本文選題：制革污泥 + 抗壞血酸　； 參考：《廣西大學》2017年碩士論文

【摘要】：本文以廣西賓陽縣某制革廠的剩余制革污泥為研究對象,測定了制革污泥的基本性質(含水率、有機質含量、pH值、總鉻及六價鉻含量),采用Tessier及BCR兩種形態(tài)提取方法研究了制革污泥中鉻的形態(tài)分布,選用抗壞血酸為還原劑研究了模擬制革污泥中六價鉻的還原條件,并采用氧化焙燒-水浸實驗回收制革污泥中的鉻。本文實驗結果表明:(1)采用Tessier及BCR連續(xù)提取法研究污泥樣品中鉻的形態(tài)分布,Tessier結果表明制革污泥中重金屬鉻主要以鐵錳氧化物結合態(tài)(87%～88%)存在,BCR結果表明制革污泥中重金屬鉻主要以可氧化態(tài)(97%)存在,兩種方法得到的其它形態(tài)鉻的比例均較低。(2)選用抗壞血酸還原模擬制革污泥中的六價鉻,結合單因素實驗、正交實驗及經(jīng)濟因素,得出六價鉻還原的最佳實驗條件為抗壞血酸投加量為理論用量(根據(jù)化學反應方程式計算)的1.5倍,pH為2.0,反應時間4 h,反應溫度35℃。在此條件下,六價鉻的還原率為82.2%。(3)通過氧化焙燒-水浸實驗回收制革污泥中的鉻,實驗結果表明影響浸出效果最主要的因素是焙燒溫度,然后依次是水浸時間、Na2CO3投加量和焙燒時間。最佳操作條件是Na2CO3投加量1.0g/g,焙燒溫度600℃,焙燒時間1.5h,水浸時間1.2h。在此條件下,浸出液中六價鉻占污泥總鉻百分比為95.5%。浸出液中的六價鉻通過抗壞血酸還原、調節(jié)pH產生沉淀、煅燒沉淀等一系列實驗過程,以Cr2O3的形式回收鉻,回收率達到90%。
[Abstract]:In this paper, the basic properties (moisture content, organic matter content and pH value of tannery sludge) in a tannery in Binyang County, Guangxi, were determined. The speciation distribution of chromium in tannery sludge was studied by Tessier and BCR, and the reduction conditions of hexavalent chromium in simulated tannery sludge were studied by using ascorbic acid as reducing agent. Oxidation roasting-water leaching experiment was used to recover chromium from tannery sludge. The experimental results show that Tessier and BCR continuous extraction methods are used to study the speciation distribution of chromium in the sludge samples. The results show that the heavy metal chromium in tannery sludge is mainly composed of iron and manganese oxide bound iron and manganese oxide. The results show that there is a BCRs in tannery sludge. The heavy metal chromium mainly exists in the oxidizable state. The ratio of other forms of chromium obtained by the two methods is lower. (2) ascorbic acid is used to reduce hexavalent chromium in simulated tannery sludge, combined with single factor experiment, orthogonal experiment and economic factors. The optimum experimental conditions of hexavalent chromium reduction are as follows: the dosage of ascorbic acid is 1.5 times of the amount of ascorbic acid (calculated according to the chemical reaction equation), the pH of ascorbic acid is 2.0, the reaction time is 4 h, and the reaction temperature is 35 鈩，

本文編號：1786419