喷射床电沉积法处理模拟含镍废水

为检验恒电流喷射床微粒电沉积法高效、低成本处理含镍废水的可行性,以实验室模拟酸性含镍废水为研究对象，进行了工艺条件优化研究。结果表明：①Ni²⁺去除率和电流效率随pH值的增大先升后降；电流值增大Ni²⁺去除率上升、电流效率下降；沉积液温度升高，Ni²⁺去除率和电流效率下降；微粒粒径越小，Ni²⁺去除率和电流效率越高；氮气的鼓入可提高电流效率和Ni²⁺去除率。②DO值随pH值和电流强度增大而增大，随温度升高而降低，氮气的鼓入可有效降低DO值。③氮气的鼓入主要通过降低沉积液的DO值来抑制沉积金属镍的返溶，也削弱了因浓差极化导致的Ni²⁺去除率和电流效率下降的问题。④Ni²⁺浓度为1 g/L的废水，在pH=4.5，微粒粒径为1.8 mm，电流强度为15 A，沉积液的温度为25 ℃，有氮气鼓入的情况下，电沉积180 min的Ni²⁺去除率为74.77%，平均电流效率为67.67%，比不鼓入氮气分别高28个百分点和16.66个百分点。由于电沉积可以直接得到金属镍单质，因此，从实践上讲，该方法具有显著的经济和环境效益,亦可作为离子交换或膜分离法前的预处理方法。

Treating Simulative Wastewater Containing Nickel by Spouted Bed Electro-deposition Method

In order to find out the feasibility in dealing with Ni²⁺ containing wastewater with constant current spouted bed particle electro-deposition method，the technical conditions optimization research has been conducted with simulated acid Ni²⁺ wastewater.The results are as follows：①with the increase of pH value，the removal rate of Ni²⁺ and current efficiency increased first and then decreased; with the increase of current value，the removal rate of Ni²⁺ increased，current efficiency decreased; both removal rate of Ni²⁺ and current efficiency decreased as the temperature increased; ②DO value increased with the increase of pH and current value，while decreased with temperature.Blowing nitrogen effectively reduced the DO value.③Blowing nitrogen prevented the nickel deposited back to dissolve，also weakened the concentration polarization which could result in the decline of the Ni²⁺ removal rate and current efficiency.④under the conditions of Ni²⁺ concentration 1 g/L，pH=4.5，particle size 1.8 mm，current intensity 15 A，electrolyte temperature 25 ℃ and blowing N₂ for 180 min，the removal rate of Ni²⁺ was 74.77%，the average current efficiency was 67.67%，which were higher by 28 and 16.66 percentage points than that without N₂ respectively.Since electro-deposition can directly obtain nickel metal from wastewater，this method has remarkable economic and environmental benefits in practice，and also can be set as a pretreatment method before ion exchange and membrane separation.