摘要
阿散酸(p-arsanilic acid,ASA)是一种重要的有机砷化合物,较无机砷更加难以去除,目前关于去除水中ASA研究少有报道.本研究主要评价了TiO_2光催化剂(P25)对ASA的去除效果,考察了P25投量、pH和光照强度对其光催化氧化ASA的影响,探究了ASA光降解产物和主要机制.结果表明,在P25催化作用下,模拟自然光可氧化降解ASA为As(V),最终通过P25对As(V)的吸附作用将水中砷有效去除.当ASA初始浓度为2 mg·L^(-1),P25投量为1 g·L^(-1)时,光催化氧化-吸附0.5 h后,水中剩余砷的浓度约为0.34 mg·L^(-1).酸性条件下ASA的去除率远远高于碱性条件,最佳光照强度为68.5 mW·cm^(-2).P25光催化氧化ASA过程中羟基自由基起到了主要作用.
The p-arsanilic acid（ASA） is an important organoarsenical compound and its removal is more difficult compared to inorganic arsenic,however,little attention has been paid to the removal of ASA in aqueous environment.The influence of P25 on the adsorption of ASA,effect of P25 dosage,pH and illumination intensity on the photo-catalysis,the production analysis and main mechanism of photo-degradation were investigated in this study.The results showed that in the P25 catalysis process,simulated natural light could degrade ASA into As（V） by oxidation.The total As was reduced to about 0.34 mg L^-1 within 0.5 h under the following condition：the initial concentration of ASA was 2 mg L^-1 and the dosage of TiO2 was 1 g L^-1.The result showed that the removal rate of ASA in acidic conditions was much higher than that in alkaline conditions.The optimal strength of light was 68.5 mW cm-（-2）.Hydroxide radical played a major role in photocatalytic oxidation of ASA by P25.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2016年第1期193-197,共5页
Environmental Science
基金
国家自然科学基金项目(51378490)
国家高技术研究发展计划(863)项目(2012AA062604)
关键词
二氧化钛
阿散酸
光催化
吸附
羟基自由基
TiO_2
p-arsanilic acid（ASA）
photocatalytic reaction
adsorption
hydroxide radical
