畜禽养殖废水紫外消毒引发有机砷添加剂转化机制及其强化混凝去除

p-arsanilic acid (p-ASA) and roxarsone (ROX) have been used as the most common veterinary feed additives in China. The excessive use of feed additives will cause the residue of the organic arsenic in the soil and water, therefore can severely affect the surrounding environment and poultry health. This project intends to study the photochemical factors and phototransformation mechanisms of p-ASA and ROX in homogeneous and heterogenous systems during UV disinfection through simulative experiments. The practical samples will be collected from the wastewater. Transformation of organic arsenic species will be verified in the practical water. Ultimately, the combined technology of ultraviolet and enhanced coagulant will be applied to remove the residual arsenic. This project aims to expound the efficiency of organic arsenic transformation in the occurrence of several environmental factors, and reveal its transformation mechanism during the UV disinfection process in both homogeneous and heterogenous systems. The generation of As (III) and As (V) and the changes of toxicity will be evaluated in this system. The findings will be advantageous in predicting the migration of organic arsenic, and provide foundations for risk assessment of the residual organic arsenic. Therefore, this project has some practical significance for assessing the environmental safety and controlling the excessive use of organic arsenic.

阿散酸和洛克沙胂作为最常见的有机砷饲料添加剂在国内广泛用于畜禽养殖业，过度使用会导致大量有机砷残存在养殖场的土壤和水体中，严重影响生态环境和畜禽健康。本项目拟通过实验室模拟研究畜禽养殖废水紫外消毒过程中阿散酸和洛克沙胂在水相和悬浮液中的光化学转化影响因素与机制，选取不同地区畜禽养殖废水作为实际采集样品，考察实际废水紫外消毒过程中有机砷形态转化过程，并采用UV/混凝的联合去除方式进行残留砷的强化去除研究。本项目旨在深刻揭示紫外消毒过程中，养殖场有机砷制剂在水中和悬浮液中发生的反应机制和各种环境因子对As形态转化的影响，阐述转化过程中As(III)和As(V)的生成规律及毒性变化。其研究结果为预测有机砷的迁移规律、评估有机砷在环境中的残留与风险提供依据，对于评价畜禽养殖过程中有机砷添加剂的环境安全性、有机砷添加剂的合理使用及污染控制具有一定的现实意义。

阿散酸和洛克沙胂作为最常见的有机砷饲料添加剂在国内广泛用于畜禽养殖业，过度使用会导致大量有机砷残存在养殖场的土壤和水体中，严重影响生态环境和畜禽健康。本项目通过实验室模拟研究畜禽养殖废水紫外消毒过程中阿散酸和洛克沙胂在水相中的光化学转化影响因素与机制，选取不同地区畜禽养殖废水作为实际采集样品，考察实际废水紫外消毒过程中有机砷形态转化过程。本项目重点研究了六个体系中有机砷的光化学转化过程，研究结果表明：在不同体系中，阿散酸和洛克沙胂均能发生形态转化，产生无机砷（As(III)、As(IV)和As(V)），有氧条件下As(III)和As(IV)还会被氧化为As(V)，同时伴生多种高毒性有机污染物。阿散酸和洛克沙胂光解过程中存在直接/间接光解反应、有氧/无氧等多途径下的多转化机制以及多种自由基的氧化贡献。本项目深刻了揭示紫外消毒过程中，养殖场有机砷制剂在水中发生的反应机制和各种环境因子对As形态转化的影响，阐述转化过程中As(III)和As(V)的生成规律及毒性变化。其研究结果为预测有机砷的迁移规律、评估有机砷在环境中的残留与风险提供依据，对于评价畜禽养殖过程中有机砷添加剂的环境安全性、有机砷添加剂的合理使用及污染控制具有一定的现实意义。