/(m^3·d),厌氧氨氧化反应器经过100 d运行后,总氮去除率可稳定在70%以上。

Partial nitrification/Anammox process was applied for the nitrogen removal of iron oxide red wastewater.The feasibility of nitritation in zeolite biological aerated filter(Z-BAF)was investigated,and the effect of alkalinity/NH4+-N ratio on nitritation rate was analyzed.The cost of Na2CO3 and NaHCO3 served as alkalinity donors was compared.The results showed that partial nitritation was achieved after NH4+-N was oxidized in Z-BAF.The nitriation rate of NH4+-N could be controlled by adjusting the influent alkalinity,and the effluent NO2--N/NH4+-N ratio was consistently between 1.0 and 1.4.High p H value caused by one-step addition could be avoided by using a two-step addition method in Z-BAF process when Na2CO3 served as alkalinity donor,and it also reduced the impact on biochemical reaction.Using Na2CO3 instead of NaHCO3 as alkalinity donor could save half the cost.The nitrite production rate(NPR)of the first and second stage Z-BAFs were 0.36 kg/(m3·d)and 0.67 kg/(m3·d)during stable operation phase.The total nitrogen(TN)removal rate kept above 70%in Anammox reactor after 100 days of operation.