控制pH实现短程硝化反硝化生物脱氮技术

Nitrogen removal from wastewater via shortcut nitrification-denitrification achieved by controlling pH

采用序批式活性污泥法,在温度为28±1℃的条件下,通过控制反应器内初始pH为7.8～8.7开发了一种新型短程硝化生物脱氮工艺.试验结果表明:经过25 d的运行,曝气结束时出水中主要以亚硝酸盐为主,硝酸盐氮在4 mg/L以下,亚硝酸盐累积率达90%以上;在整个硝化期间游离氨(FA)质量浓度都在0.52～4.72 mg/L,均在抑制硝酸菌活性的阈值范围内.因此,控制pH实现短程硝化反硝化生物脱氮工艺的机理是利用反应体系内的高pH和高游离氨浓度对硝酸菌产生抑制,从而在硝化过程中产生亚硝酸盐积累.

A novel technology for nutrient removal from wastewater was developed using the sequencing batch reactor （SBR） activated sludge process. Nitrogen removal can be achieved at 28±1℃ via shortcut nitrification and denitrification by controlling the pH value at 7 8 - 8 7. The experimental results indicated that nitrite was the main element in the effluent when aeration was ended after twenty -five days, that nitrate was less than 4 rag/L, and that the nitrosation rate （NO2^- - N/NOx^- - N） was more than 90%. In addition, as free ammonia （FA） concentration was always at 0 52 -4 72 mg/L during nitrification, it would inhibit the nitrite oxidizers. So the shortcut mechanism achieved in that using the inhibition of the nitrite oxidizers to the nitrite. nitrification- denitrification by controlling raise pH value and free ammonia results in the pH value is accumulation of