SBR工艺处理高质量浓度尿素废水短程硝化特性

为实现短程脱氮技术处理高质量浓度尿素废水,通过采用SBR工艺考察反应过程中pH、曝气时间、尿素容积负荷对高质量浓度尿素废水短程硝化特性的影响.结果表明:用SBR工艺处理高质量浓度尿素废水效果稳定,出水中含有大量的亚硝酸氮,发生了短程硝化;当pH在7～10的范围内时,亚硝酸盐积累率均在90%以上;在试验条件下,曝气时间对短程硝化过程影响不大,尿素水解反应成为限速步骤;尿素容积负荷没有影响亚硝酸盐氮的积累率,当进水尿素容积负荷控制在1.13 kg/(m3.d)以下时,能够获得较高的尿素去除率和氨氮转化率.高浓度尿素废水处理中短程硝化脱氮过程更容易实现.

Short-cut nitrification characteristics in treating wastewater with high-concentration urea with SBR

In order to achieve nitrogen removal via nitrite directly in treating wastewater with high-concentration urea,the influences of pH value,aeration time and CO(NH2)2 volume loading on the short-cut nitrification characteristics were investigated using SBR.The results showed the feasibility to treat wastewater with high-concentration urea by using SBR.Urea was converted into nitrite mostly in the effluent and then short-cut nitrification occurred.Controlling the pH value in the range of 7-10,the nitrosation rate(NO2-N/NOx-N) of more than 90% was achieved.In the experimental conditions,aeration time had little effect on the nitrite accumulation,and CO(NH2)2 hydrolyzation became the limit step.The CO(NH2)2 volume loading had no effect on the nitrite accumulation,but when it was controlled below 1.13 kg/(m3·d),higher CO(NH2)2 removal rate and ammonium nitrogen transformation rate were obtained.It is easy to achieve nitrogen removal via short-cut nitrification in treating wastewater with high-concentration urea.