电絮凝-微纳米气泡臭氧氧化工艺处理高盐印染废水的研究

Study on treatment of high-salt printing and dyeing wastewater by electroflocculation-micro-nano-bubble ozone oxidation process

高盐印染废水具有色度大、可生化性差、水质水量不稳定等特点,以致难以通过传统生化方法得到高效处理。将微纳米气泡臭氧(O_(3))高级氧化工艺与电絮凝(EC)工艺组合处理高盐印染废水,探究2种工艺的耦合作用,并研究电流密度、盐浓度、pH等因素对组合工艺处理效果的影响。结果表明,单独EC法处理印染废水在一定程度有脱色和去除有机物的效果,但效率低。在相同条件下,EC和O_(3)同时处理(EC+O_(3))150 min与EC处理30 min后再经O_(3)处理120 min (EC→O_(3))过程相比,EC+O_(3)处理印染废水的效率更高,去除1 mg COD消耗的O_(3)仅为0.46~1.39 mg。随着电流密度和pH的升高,EC+O_(3)工艺的色度、UV254、COD和TOC去除率增加;盐浓度的增加对色度、UV_(254)、COD和TOC去除率影响不大。比较了O_(3)微纳米气泡工艺、高级氧化法H_2O_(2)/O_(3)、EC+O_(3) 3种方法对新疆和浙江实际印染废水的处理效果,并进行了经济性分析。3种微纳米气泡处理工艺的单位污染物电能消耗量(EE/O)由低到高为EC+O_(3)<H_(2)O_(2)/O_(3)<O_(3)。

High-salt printing and dyeing wastewater has the characteristics of high chromaticity,poor biodegradability and unstable water quality,which makes it difficult to be treated efficiently by traditional biochemical methods.Micro-nano-bubble ozone(O_(3))advanced oxidation process and electric flocculation(EC)process were combined to treat high-salt printing and dyeing wastewater,the coupling effect of the two processes was explored,and the influence of current density,salt concentration,pH and other factors on the treatment effect of the combined process was studied.The experimental results showed that EC alone could decolorize dyeing wastewater and remove organic matter to a certain extent,but the efficiency was low.Under the same conditions,the treatment efficiency of printing and dyeing wastewater by EC+O_(3) process was higher than that by EC→O_(3) process(EC treatment for 30 min→O_(3) treatment for 120 min),and the ozone consumed by removing 1 mg COD was 0.46-1.39 mg.With the increase of current density and pH,the decolorization rate,UV254,COD and TOC removal rate increased.With the increase of salt concentration,the decolorization rate,UV254,COD and TOC removal rate increased slightly.The effects of ozone micro-nano-bubble process,H_(2)O_(2)/O_(3) of advanced oxidation process and EC+O_(3) processes on the treatment of actual printing and dyeing wastewater in Xinjiang and Zhejiang were compared,and the economic analysis was carried out.The electrical energy per order(EE/O)value of each stage of the three micro-nano-bubble treatment processes was EC+O_(3)<H_(2)O_(2)/O_(3)<O_(3) from low to high.