电吸附工艺用于焦化废水深度处理的中试

采用电吸附除盐工艺对山西焦化厂的焦化废水进行中试深度处理. 结果表明:在进水电导率为3 680 μS/cm,工作电压为1.2 V,流量为120 L/h,吸附时间为30 min的条件下,出水平均电导率为1 530 μS/cm,除盐率为57.8%；ρ(COD_Cr)由74.8 mg/L降至29.4 mg/L,平均去除率为60.7%. 电吸附工艺对废水中的SO₄2-、Cl-、Ca2+、NH₃-N以及有机物亦有较好的去除效果,出水水质基本满足GB 50050—2007《工业循环冷却水处理设计规范》中敞开式循环冷却水作为系统补充水的水质要求. 电吸附去除有机物的机理主要为物理吸附,利用带电极板对带电基团的有机物进行富集浓缩. 工艺运行的最佳条件:工作电压为1.2 V,进水流量为120 L/h,此时电吸附除盐和除有机物效果最好. 

Pilot Study on Desalination of Coke Wastewater by Electro-Absorption Technology

Recent advances in coke plant wastewater treatment around the world are systematically introduced. Considering the shortcomings of traditional approaches, new methods and technologies have been proposed to treat coke plant wastewater. Electro-absorption technology can greatly enhance the treatment applicability and capability of the existing equipment. In addition, electro-absorption technology is more suitable for wastewater treatment of coke plants in China. The electro-absorption technology was used for advanced purification of coke plant wastewater from Shanjiao in a pilot-scale study. Experimental results showed that under the conditions of influent average conductivity 3680 μS/cm, electrode voltage 1.2 V, flow rate 120 L/h, effluent average conductivity 1530 μS/cm and desalinization rate 57.8%, COD_Cr was reduced to 29.4 mg/L from 74.8 mg/L, with average desalinization rate of 60.7%. The results indicate that electro-absorption technology was well suited for removal of sulfate, chloride and ammonia. The effluent water can be directly used to circulate water. The mechanism of electro-absorption for removal of organic matter was mainly physical absorption, using the charged plate to enrich instead of degrade the organics. The desalination effect was best when the optimum voltage of electro-sorb equipment was 1.2 V and the optimum flow rate was 120 L/h.