本文選題：氯代烴 + 曝氣吹脫�。� 參考：《中國地質(zhì)大學(北京)》2017年碩士論文

【摘要】：地下水中的氯代烴種類多、危害大,對地下水安全和人類健康存在極大隱患。本文以地下水中含量相對較多的四種氯代烴,即四氯化碳、三氯甲烷、三氯乙烯和四氯乙烯為目標污染物,研究如何用曝氣吹脫技術(shù)快速去除地下水中的氯代烴污染物。本文研究了影響曝氣吹脫去除氯代烴的主要影響因素,包括單位面積曝氣量,氯代烴初始濃度和溫度,并探究了氯代烴共存對去除率的影響。最終建立曝氣吹脫去除氯代烴的數(shù)學模型,通過模型分別對氣水比與氯代烷烴和氯代烯烴的去除效果進行預(yù)測,并初步探究了分子連接指數(shù)與曝氣吹脫速率的關(guān)系,以便為該技術(shù)的實際應(yīng)用提供參考,具體結(jié)論如下:(1)通過本文的實驗探究,表明曝氣吹脫技術(shù)可以快速有效的去除地下水中的氯代烴污染物,單位面積曝氣量越大,氯代烴初始濃度越小,溫度越高,達到排放標準需要的時間越短。但是單位面積曝氣量增大能耗也會相應(yīng)增大,因此,用曝氣吹脫技術(shù)去除5 mg/L的氯代烴最佳條件為單位面積曝氣量在0.421~0.631m3/(m2·min)之間,溫度高于20℃。(2)同樣的實驗條件下,四氯化碳、三氯甲烷、三氯乙烯和四氯乙烯的去除速率關(guān)系為四氯化碳四氯乙烯三氯乙烯三氯甲烷。多種氯代烴共存可以提高每種氯代烴的去除率。(3)曝氣吹脫系統(tǒng)模型可以表示為C/C_0=exp(-G·q),吹脫系數(shù)G與亨利常數(shù)H有關(guān),q為氣水比。利用該模型對氯代烷烴和氯代烯烴在不同氣水比下的吹脫效果進行了模擬預(yù)測,水溫為20℃時,所測氯代烴去除率達50%、70%和90%所需要的氣水比分別為:四氯化碳6.48、11.25、21.52,三氯甲烷17.33、30.10、57.56,三氯乙烯13.59、23.61、45.15,四氯乙烯9.90、17.20、32.89�？梢来巫鳛槠貧獯得摷夹g(shù)去除氯代烴污染地下水的曝氣量控制依據(jù)。(4)在溫度25℃,初始濃度5 mg/L,單位面積曝氣量為0.526 m3/(m2·min)的條件下,擬一級反應(yīng)速率常數(shù)k與零級分子連接指數(shù)0χ相關(guān)性較好,相關(guān)方程為k=0.1457×0χ-0.4066,相關(guān)指數(shù)R~2=0.8401。
[Abstract]:There are many kinds of chlorinated hydrocarbons in groundwater, which are harmful to groundwater safety and human health. In this paper, four kinds of chlorinated hydrocarbons in groundwater, namely carbon tetrachloride, trichloromethane, trichloroethylene and tetrachloroethylene, were used as target pollutants. In this paper, the main factors affecting the removal of chlorinated hydrocarbons by aeration blowing are studied, including aeration amount per unit area, initial concentration and temperature of chlorinated hydrocarbons, and the influence of the coexistence of chlorinated hydrocarbons on the removal rate is discussed. Finally, a mathematical model for removal of chlorinated hydrocarbons by aeration blowing was established. The effects of gas-water ratio on removal of chlorinated alkanes and chlorinated alkenes were predicted by the model, and the relationship between molecular linkage index and aeration blowing rate was preliminarily explored. In order to provide a reference for the practical application of this technology, the concrete conclusion is as follows: 1) through the experimental research in this paper, it is shown that aeration technology can quickly and effectively remove chlorinated hydrocarbon pollutants from groundwater, and the greater the aeration amount per unit area, the greater the amount of aeration per unit area. The lower the initial concentration of chlorinated hydrocarbons, the higher the temperature and the shorter the time required to meet the emission standard. However, the energy consumption per unit area aeration will increase accordingly. Therefore, the best conditions for removal of chlorinated hydrocarbons by aeration blowing technology for 5 mg/L are as follows: the aeration rate per unit area is between 0.421~0.631m3/(m2 and 0.421~0.631m3/(m2, and the temperature is higher than 20 鈩，

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