单线态氧主导的天然铁电气石粒子电极降解茜素红的机理研究

Degradation mechanism of alizarin red by natural Fe-tourmaline particle electrode dominated by singlet oxygen

为克服粒子电极制备成本高、投加量大的问题,利用天然铁电气石粒子电极对典型蒽醌染料茜素红进行了快速有效降解。考察了外加电压、初始pH、染料初始质量浓度和电解质种类及浓度对茜素红降解率的影响。结果表明,最佳实验条件为外加电压为3.5 V、初始pH=5、NaCl质量浓度为4 g/L、初始染料质量浓度为20 mg/L。5次循环后铁电气石具有较高的循环稳定性。在该体系中,O_(2)在电气石表面转化生成O_(2)·-、1O_(2)活性物质,与电气石结构中的h+协同降解茜素红,可实现72.78%的COD去除率、44.85%的TOC矿化率。该方法可作为一种低成本、绿色的染料废水处理法。

In order to address the challenges associated with the costly preparation and significant dosage requirements of common particle electrodes,natural Fe-tourmaline is used as particle electrode for the rapid and effective degradation of alizarin red,a typical anthraquinone dye.The effects of applied voltage,initial pH,initial mass concentration of alizarin red,electrolyte type and electrolyte concentration on the degradation rate of alizarin red are investigated.The optimum experimental conditions are obtained as follows:applied voltage is 3.5 V,initial pH=5,NaCl is used as electrolyte with a mass concentration of 4 g·L^(-1),and initial mass concentration of alizarin red is 20 mg·L^(-1).Fe-tourmaline remains a high cyclic stability after five cycles.In this system,O_(2) is transformed into O_(2)^(·-)and 1O_(2)active substances on the surface of tourmaline,which synergistically degrades alizarin red with h+in the structure of tourmaline.The removal rate of COD can reach 72.78%and TOC mineralization rate can achieve 44.85%.Therefore,this method can be used as a low-cost and green method to treat with dye-containing wastewater.