摘要
紫外高级氧化工艺在降解去除水中微量有机污染物方面具有良好的应用前景,已有大量相关基础研究在实验室序批式反应器内完成,然而,在实际工程中采用的过流式反应器中的不同水流形态可能会对反应动力学和工艺效率产生影响。为此,采用过流式UV/H_(2)O_(2)反应器降解水中阿特拉津(ATZ),分别考察了H_(2)O_(2)浓度、反应器内径对ATZ降解效率和工艺经济性的影响,同时评估了稳态假设(SSA)模型在过流式UV/H_(2)O_(2)反应器中应用的可行性。结果表明:过流式反应器中UV/H_(2)O_(2)工艺对ATZ有着良好的去除效果,降解过程基本符合拟一级反应动力学(R^(2)>0.95);虽然反应器内流态并非完全混合,SSA模型仍可准确预测反应器中目标污染物的降解,模拟和实验结果相对偏差绝大多数不超过20%;在考察的H_(2)O_(2)浓度范围内,随着浓度的增加,不同反应器中ATZ的降解速率均逐渐增大,特别在H_(2)O_(2)浓度为0.2 mmol·L^(−1)时,内径为35 mm的反应器中ATZ降解速率常数达到5.8×10^(−2)s^(−1),是单独UV辐照下的4倍以上。由于平均紫外强度的变化,增大反应器内径将导致ATZ基于时间的降解速率常数的降低,但对基于紫外剂量的速率常数影响不大。此外,E_(EO)分析结果表明,增加H_(2)O_(2)浓度和增大反应器内径均可以降低ATZ去除的单位能耗。
UV-based advanced oxidation processes are promising in micropollutant removal from water with abundant relative researches accomplished in batch reactors,while the different flow pattern in practical flowthrough UV reactors may lead to a varied reaction kinetic and process efficiency.In this study,the kinetics of atrazine(ATZ)degradation in flow-through UV/H_(2)O_(2)reactors were investigated,and the impacts of H_(2)O_(2)concentration and internal reactor diameter on ATZ removal efficiency and the process energy efficiency were evaluated.The steady-state assumption(SSA)model was developed to predict the degradation kinetics of atrazine under various experimental conditions,and its accuracy was tested by comparing with experimental data.The results showed that the efficient degradation of ATZ occurred in flow-through UV/H_(2)O_(2)reactors and it followed the pseudo first-order kinetics(R^(2)>0.95).Despite the fact that the flow was not fully mixed,SSA model exhibited good accuracy in predicting the degradation of target pollutant in flow-through reactors with deviations generally less than 20%.Within the investigated concentration range,ATZ degradation rate in different reactors increased with the rising of H_(2)O_(2)concentration,and reached 5.8×10^(−2) s^(−1) in the reactor with an internal diameter of 35 mm when H_(2)O_(2)concentration was 0.2 mmol·L^(−1),which was 4 times as much as that in UV radiation alone.The increasing reactor diameter resulted in a low time-based ATZ degradation rate constant on account of the changes in average fluence rate,while had slight effect on the fluence-based ATZ degradation rate constant.Finally,based on the electrical energy per order(EEO)calculation,the energy efficiency in removing ATZ can be reduced by increasing H_(2)O_(2)concentration and reactor diameter.
作者
詹露梦
李文涛
李梦凯
JENSEN Marina Bergen
张淼
强志民
ZHAN Lumeng;LI Wentao;LI Mengkai;JENSEN Marina Bergen;ZHANG Miao;QIANG Zhimin(Key Laboratory of Drinking Water Science and Technology,Research Center for Eco-Environmental Sciences,China Academy Scienles,Beijing 100085,China;Department of Geosciences and Natural Resource Management China Academy Sciences,University of Copenhagen,Frederiksberg C 1985,Denmark;Sino-Danish College of University of Chinese Academy Sciences,Beijing 100049,China;School of Civil and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2021年第3期982-991,共10页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51908536,51525806)
国家重点研发计划(2018YFE0204103)。
