【摘要】：鉈作為一種劇毒且是人體內(nèi)非必需的稀有重金屬元素,其對(duì)生物體乃至環(huán)境都有非常大的危害作用,在自然界中,主要是以較為穩(wěn)定的Tl+形式存在于水體中,目前,僅在我國(guó)報(bào)道有獨(dú)立的鉈礦床存在。鉈在生活中的應(yīng)用非常廣泛,但其毒性卻不容小覷。共沉絮凝法是通過(guò)加入一些化學(xué)藥劑而達(dá)到去除廢水中雜質(zhì)的目的;吸附法則是利用具有吸附效果的吸附劑將廢水中的雜質(zhì)由液相轉(zhuǎn)移至固相;離子交換主要是通過(guò)雜質(zhì)離子與表面帶有相同電荷的離子交換樹(shù)脂進(jìn)行離子交換而達(dá)到凈化的目的。本文主要是分別采用共沉絮凝法,吸附法,離子交換三種方法去除廢水中的鉈。共沉絮凝法是以湖南省某鋼鐵冶金燒結(jié)煙氣脫硫含鉈廢水為研究對(duì)象,研究了Na2S,Na2CO3,聚丙烯酰胺(PAM)對(duì)廢水中鉈的去除,且結(jié)合廢水中鉈的去除率及經(jīng)濟(jì)成本確定最優(yōu)藥劑配比;吸附法則是以模擬含鉈廢水為研究對(duì)象,通過(guò)一系列的吸附實(shí)驗(yàn),探討了鉈(Ⅰ)在粉末活性炭上的吸附行為和主要影響因素,并且對(duì)吸附動(dòng)力學(xué),吸附熱力學(xué)進(jìn)行了初步研究。離子交換法亦是以模擬含鉈廢水為研究對(duì)象,對(duì)其主要影響因素進(jìn)行了考察,找出了最佳處理?xiàng)l件。研究結(jié)果如下:采用共沉絮凝法處理1 L鋼鐵冶金燒結(jié)煙氣脫硫含鉈廢水的藥劑最優(yōu)配比為3 mL質(zhì)量分?jǐn)?shù)為10%的Na2S溶液,5 g無(wú)水Na2CO3固體0.5 mL質(zhì)量分?jǐn)?shù)為1%的絮凝劑PAM,絮凝劑可加速絮狀物的沉降;采用活性炭吸附去除廢水中的鉈宜在堿性條件下進(jìn)行,吸附平衡時(shí)間為2 h,吸附動(dòng)力學(xué)研究結(jié)果表明活性炭吸附鉈的行為更符合Lagergren偽二級(jí)動(dòng)力學(xué)模型,等溫吸附線研究表明Freundlich模型能比Langmuir模型更好地描述活性炭吸附鉈的行為,吸附熱力學(xué)的研究結(jié)果表明活性炭吸附鉈是自發(fā)進(jìn)行的反應(yīng),該過(guò)程放熱,因此,宜在低溫條件下進(jìn)行吸附實(shí)驗(yàn),溶液中共存離子的存在會(huì)嚴(yán)重影響活性炭對(duì)廢水中鉈的吸附,且去除率隨著共存離子濃度的增加而大幅度降低;采用陽(yáng)離子交換樹(shù)脂去除廢水中的鉈宜在偏堿性條件下進(jìn)行,平衡時(shí)間為1.5 h,當(dāng)廢水中初始鉈離子濃度低于1 mg/L時(shí),使用陽(yáng)離子交換樹(shù)脂可將廢水中的鉈全部去除,溶液中的共存離子對(duì)離子交換樹(shù)脂除鉈的影響較大,另外,離子交換樹(shù)脂除鉈是一個(gè)吸熱反應(yīng),因此,適當(dāng)升溫有利于陽(yáng)離子交換樹(shù)脂對(duì)鉈的處理。經(jīng)濟(jì)性分析研究結(jié)果表明,采用共沉絮凝法不僅處理效果優(yōu)于吸附法及離子交換法,且所需成本遠(yuǎn)遠(yuǎn)小于吸附法及離子交換法。
[Abstract]:Thallium, as a highly toxic and non-essential heavy metal element in human body, has great harm to organism and environment. In nature, thallium mainly exists in water body in the form of TL. Independent thallium deposits have been reported only in China. Thallium is widely used in life, but its toxicity is not to be underestimated. The method of co-settling flocculation is to remove impurities in wastewater by adding some chemical agents, and the adsorption rule is to transfer impurities from liquid phase to solid phase by using adsorbent with adsorption effect. Ion exchange is achieved by ion exchange between impurity ions and ion exchange resins with the same charge on the surface. In this paper, the removal of thallium in waste water by co-settling flocculation method, adsorption method and ion exchange method respectively. The coprecipitation flocculation method was used to study the removal of thallium from iron and steel metallurgical flue gas desulphurization containing thallium wastewater in Hunan province. The removal of thallium from wastewater by Na _ 2S _ 2CO _ 3 and polyacrylamide (PAM) was studied, and the optimum proportion was determined by combining the removal rate and economic cost of thallium in wastewater. A series of experiments were carried out to study the adsorption behavior of thallium (鈪，

本文編號(hào)：2148332