反硝化颗粒污泥处理不锈钢酸洗废水研究

Study on theTreatment of Stainless Steel Pickling Wastewater by Denitrifying Granular Sludge

采用以厌氧絮状污泥作为接种污泥的上流式厌氧反应器,通过调整其水力停留时间和水力条件等关键因素培养反硝化颗粒污泥,开展其对不锈钢酸洗废水脱氮研究。研究结果表明,上流式厌氧反应器以甲醇作为碳源运行42 d后,形成了成熟的反硝化颗粒污泥;成熟的反硝化颗粒污泥边缘清晰、表面包裹大量杆菌,单颗污泥沉降速率可达198~273 m/h,粒径为1~6 mm,反硝化速率最高可达2.79 gN/(gVSS·d);在反应器NO_(3)^(-)-N容积负荷为2.0~2.44 kg/(m^(3)·d)时,NO_(3)^(-)-N平均去除率为98.03%,NH_(4)^(+)-N平均去除率为89.76%,TN平均去除率为97.81%;最终出水的氨氮及总氮可同时满足《钢铁工业水污染物排放标准》(GB 13456-2012)的间接排放标准和《污水排入城镇下水道水质标准》(GB/T 31962-2015)的C级排放标准。本工艺相比传统反硝化工艺能够节约碳源30%左右。

By inoculating anaerobic flocculent sludge in the upflow anaerobic reactor,the denitrifying granular sludge(DGS)was cultured by adjusting key factors such as hydraulic retention time and hydraulic conditions.The denitrification of stainless steel pickling wastewater was studied.The results showed that mature denitrifying granular sludge was formed after 42 days of operation with methanol as the carbon source.The mature DGS has clear edges and a large number of rhabditiform bacteria on the surface.The settlement rate of a single DGS reached 198~273 m/h,with the particle size of 1~6 mm,and the denitrification rate reached the highest at 2.79 gN/(gVSS·d).When the NO_(3)^(-)-N volume load of the reactor was 2.0~2.44 kg/(m^(3)·d),the average NO_(3)^(-)-N removal rate was 98.03%,with the average NH_(4)^(+)-N removal rate of 89.76%,and the average total nitrogen(TN)removal rate of 97.81%.The final effluent NH_(4)^(+)-N and TN can meet both the indirect discharge standard of Water Pollutants Discharge Standard for Iron and Steel Industry(GB 13456-2012)and the Class C discharge standard of Wastewater Quality Standard for Sewage Discharge into Urban Sewers(GB/T 31962-2015).Compared with the traditional denitrification process,this process can save about 30%of carbon source.