包埋活性污泥和反硝化污泥短程硝化反硝化脱氮

以模拟废水为对象,在传统的流化床反应器内,将活性污泥和经驯化的反硝化污泥按适当比例混合后,用聚乙烯醇(PVA)加适当添加剂将其包埋,并对短程硝化反硝化脱氮进行了研究.结果表明,在进水NH4+-N平均为53.60mg/L,COD为281.19mg/L,HRT12h,调控温度、溶解氧、pH等,出水亚硝化率和TN去除率分别可达95%和85%以上,短程硝化反硝化脱氮较理想.当进水COD含量从150mg/L增加到750mg/L,TN去除率从73.66%提高到96.79%.适合包埋颗粒短程硝化反硝化脱氮的最佳溶解氧浓度约为4.0mg/L.当pH一直维持在8.0左右,温度从30℃降到25℃过程中,短程硝化反硝化并未遭破坏.当温度维持在25℃,pH从8.0降到7.5,连续运行约5个周期后,短程硝化反硝转变为全程的硝化反硝化.

Shortcut Nitrification and Denitrification Using Immobilized of Mixed Activated Sludge and Denitrifying Sludge

Shortcut nitrification and denitrification in a traditional fluidized bed reactor with artificial domestic wastewater was studied using polyethylene(PVA)gel beads,in which activated sludge and denitrifying sludge were entrapped.The results showed that under the influent COD was 281.19mg/L and NH+4-N was 53.60mg/L,nitrite accumulation and TN removal ratio could reach to nearly 95% and 85%,respectively,by adjusting the temperature,DO and pH value in the process,suggesting simultaneous shortcut nitrification and denitrification occurs in the experiment.TN removal efficiency increased from 73.66% to 96.79% when influent COD concentration changed in the range of 150mg/L to 750mg/L,and it also could promote NH+4-N removal slightly.The best dissolved oxygen concentration to microorganisms was about 4.0mg/L.When the temperature decreased from 30℃ to 25℃,pH value was at about 8.0,shortcut nitrification and denitrification was still normal.However,if changed the pH value from about 8.0 to 7.5,at 25℃,five treatment cycles later shortcut changed to complete nitrification and denitrification.