泡沫铜气体扩散电极处理活性艳红废水

Treatment of Reactive Red waste water by a gas diffusion electrolysis method using copper foam electrode

采用铜基泡沫材料作为阴极,并根据泡沫材料电阻小、强度高、孔隙多的特点设计气体扩散电极,开发了一套基于铜基泡沫材料的气体扩散电解废水处理方法.实验结果表明,该方法在电解电压仅为1.65 V时,120 min内原位生成14.29 mg·L-1的H2O2.采用该系统对活性艳红废水进行降解,结果表明其在电解电压为2 V时即可快速高效地降解活性艳红X-3B模拟染料废水,120 min内模拟废水色度去除率达96.19%,色度被快速消除.UV-Vis与LC-TOF MS检测结果表明,降解过程中,萘环、三嗪结构及较稳定的苯环均被同步快速降解.该方法所需降解电压较低,只有2 V,而普通电解方法通常需8—25 V,能耗显著下降.这种低电压气体扩散电极电解不仅极大地抑制了水的无效电解,由于产生了·OH,还能维持相对高的有效氧化还原电位,高效降解污染物,是一种高效低耗的电化学水处理方法.

Copper foam material was introduced and used as the gas diffusion cathode in this study. This electrode has low electrical resistivity, good physical strength, and high porosity. Based on these features, a gas diffusion electrolysis waste water treatment method was developed. According to the experimental data, copper foam electrode was extremely good for H202 generation on the cathode in gas diffusion electrode reactor, and 14.29 mg·L^-1of H202 was detected in 120 min at 1.65 V which is extremely low comparing with previous research. The gas diffusion electrode reactor using copper foam cathode degraded Reactive Red X-3B rapidly. Decoloration of 96. 19% was achieved in 120 min only under 2 V. The structures of naphthalene nucleus, triazine ring and benzene ring, were broken up simultaneously during the degradation according to the result of UV-vis absorption spectra and LC-TOF MS. The energy consumption of the new reactor was much lower than traditional electrochemical reactor due to its low electrolysis voltage of 2 V, much lower than previous voltages of 8--25 V. At this voltage, the uneffetive electrolysis of H20 was widely inhibited. However, the degradation efficiency was still high because of the high reactive intermediates of · OH. This method is promising for low-cost and high efficient waste water treatment.