改良型CAST工艺短程生物脱氮的实现与破坏  

Realization and Destruction of Shortcut Biological Nitrogen Removal in a Modified CAST Process

作　　者：马娟[1] 张伟[1] 宋相蕊 陈永志[1] 孙洪伟[1] 

机构地区：[1]兰州交通大学环境与市政工程学院,甘肃兰州730070

出　　处：《中国给水排水》2016年第1期11-16,共6页China Water & Wastewater

基　　金：国家自然科学基金资助项目(51168027;51168028);甘肃省科技计划项目(14RJZA093);甘肃省财政厅基本科研业务费资助项目(213065)

摘　　要：以改良型CAST反应器处理实际生活污水,研究了系统实现短程生物脱氮的条件及其稳定性。结果表明:控制曝气量为0.5 m3/h、温度为(28±0.5)℃、污泥龄为15 d,成功地在改良型CAST反应器内快速实现了短程硝化;继续降低曝气量至0.4 m3/h,短程硝化稳定维持了128个周期,在此阶段系统内亚硝态氮积累率均值为73.43%,最高可达86.08%,总氮去除率为69.35%,较全程硝化的脱氮效率提高了18.45%,且污泥沉降性能良好。研究还发现,降低进水总氮浓度会导致亚硝态氮积累率下降甚至破坏短程硝化,且短程硝化一旦被破坏,即使再次提高进水总氮至原浓度并调节温度和曝气量至最有利于短程硝化的条件,系统的短程生物脱氮性能在长期内仍不能恢复。Domestic sewage was treated by a modified cyclic activated sludge technology （CAST） reactor to investigate the conditions for the realization of shortcut biological nitrogen removal and its stability. The results showed that shortcut nitrification could be successfully realized in the modified CAST in a short time by controlling the aeration rate at 0.5 m^3/h, temperature at （28±0.5 ）℃ and sludge reten- tion time at 15 d. Shortcut nitrification could be stabilized for 128 cycles through reducing the aeration rate to 0.4 m^3/h. During the stabilization period, the average nitrite accumulation rate in the system was 73.43% and the highest accumulation rate was up to 86.08%. The removal rate of TN during the short- cut nitrification was 69.35%, which was 18.45% higher than that during the complete nitrification, and the system showed a good sludge settleability. It was also found that reducing the concentration of TN in the influent could result in a decrease of nitrite accumulation rate and even the destruction of shortcut ni- trification in the system. Nevertheless, once destroyed, Shortcut biological nitrogen removal performance of the system could not be recovered in a long term even by increasing the concentration of TN in the influent to the original extent and adjusting temperature and aeration rate in an optimized condition for shortcut nitrification.

关 键 词：短程硝化反硝化 改良型CAST工艺 亚硝态氮积累 破坏 

分 类 号：X703[环境科学与工程—环境工程]