活性炭吸附处理电镀废水中的EDTA

Adsorption of EDTA in electroplating wastewater by activated carbon

采用颗粒活性炭对模拟废水中EDTA进行批式吸附实验，在实验中考察了恒温振荡器的振荡速度、温度、pH值等因素对吸附的影响，同时探讨了吸附等温线模型和吸附动力学模型。实验结果表明，在25％时活性炭对EDTA的吸附平衡时间为40h。在pH值为5．0、温度为25℃、振荡器振荡速度为200r／min、活性炭粒径为1～2mm、活性炭加入量为10g／L的情况下，EDTA的浓度在48h内由368．8mg／L降低至76．34mg／L，对应的COD值从305．9mg／L降低为67．21mg／L，去除率达到了79．3％。活性炭对EDTA的吸附符合Langmuir吸附等温线模型，其吸附行为可以用准二级吸附动力学模型来描述。

In this study, granular activated carbon was used to adsorb EDTA from simulated wastewater by conducting series of batch experiments. Several influencing factors were evaluated which included shaking speed of constant temperature oscillator, water temperature and pH value. In addition, the adsorption equilibrium isotherms model and adsorption kinetics model were investigated. The results show that it takes 40 h for the adsorption of ED- TA to reach equilibrium at 25℃. EDTA is reduced by 79.3% within 48 h, from 368.8 mg/L to 76.34 mg/L, un- der the conditions of pH value of 5.0, temperature of 25℃ , shaking speed of 200 r/min, grain size of 1 -2 mm, activated carbon dosage of 10 g/L. Meanwhile COD value decreases from 305.9 mg/L to 67.21 mg/L. Further- more, the adsorption of activated carbon on EDTA is best fitted with Langmuir adsorption model, the kinetic process of adsorption can be described by the pseudo-second-order kinetic model.