UV_(185)对偶氮染料酸性红G的降解机理研究  

Mechanism of Degradation of Azo-dye ARG by Using UV_(185)

作　　者：陈徐庆 唐玉朝[1] 伍昌年[1] 黄显怀[1] 王坤[1] 马雪雨 冯琪瑞 CHEN Xuqing;TANG Yuchao;WU Changnian;HUANG Xianhuai;WANG Kun;MA Xueyu;FENG Qirui(Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]安徽建筑大学,环境污染控制与废弃物资源化利用安徽省重点实验室,安徽合肥230601

出　　处：《环境科学与技术》2023年第4期141-151,共11页Environmental Science & Technology

基　　金：国家自然科学基金项目(51978003);安徽省自然科学基金项目(2208085US20)。

摘　　要：该文以UV_(185)为光源,研究紫外高级氧化技术对印染废水中酸性红G(ARG)的光降解反应机理。结果表明:UV_(185)对ARG降解具有显著效果,远远优于UV254光源,光照20 min后降解率可达97.4%。光照功率增加对ARG降解效果显著。酸性条件对ARG的降解速率有提升作用,碱性条件有抑制作用,pH为3.0、6.7、9.0、11.0时,反应动力学常数分别是0.261、0.174、0.151、0.093 min^(-1)。降解反应动力学过程符合准一级动力学模型,R^(2)>0.990。自由基捕获实验说明UV_(185)光照中产生的活性物种·OH和^(1)O_(2)对ARG降解贡献程度较大,而·O_(2)_(-)无贡献。台式电子顺磁共振波谱仪检测到·OH和^(1)O_(2)存在,未检测到·O_(2)_(-)。CO_(3)^(2-)、Cl^(-)对ARG的降解存在着明显的抑制作用,各加入10 mmol/L时,20 min降解率分别降至对照试验的71.0%和80.7%;NO_(3)^(-)和SO_(4)^(2-)对降解过程无明显影响。印染助剂柠檬酸钠、十二烷基苯磺酸钠的存在均显著阻碍ARG的去除。H_(2)O_(2)的存在能显著加快ARG的降解。根据UV-Vis吸收光谱显示,509 nm处吸收峰的强度不断减弱,ARG分子结构遭到严重破坏。在ARG降解过程中,共检测16种主要降解产物并提出了可能的转化路径。总有机碳数据显示,在30 min时ARG矿化度达到49.4%。This paper reports on a laboratory experiment of azo-dye photodegradation by use of UVias as a light source.Initially,the simulated waste-water solution containing ARG(acid red G)was prepared and irradiated by UVis light,then ARG degradation was tested and the degradation rates was measured while adjusting of UVias light illumination power and pH value of the solution.Consequently,the experiment showed that UVies used as the light source resulted in excellent ARG degradation efficiency,far better than UV254 light source,the degradation rate could reach 97.4%after 20 minutes of illumination,and increasing light power can further upgrade ARG degradation rate,besides,adjusting pH of the waste-water solution to acid can enhance the degradation rate of ARG as well,in the contrary,alkaline condition would cause inhibitory effects.Accordingly,when the pH values adjusted to 3.0,6.7,9.0,11.0 the reaction kinetic constants were equivalent to 0.261,0.174,0.151 and 0.093 min^(-1),respectively,and the kinetics of degradation reaction conformed to the quasi first order kinetic model(R^(2)>0.990).The free radical capture testing showed that the active species·OH and^(1)O_(2)produced in UVias light contributed greatly to the ARG degradation,while·O_(2)_(-),contributed none.The desk-top EPR(electronic para-magnetic resonance spectrometer)was used for detection of free radicals and the results indicated the presence of·OH and^(1)O_(2),but no·O_(2)_(-)。CO_(3)^(2-)was found,and besides,CI had obvious inhibitory effect on ARG degradation,while effects of NO_(3)and SO_(4)^(2-)had on the degradation process were not distinct.On the other hand,the presence of printing/dyeing auxiliaries,e.g.sodium citrate and sodium dodecyl benzene sulfonate(SDBS)very much hindered the removal of ARG;however,the presence of H_(2)O_(2) could significantly accelerate the degradation of ARG.Furthermore,the result of analysis by use of UV-Vis absorption spectrum revealed that the intensity of absorption peak at 509 nm grew weakening continuously and t

关 键 词：UV_(185) 酸性红G ·OH ^(1)O_(2) 高级氧化 

分 类 号：X703[环境科学与工程—环境工程]