有机碳源环境下亚硝酸盐的积累

Nitrite Accumulation in Ammonia-rich Organic Wastewater

采用CSTR反应器实现SHARON过程,考察了有机碳源存在下亚硝酸盐的积累过程,着重研究了当温度35℃、DO1.5-2mg/L、HRT=1d、进水pH值为8时,C/N对亚硝酸盐积累及出水NO2^- -N∶NH4^＋ -N的影响。结果表明,当进水中NH4^＋ -N浓度为360mg/L,C/N不超过0.42时,有机碳源的存在有利于亚硝酸盐的积累；在C/N0.17-0.34范围内,SHARON反应器出水适合后续ANAMMOX进水的要求；加入有机碳源后pH值降低0.2-0.4,当C/N不超过0.5时,SHARON反应器出水pH值均处于ANAMMOX的适宜范围内；在C/N为0-0.5范围内,随C/N的增加COD去除率从约90%大幅降低至约44%后又大幅提高至约82%。加入有机碳源后,由于异养菌的生长污泥浓度以及污泥中有机物含量升高,形成了紧密的絮状结构的污泥。

Nitrite accumulation in CSTR reactor for the artificial ammonla-rich organic wastewater was studied in this paper. It was focused that the effect of C/N to nitrite accumulation and NO2^-N：NH4^＋ -N in the effluent under the condition of 35℃, dissolved oxygen（DO） 1.5-2 mg/L, hydraulic retention time（HRT） 1 day and pH 8. The resuhs showed that organic carbon was benefit to nitrite accumulation when C/N was lower than 0.42 with NH4^＋ -N concentration being 360 mg/L;The suitable C/N for SHARON-ANAMMOX process was in the range of 0.17-0.34;The pH value decreased 0.2-0.4 while organic carbon was added to the artificial ammonia-rich wastewater, the pH value of the effluent of SHARON reactor was suitable for ANAMMOX when C/N was lower than 0.5. With C/N increased, the COD removal rate decreased from 90% to 44% and then stabilized at 82% , which was correlated to an increase of both biomass and organic content increased while organic carbon was added to the artificial ammonia-rich wastewater which can be attributed to the heterotrophic bacteria, at the same time small flocks was formed.