高氨氮猪场废水的亚硝酸型脱氮研究(英文)

Removing the Nitrogen from Highly Nitrogenous Piggery Wastewater via Nitrite

猪场废水脱氮处理前一般要经过厌氧消化处理,完全厌氧消化能去除废水中大部分有机物,但这同时降低了废水中的COD/NH+4 N(1～3).根据厌氧消化四阶段理论,控制厌氧消化到水解或产乙酸阶段,使废水中的COD/NH+4 N维持在较高的水平(7～10).为后续脱氮处理创造条件.本实验对比分析了运用缺氧/好氧SBR工艺处理这两种COD/NH+4 N不同的废水的脱氮效果,实验结果表明:两者的脱氮过程都是通过短程硝化反硝化实现的,反应器中的NH+4 N浓度和pH值是控制亚硝酸型硝化的重要因素,经过部分厌氧消化的废水由于保持了较高的COD/NH+4 N脱氮效果明显好于完全厌氧消化废水,NH+4 N去除率达到98%以上,但出水反硝化不完全,投加乙酸钠后出水NO-x N减少到10—20mg/L,投加量以275mg/L为宜.

Anaerobic digestion is commonly used to remove the organic matter from the piggery wastewater. Complete digestion can remove most of the organic matters in the wastewater, but this can also lower the COD/NH^+_4-N ratio(1～3). Based on the theory of two-step digestion, we can keep high COD/NH^+_4-N ratio(7～10) in the wastewater by stopping the digestion at the step of hydrolysis, which benefits the denitrification later. Anoxic/Aerobic SBR was used to treat these two kinds of wastewater. In the experiment nitrite nitrification/denitrification was found. The study results indicated that COD/NH^+_4-N ratio was an important factor for nitrogen removal. And the nitrogen removal of partly digested wastewater was more efficacious than that of the completely digested wastewater. Further more the effluent COD concentration was also lower.