脉冲电源电解处理含氰含银电镀废水

Silver recovery and cyanide removal from silver-plating wastewater using pulse-electrolysis

利用脉冲电源从含氰含银电镀废水中回收银和去除氰,对比了脉冲电源与直流电源对含氰镀银废水的处理效果,系统研究了脉冲电源的电解电压、占空比和脉冲频率等参数对电能消耗、银回收率和除氰率的影响。结果表明,脉冲电源较直流电源能更加有效降低阳极的超电位,减少电极的极化,从而降低槽电压,进而有效地降低电能消耗。脉冲电源的优化参数是:脉冲电压2.0V,脉冲频率1200Hz,占空比50%。在循环流速100ml.min-1,pH值10～11,曝气速率1.0L·min-1的实验条件下,通入电解电压2.0V、脉冲频率1200Hz以及占空比50%的脉冲电源,电解2.0h后,银回收率高达99%,除氰率达到86%。

The objective of the present study was to recover silver and remove cyanide from silver-plating wastewater using the novel pulse-electrolysis technique.The efficiency of silver recovery and cyanide removal,as well as power consumption was discussed in terms of pulse voltage,pulse duty factor,and pulse frequency.The optimum condition for silver recovery（99%）and cyanide removal（86%）was as follows：electrolysis voltage of 2.0 V,pulse duty factor of 50%,pulse frequency of 1200 Hz and electrolysis time of 2.0 h.In addition, compared with the conventional direct current electrolysis, the pulse-electrolysis technique showed such advantages of lower polarization of electrodes, lower overvoltage, and lower tank voltage. Thus, the presented method has a potential application for electroplating wastewater treatment.