發(fā)布時間：2018-03-30 21:40

  本文選題：熱水解條件　切入點(diǎn)：重金屬　出處：《武漢理工大學(xué)》2015年碩士論文

【摘要】：隨著水處理設(shè)施的進(jìn)一步普及,污泥產(chǎn)量日益增多,而重金屬作為一種污泥中主要污染物,關(guān)于其有效處理途徑的研究正在受到越來越多的關(guān)注。本文以研究熱水解條件對污泥中重金屬的化學(xué)形態(tài)分布的影響為目的,通過單一改變熱水解溫度或者時間,采用改進(jìn)BCR法作為重金屬不同形態(tài)的浸提方法,選取Cu、Zn為重金屬代表元素對其濃度及穩(wěn)定性影響進(jìn)行研究,尋求最佳的熱水解條件;并比較最佳條件下熱水解前后污泥的絮體和其中微生物細(xì)胞結(jié)構(gòu)、有機(jī)物官能團(tuán)、礦物結(jié)晶度變化及處理前后污泥中Cu、Zn的浸出特性變化,試驗(yàn)所得結(jié)論如下:(1)隨著熱水解溫度的不斷升高,污泥中Cu的濃度由原泥的162.4mg/kg上升至210℃時的193.3mg/kg;Zn的濃度由779.7 mg/kg升至210℃時的975.7mg/kg,均上升20%左右。隨著熱水解時間的變化,污泥中Cu的濃度升至處理90min時的218.4 mg/kg;而Zn的濃度在30min時達(dá)到最大,為975.7mg/kg。(2)當(dāng)以提高污泥中Cu和Zn的穩(wěn)定性為目的時,污泥的最佳熱水解條件為210℃、30min,其中Cu與Zn的穩(wěn)定形態(tài)所占比例分別達(dá)到了83.0%和47.4%,相較于原泥分別增加了11.9%和7.3%。比較210℃、30min熱水解處理前后污泥的SEM、FTIR光譜及XRD圖譜均可在微觀上證明污泥在最佳條件下的熱水解有利于其中重金屬的穩(wěn)定化。(3)210℃,30min熱水解前后的污泥中Cu的浸出率均基本隨著浸提液pH的增加而降低,在pH=12時最低,僅為0.3037%。Zn的浸出率變化規(guī)律與Cu相似,不同的是,Zn的浸出率的最低點(diǎn)出現(xiàn)在浸提液pH=10時,Zn的浸出率為0.4123%-0.7526%。在酸性浸提中浸提相同時間,熱水解污泥中Cu和Zn的浸出率明顯均低于原泥,且Zn的浸出率差異相對較大,在pH=2浸提液中浸提率較原泥減少了5.847%-6.591%。(4)210℃,30min熱水解前后的污泥中Cu和Zn在酸性浸提劑中的浸出率均隨著浸提時間的延長基本呈增加趨勢,其中熱水解污泥在酸性浸提劑中浸提15d后Cu的浸出率保持在1.752%-1.978%,較原泥中2.25%左右的浸出率有所降低;相同情況下,原泥中Zn的浸出率為11.91%-14.31%,熱水解后則為6.706%-7.716%,浸出率降低明顯。而在堿性浸提劑中兩種污泥中Cu和Zn的浸出率隨浸提時間的增加均變化不大。(5)通過線性擬合可得到熱水解前后污泥中Cu、Zn在不同pH浸提液中浸提15d后的浸出率(L)與相應(yīng)酸溶態(tài)占Cu、Zn總量比例(P)的線性關(guān)系式,L=aP+b。
[Abstract]:With the further popularization of water treatment facilities, sludge production is increasing day by day. As a major pollutant in sludge, the research on the effective treatment of heavy metals is getting more and more attention.In order to study the influence of hot water hydrolysis conditions on the chemical speciation distribution of heavy metals in sludge, the improved BCR method was adopted to extract different heavy metals by changing the temperature or time of hot water hydrolysis.The effects of Cu Zn as the representative elements of heavy metals on its concentration and stability were studied in order to find the best conditions of hot water hydrolysis, and to compare the flocs of sludge before and after hot water hydrolysis with the microbial cell structure and organic functional groups.The change of mineral crystallinity and leaching characteristics of Cu ~ (2 +) Zn in sludge before and after treatment. The experimental results are as follows: (1) with the increasing of hot water temperature,The concentration of Cu in sludge increased from 162.4mg/kg of raw sludge to 193.3 mg / kg Zn at 210 鈩，

本文編號：1687750