运用超声和高锰酸钾-超声(KMn04-超声)工艺协同降解饮用水中的17β-雌二醇(E2),比较了2种工艺去除E2的效果及高锰酸钾投加量、溶液pH值、水中常见阴阳离子和天然有机物(NOM)等因素对去除E2的影响,并利用叔丁醇验证了E2降解过程中羟基自由基(·OH)的作用.结果表明:超声对E2的降解效果不佳,反应60min去除率仅为21.1%,KMnO。-超声可明显提高目标物的去除率至97.8%,KMnO4的协同作用随反应时间呈现先增强后减弱的趋势.酸碱性对超声和KMnO;-超声降解E2的效果存在影响,且影响规律不同,超声:I=艺的最佳pH值条件为强碱性,KMnO。-超声则在强酸性条件下具有最优去除效果;NaCl的存在能促进2种工艺对E2的去除效果;阴离子型表面活性剂十二烷基磺酸钠(SDBS)对2种工艺去除E2有促进作用;NOM可促进超声对E2的降解,对KMnO4-超声则有先促进后抑制的效果;叔丁醇对超声和KMnO。-超声均具有抑制作用,说明在超声工艺中·OH对E2的降解具有重要作用.相比较而言,高锰酸钾-超声协同降解E2具有降解效率高、节省处理时间和缩小工艺体积等优点.
Processes of ultrasound and KMnO4/ultrasound were adopted to remove 17β-estradiot (E2) from drinking water. Two techniques were compared in term of pollution control effect, and several influencing factors such as KMnO, dosage, pH, common cation/anion and natural organic matter (NOM) were discussed. The hydroxyl radicals scavenger (tert-butyl alcohol) was used to figure out the main action of hydroxyl radicals in degradation of E2. Results show that ultrasound is ineffective in destruction of E2 with removal ratio of 21.1% after 60 min contact, however, KMnO4/ultrasound can enhance the ratio to 97.8% under the same condition. Synergistic effects of KMnO4 follows a trend of first strengthen and then weaken. As to influencing factors, acid-alkaline property has effect on E2 destruction and plays differentroles in the ultrasound and KMnO4/ultrasound processes, respectively. Optimal pH condition for the ultrasound process is strong alkaline, while strong acid for the KMnO4/ultrasound process. Presence of NaCI or anionic surfactant sodium dodecyl benzene sulfonate the can promote the degradation of E2 in these two investigated processes. NOM accelerates the degradation of E2 by ultrasound, while to the KMnO4/ ultrasound process, the effect is first promotion and then inhibition. Tert-butyl alcohol's inhibition in removal of E2 by ultrasound and KMnO4/ultrasound indicates that the hydroxyl radicals play important role in the E2 degradation. The KMnO4/ultrasound process has the advantages of high degradation efficiency, short treating time and small size of process.