【摘要】：作為一種重要化工原料,氯酚類(lèi)物質(zhì)已被廣泛應(yīng)用于日常生產(chǎn)和生活,由此產(chǎn)生的環(huán)境問(wèn)題也日益嚴(yán)重。本文以對(duì)氯苯酚(4-CP)作為目標(biāo)污染物,采用零價(jià)鐵活化過(guò)硫酸鉀高級(jí)氧化技術(shù)處理對(duì)氯苯酚模擬廢水,并對(duì)4-CP去除效率的主要影響因素及體系的降解機(jī)理進(jìn)行了研究。本文考察了反應(yīng)溫度、初始pH、目標(biāo)污染物濃度、零價(jià)鐵投加量等因素對(duì)體系去除4-CP的影響。結(jié)果表明,零價(jià)鐵/過(guò)硫酸鉀體系能夠有效去除廢水中對(duì)氯苯酚且最佳反應(yīng)條件為:反應(yīng)溫度為30℃、體系初始pH值為5、目標(biāo)污染物初始濃度為20mg/L、零價(jià)鐵投加量為0.3g/L、過(guò)硫酸鉀濃度為1.6mmol/L。最佳實(shí)驗(yàn)條件下,60分鐘時(shí)4-CP去除率可達(dá)90%以上。進(jìn)一步的實(shí)驗(yàn)表明,過(guò)硫酸鉀的分批投加也可以提高4-CP去除率。通過(guò)降解動(dòng)力學(xué)模擬可知,對(duì)氯苯酚的降解反應(yīng)符合準(zhǔn)一級(jí)反應(yīng)動(dòng)力學(xué)。過(guò)硫酸鉀/零價(jià)鐵體系在降解過(guò)程中的特性研究表明,溶液的pH值會(huì)隨著反應(yīng)的進(jìn)行而逐漸降低,證明體系中有酸性物質(zhì)產(chǎn)生。二價(jià)鐵離子濃度變化與4-CP去除率關(guān)系顯示,亞鐵離子濃度直接決定4-CP去除率的高低。由不同體系的對(duì)照實(shí)驗(yàn)可知,單獨(dú)零價(jià)鐵體系和單獨(dú)過(guò)硫酸鉀體系對(duì)4-CP的去除率較低,表明4-CP的降解是體系聯(lián)合作用的結(jié)果。自由基清除劑實(shí)驗(yàn)顯示,添加甲醇和叔丁醇后,體系4-CP去除率分別降低了70%和30%。結(jié)果表明,體系中生成了硫酸根自由基和羥基自由基,而且硫酸根自由基對(duì)4-CP的降解起著主要作用。羥基自由基產(chǎn)生量檢測(cè)的實(shí)驗(yàn)數(shù)據(jù)進(jìn)一步證實(shí)了這一結(jié)論。TOC測(cè)定結(jié)果顯示,體系的礦化率遠(yuǎn)遠(yuǎn)低于同時(shí)刻4-CP的去除率,礦化過(guò)程進(jìn)行得比較緩慢。離子色譜法捕捉到體系中氯離子濃度逐漸增加,表明體系中發(fā)生了脫氯反應(yīng)。結(jié)合之前分析結(jié)果,4-CP的降解過(guò)程大致可推測(cè)如下:首先4-CP發(fā)生脫氯反應(yīng)和氧化反應(yīng)生成中間產(chǎn)物對(duì)苯二酚和對(duì)苯醌,然后中間產(chǎn)物被硫酸根自由基攻擊,發(fā)生開(kāi)環(huán)氧化生成小分子酸,最后轉(zhuǎn)化為二氧化碳和水而除去。
[Abstract]:As an important chemical raw material, chlorophenols have been widely used in daily production and daily life, resulting in increasingly serious environmental problems. In this paper, p-chlorophenol (4-CP) was used as the target pollutant to treat the simulated wastewater of p-chlorophenol by using zero-valent iron activated potassium persulfate advanced oxidation technology. The main factors affecting the removal efficiency of 4-CP and the degradation mechanism of the system were studied. In this paper, the effects of reaction temperature, initial pH, concentration and zero valent iron dosage on the removal of 4-CP from the system were investigated. The results show that the zero-valent iron / potassium persulfate system can effectively remove p-chlorophenol from wastewater. The optimum reaction conditions are as follows: reaction temperature is 30 鈩，

本文編號(hào)：2212642