某铁路车辆厂含油废水混凝预处理试验研究

Study on Coagulation Pretreatment of Oily Wastewater from a Railway Rolling Stock Factory

西北某车辆厂含油废水为达到回用水要求,需对其进行深度处理。混凝作为预处理,其效果好坏直接影响气浮及精细过滤,为此进行了影响混凝效果因素的正交试验。通过研究确定出适合该厂水质的混凝预处理控制条件为：混凝剂种类为PAC（I）,投加量为30 mg/L,搅拌速度250 r/min,搅拌时间90 s,助凝剂用量为0.4 mg/L。使混凝后出水浊度、COD、油分别在4.5 NTU、55 mg/L、6.0 mg/L左右,与原来混凝后出水浊度10~26 NTU、COD60~92 mg/L、油7.4~10.6 mg/L相比有较大提高,为后续处理作了稳定可靠地保。

The oily wastewater from a railway rolling stock factory in the northwest of China is difficult to deal with.The current process can not reach the reuse standard,so the paper studied on an advanced treatment.As a pretreatment,the result of coagulation will affect flotation and fine filtration directly,so the paper had an orthogonal test about the influence of factors in coagulation.By research,the condition suitable for the quality of the water have been found： the best coagulant is PAC（I）,the dosage,stirring speed,stirring time and the dosage of coagulant aid was 30 mg/L,250 r/min,90 s and 0.4 mg/L respectively.The experiment results showed that the index for turbidity,COD and oil can reach 4.5 NTU,55 mg/L and 6.0 mg/L respectively,compared before10~26 NTU,60~92 mg/L,7.4~10.6 mg/L,the removal efficiencies have been greatly increased,and the result will be a reliable guarantee for the subsequent treatment.