石油化工洗罐废水预处理试验研究

Experimental study on pretreatment of tank-washing wastewater from petrochemical industry

石油化工洗罐废水具有石油类、CODCr、LAS浓度高且乳化严重等特点,为解决该废水对污水处理厂造成较大冲击的问题,需对其进行预处理。采用"IDAF气浮-SUPOX-高级氧化"组合工艺处理洗罐废水,考察了运行条件以及药剂投加量对洗罐废水处理效果的影响,当洗罐废水进水CODCr、SS、石油类以及LAS的质量浓度分别为71 200、40 205、4 133、343 mg/L时,工艺系统的最佳运行条件如下:IDAF气浮运行时PAM投加量为75mg/L;SUPOX运行时曝气量为5 m3/h,停留时间为2 h;高级氧化系统运行时n(H2O2)∶n(CODCr)=0.25∶1,经该组合工艺处理后出水CODCr、SS、石油类以及LAS的质量浓度分别为1 268.0、9.6、20.3、15.4 mg/L,满足设计要求且运行稳定。该组合工艺具有较强的抗冲击负荷性能,可有效解决石油化工洗罐废水对废水处理系统造成的水质冲击问题。

As tank-washing wastewater from petrochemical industry may greatly impact the equipments of wastewater treatment plant for its characteristics of high petroleum, CODCrand LAS concentration, and serious emulsification, to ensure the treatment effect, a pretreatment unit is required. Using IDAF air floatation-SUPOXadvanced oxidation combined process to treat tank-washing wastewater, the influences of operating condition and reagent dosage on the treatment effect were studied. The results showed that, when the mass concentrations of CODCr, SS, petroleum and LAS in the influent tank-washing wastewater were 71 200, 40 205, 4 133 and 343 mg/L respectively, the optimal operating conditions of the said system was as follows： the PAM dosage for IDAF air floatation was 75 mg/L, the aeration rate and HRT for SUPOX were 5 m^3/h and 2 h respectively, the n（H2O2） ∶n（CODCr） = 0.25 ∶ 1 for advanced oxidation. Through the treatment by the said combined process, the mass concentrations of CODCr, SS, petroleum and LAS in the effluent water were 1 268.0, 9.6, 20.3 and 15.4 mg/L respectively, which met the design requirement and the operation was stable also. It could draw a conclusion that the combined process had good anti-shock loading capability, which could effectively solve the problem of wastewater treatment system caused by the impact of tank-washing wastewater from petrochemical industry.