【摘要】：重金屬釩污染已經(jīng)嚴(yán)重威脅到了當(dāng)下環(huán)境以及生物系的健康發(fā)展,未經(jīng)達(dá)標(biāo)處理而排放的含釩廢水,會(huì)對(duì)水體、土壤、植被乃至整個(gè)生態(tài)系統(tǒng)造成嚴(yán)重的影響。此外,我國(guó)的鉻鹽生產(chǎn)約占世界總產(chǎn)量的35%,是鉻鹽生產(chǎn)大國(guó),在以綠色環(huán)保的無鈣焙燒工藝為主導(dǎo)的形勢(shì)下,鉻酸鹽浸出液中的釩濃度常高達(dá)560 mg·L~(-1)(以V~(5+)計(jì)),為滿足后續(xù)鉻鹽產(chǎn)品的制備需求,必須進(jìn)行除釩處理。針對(duì)溶液中釩離子的去除,研究出一種高效便捷的分離方法是當(dāng)下勢(shì)在必行的一項(xiàng)課題。本文首先以K_2CrO_4為原料,經(jīng)氫氣還原制備出了γ-CrOOH;以CrCl_3·6H_2O作為鉻源,通過添加強(qiáng)堿制備出了介孔Cr(OH)_3。隨后,細(xì)致研究了兩種材料對(duì)溶液中五價(jià)釩離子的靜態(tài)與動(dòng)態(tài)吸附性能。最后,結(jié)合實(shí)際水質(zhì)情況配制了模擬溶液,初步探討了兩種材料實(shí)際應(yīng)用的可行性。主要?jiǎng)?chuàng)新性結(jié)果如下:1)系統(tǒng)研究并確定了γ-CrOOH對(duì)V~(5+)的最佳吸附條件:溶液pH為2.0、吸附劑用量為60:1(nCr:nV)、適宜的吸附溫度為30℃。在此條件下,經(jīng)過10.0 h的吸附,釩離子出水濃度可由300 mg·L~(-1)降低至0.75 mg·L~(-1)。在有常見離子的存在下,γ-CrOOH的除釩率依然維持在97%以上;釩鉻共存模擬液(150~250 g·L~(-1)的Na2Cr2O7·2H_2O中V~(5+)的濃度為500 mg·L~(-1)),除釩后釩離子濃度可降低至45 mg·L~(-1)以下。γ-CrOOH可實(shí)現(xiàn)很好的解吸并且解吸液中的釩離子可實(shí)現(xiàn)富集與回收再利用。2)制得的Cr(OH)_3其比表面積高達(dá)312.70 m2·g-1、孔體積為0.48 cm3·g-1。該吸附劑在溶液pH處于2.0~9.0的范圍內(nèi),均可表現(xiàn)出較高的除釩率;經(jīng)過14.0 h吸附,釩離子出水濃度可由500 mg·L~(-1)降低至0.81 mg·L~(-1)。該吸附過程同樣符合擬二級(jí)動(dòng)力學(xué)方程與Langmuir等溫吸附方程。當(dāng)溶液中存在常見的陰離子與陽離子時(shí),Cr(OH)_3的除釩效率仍高達(dá)99.6%以上;釩鉻共存模擬液中可有效地將釩離子完全去除。以鈉化焙燒-水浸-酸性銨鹽沉釩工藝所產(chǎn)生的含釩廢水作為參考,配制出的具有相同組分的含釩廢水模擬液,經(jīng)靜態(tài)吸附處理,溶液中釩離子的去除率可達(dá)99.88%。Cr(OH)_3同樣可實(shí)現(xiàn)很好的解吸。3)對(duì)γ-CrOOH與Cr(OH)_3進(jìn)行裝柱處理,以單床降流式對(duì)其動(dòng)態(tài)吸附性能進(jìn)行了研究。結(jié)果表明,較慢的流速、較高的裝填高度與低濃度的釩溶液,能夠適當(dāng)?shù)奶岣邉?dòng)態(tài)吸附效率。γ-CrOOH與Cr(OH)_3作為新型的介孔吸附材料對(duì)V~(5+)具有很好的去除能力,同時(shí)具有操作簡(jiǎn)便,性能優(yōu)良的特性,為水處理領(lǐng)域的進(jìn)一步研究提供了很好的參考價(jià)值。
[Abstract]:Vanadium pollution has seriously threatened the current environment and the healthy development of biological systems. Vanadium wastewater discharged without standard treatment will have a serious impact on water, soil, vegetation and even the whole ecosystem. In addition, the production of chromium salt in China accounts for about 35% of the world's total output. It is a big country in the production of chromium salt. Under the situation of taking the green environment free calcium roasting process as the leading factor, The vanadium concentration in chromate leachate is as high as 560 mg L ~ (-1) (V ~ (5). In order to meet the needs of the preparation of subsequent chromate products, vanadium removal must be carried out. For vanadium ion removal in solution, it is imperative to develop an efficient and convenient separation method. In this paper, firstly, 緯-CrOOH; was prepared by hydrogen reduction using K_2CrO_4 as raw material and CrCl_3 6H_2O as chromium source. Mesoporous Cr (OH) _ 3 was prepared by adding strong alkali. Then, the static and dynamic adsorption properties of the two materials for pentavalent vanadium ions in solution were studied in detail. Finally, the simulated solution was prepared in combination with the actual water quality, and the feasibility of the two materials in practical application was preliminarily discussed. The main innovative results are as follows: 1) the optimal adsorption conditions for V ~ (5) by 緯-CrOOH were studied and determined: pH of solution was 2.0, amount of adsorbent was 60:1 (nCr:nV), and the optimum adsorption temperature was 30 鈩，

本文編號(hào)：2311230