辉光放电电解等离子体降解水中阳离子红XL-GRL

Degradation of cationic red XL-GRL in aqueous solution by using glow discharge electrolysis plasma

针对染料废水色度高、难生物降解等问题,提出了用辉光放电电解等离子体(GDEP)技术降解染料废水阳离子红XL-GRL的方法。研究了放电电压、溶液浓度对脱色率的影响;测定了GDEP产生的活性物质以及降解过程中溶液的电导率、pH和TOC去除率的变化;分析了降解中间产物成分。结果表明,在600 V电压下,GDEP产生了HO?、H?、O?等高活性物质,他们可使染料分子在130 min内的脱色率达到93.32%,在120 min内TOC去除率达到了65.80%。降解过程中产生了大量带电离子及酸性中间产物。推测可能的降解机理是,阳离子红XL-GRL分子在HO·作用下双键断裂,生成酚类等产物,接着继续降解为中间产物醌,并进一步氧化为小分子有机酸,最终矿化为CO_2、H_2O和简单的无机离子。GDEP在有机染料废水处理方面具有一定的应用前景。

For high chroma and refractory dye wastewater, a glow discharge electrolysis plasma(GDEP)technique was used to degrade cationic red XL-GRL in dye wastewater. The effects of discharge voltage and dye concentration on the decolorization rate were investigated. The active species produced by GDEP, solution conductivity, pH, TOC removal rate during degradation process were determined, as well as the intermediate products. The experimental results showed that highly active species such as HO·, O· and H· are produced at the 600 V, which could lead to 93.32% dye decolorization after 130 min treatment, and 65.80% TOC removal after 120 min treatment. A large number of charged ions and acidic intermediates were produced accordingly.Moreover, a possible degradation mechanism was that the double bonds in cationic red XL-GRL molecular were broken under the action of HO·, and phenols were formed. They were degraded into quinones, and further oxidized into small-molecule organic acids. Finally, these acids were completely mineralized into CO2, H2 O and simple inorganic salt. As an advanced oxidation technique, GDEP has a promising application prospect in organic dye wastewater treatment.