用CO_2改性碱渣废水强化炼油废水的硝化效能

Enhancement of oil refining wastewater nitrification efficiency by CO_2 modified alkaline wastewater

针对炼油废水缺乏碱度而硝化效能受限问题,以CO2曝气处理后的改性碱渣废水为碱度补充剂,按一定配比加入炼油废水好氧阶段以强化硝化效能.实验结果表明：经流量为1 L/min的CO2连续曝气处理5h后,碱渣废水pH可降至7.2 ～ 7.8,钙元素质量浓度可降低90.65％,并去除了部分汞、砷等有毒重金属;将该改性碱渣废水以1∶99的体积比加入炼油废水并进行生化处理,COD去除率可达90.2％;相较于未补充碱渣的炼油废水,出水ρ （NO3-N）提高25％～ 30％,硝化细菌菌群密度增加52％,污泥絮体形态结构未发生改变.

Aiming at the problem of limited nitrification efficiency of alkalinity-lacking refinery wastewater, the alkaline wastewater modified by CO2 aeration treatment was used as alkalinity supplement and added into the refinery wastewater at aerobic stage by a certain proportion to enhance the nitrification efficiency. The experimental results show that： After continuous CO2 aeration treatment with 1 L/min of flow for 5 h, pH of alkaline wastewater is decreased to 7.2-7.8, the mass concentration of calcium element is reduced by 90.65%, and some heavy metals such as mercury and arsenic are removed; When the modified alkaline wastewater is added into the refinery wastewater with 1 ： 99 of volume ratio for biochemical treatment, the COD removal rate can reach 90.2%; Comparing with the refinery wastewater without alkaline wastewater, the effluent p （NO3--N） is increased by 25%-30%, the density of nitrifying bacteria is increased by 52%, and the morphology and structure of sludge floc are not changed.