穿流式电解-吸附原位耦合强化染料降解与机理分析

In Situ Coupling Enhancement of Dye Degradation by Through-Flow Electrolysis-Adsorption and Its Mechanism Analysis

为了提高电化学氧化效率,在阴阳两极间隙填充不同类型的吸附材料,设计了一种原位集成的穿流式电解-吸附耦合反应器(EA-R),并选取了典型染料酸性红G(ARG)作为模拟污染物。结果表明,电解耦合PANI/TiO_(2)吸附对ARG模拟废水呈现较好的处理效果,脱色率和COD去除率远高于单独电解处理。同时,发现电解和PANI/TiO_(2)吸附之间存在协同效应。将四种常用填料(石英砂、天然沸石、焦炭和活性炭)分别与PANI/TiO_(2)均匀混合,以降低废水穿流阻力,提高EA-R渗水能力。结果表明,四种电解-吸附模式均具有协同效应,其中填充PANI/TiO_(2)+焦炭的EA-R对废水脱色和COD去除呈现最大协同系数(Sc),分别为62.5%和61.7%,同时相比与单独电解处理单位COD能耗下降65.3%。UV-Vis、FT-IR和GC-MS分析表明,ARG在电解过程中的降解机理非常复杂,包括氧化还原、电化学聚合、相互反应等,其中ARG分子偶氮双键更易受到破坏,导致废水脱色显著。

To improve the efficiency of electrochemical oxidation,an in-situ integrated through-flow electrolysis adsorption coupling reactor (EA-R)was designed by filled different types of adsorption materials in the gap between anode and cathode.The typical dye acid red G (ARG) was selected as the simulated pollutant.The results showed that electrolysis coupled with PANI/TiO_(2)adsorption presented a better treatment effect on ARG simulated wastewater,and the decolorization rate and COD removal rate were much higher than that of single electrolysis treatment.Meanwhile,a synergistic effect between electrolysis and PANI/TiO_(2)adsorption was found.Four common fillers (quartz sand,natural zeolite,coke,and activated carbon) were evenly mixed with PANI/TiO_(2)to reduce the flow resistance of wastewater and improve the water permeability of EA-R.The results showed that all four electrolysis-adsorption modes had synergistic effects,in which EA-R filled with PANI/TiO_(2)+ coke showed the maximum synergistic coefficient(Sc) for wastewater decolorization and COD removal with 62.5% and 61.7% respectively.Compared with the single electrolysis,the energy consumption of per unit COD was reduced by 65.3%.Meanwhile,the degradation mechanism of ARG during electrolysis-adsorption process was very complex,including oxidation-reduction,electro-polymerization,and mutual reaction,etc.,among which the azo double bond of ARG molecule is more easily damaged,leading to significant decolorization of wastewater.