混凝-热活化过硫酸盐氧化处理金属切削液废水

Treatment of metal cutting liquid wastewater by thermal activated persulfate combined with coagulation

针对机械加工产生的金属切削废液COD浓度高、成分复杂且生化性差的问题,用热过硫酸盐法结合混凝对其进行降解处理,采用单因素实验法对影响处理效果的各因素进行研究.结果表明,用PAC对废液进行混凝破乳试验中,最佳投加量为20g/L,pH为5时,Zeta电位由-60.59mV升至-38.68 mV,絮凝效果增强,混凝处理后COD的去除率为76.36%;经过混凝后,再进行热过硫酸盐法处理,过硫酸钾的投加量为PS∶12COD0=2,温度90℃,pH 6~7之间,反应时间为4h,COD的去除率为81.73%,且UV254去除率和COD去除率呈现一定的对应关系,出水COD为1 463.43mg/L.研究表明,热活化过硫酸盐结合混凝对金属切削废液具有很好的降解效果,提高了后续处理的可生化性.

Aiming at the problems of high COD concentration, complex composition and poor biodegradability of the cutting waste liquid produced by mechanical processing, the degradation process is carried out by thermal persulfate method combined with coagulation, and the factors influencing the treatment effect are studied by single factor experiment.The experimental results show that the optimum dosage of PAC is 20 g/L,pH is 5, Zeta potential increases from -60.59mV to -38. 68 mV, which enhances the flocculation effect.The removal rate of COD after coagulation is 76. 36 %.After coagulation and the thermal persulfate treatment, the dosage of potassium persulfate is PS ： 12COD=2, the temperature 90 ℃, pH 6-7, reaction time 4 hours, COD removal rate reaches 81.73%; and UV254 removal rate and COD removal rate show a certain correspondencel the effluent COD is 1 463.43 mg/L. The results show that the thermal activation of persulfate combined with coagulation has good degradation effect on metal cutting waste liquid, and the biodegradability of the subsequent treatment is improved.