膜-悬浮光催化降解反应器中催化剂活性及其影响因素分析

考察了膜 悬浮光催化降解反应器小试系统在处理自配废水的连续运行中催化剂活性的变化 .试验发现 ,经两周的连续运行 ,催化剂活性有明显降低 ,降为原催化剂活性的 1 4 % .分析引起催化剂活性降低的可能原因有 :催化剂颗粒的聚集、有机污染物和无机垢体在催化剂表面的附着 .采用超声波粉碎、次氯酸钠碱洗和盐酸酸洗的方法来恢复催化剂活性 .结果表明 ,采用 1 0 %的盐酸清洗可使催化剂活性恢复到初始值的 6 4 %左右 ,效果最明显 .推测由于水中硬度在催化剂表面形成的CaCO3沉淀是导致催化剂活性降低的最主要因素 .

ANALYSIS OF CATALYST DEACTIVATION AND INFLUENCING FACTORS IN MEMBRANE-PHOTOCATALYTIC DEGRADATION SLURRY REACTOR

In the present study,activity change of catalyst in a membrane-photocatalytic degradation slurry reactor was investigated.After run for two weeks in treating artificial wastewater,the catalyst activity declined noticeably,only 14% of the initial value.Three possible reasons causing catalyst deactivation were presumed:catalyst agglomeration,organic fouling and inorganic precipitation on the catalyst surface.Correspondingly three recovering methods were applied to restore the deactiva- ted catalysts:ultrasonic comminution,basic chemical cleaning with hypochlorite and acidic rinsing with HCl.Acidic rinsing with HCl was found to be the most effective,restoring the catalyst activity up to around 64% of the initial value.This suggested that CaCO 3 scaling on the catalyst' surface caused by water hardness was the overwhelming reason for catalyst deactivation.