多元金属氧化物对水中苯胂酸类污染物的吸附性能及机理

Adsorption performance and mechanism of phenylarsonic acid in water onto multi-component metal oxides

砷污染一直是全球关注的环境问题。以典型苯胂酸—阿散酸(p-ASA)为目标污染物,通过水热法制备了锌-铁-锆复合金属氧化物(ZnFeZrO_(x))吸附剂,探究了ZnFeZrO_(x)对p-ASA的吸附行为和吸附机理。结果表明:在pH=4,吸附温度为60℃,ZnFeZrO_(x)投加量为2.2 g·L^(-1),p-ASA初始质量浓度为50 mg·L^(-1)时,ZnFeZrO_(x)对pASA的去除率可达95.15%。该吸附过程符合Freundlich等温吸附模型和准二级动力学模型,最大吸附容量为595.23 mg·g^(-1)。而在吸附实际废水的实验中,ZnFeZrO_(x)对牲畜养殖废水中p-ASA的去除率仍保持在较高的水平(84.92%)。表征结果表明,ZnFeZrOx在吸附过程中具有良好的化学稳定性,Fe-OH为主要吸附活性位点,ZnO和Zr-O起到一定作用。ZnFeZrO_(x)具有良好的再生性能,重复使用3次后,对p-ASA的去除率仍能达到70%以上。

Arsenic contamination has been a global environmental issue.In this study,the typical phenylarsonic acid,named p-ASA,was selected as the target pollutant to investigated the adsorption behaviour and mechanism of zinc-iron-zirconium metallic oxide(ZnFeZrO_(x))prepared by hydrothermal method.The results indicated that 95.15%of p-ASA was absorbed on the ZnFeZrO_(x) under the optimal conditions:pH4,60℃,ZnFeZrO_(x) dosage of 2.2 g·L^(−1),and initial p-ASA concentration of 50 mg·L^(−1).The adsorption process was in accordance with the Freundlich isothermal adsorption model and quasi-secondary kinetic model,and the maximum adsorption capacity was 595.23 mg·g^(−1).In the experiment of adsorption of livestock breeding wastewater,the removal rate maintained at a high level(84.92%).In addition,ZnFeZrO_(x) showed a good chemical stability during p-ASA adsorption,Fe-OH was the main adsorption active site,and Zn-O and Zr-O played a certain role.After three times of recycle,the removal efficiency of p-ASA still reached higher than 70%,manifesting that ZnFeZrO_(x) had a good regeneration performance.