本文選題：活性污泥　切入點：煤生物降解　出處：《天津理工大學(xué)》2017年碩士論文

【摘要】：我國是煤炭儲量和消耗量大國。目前,煤炭最主要的利用方式是燃燒。煤炭的直接燃燒會造成嚴重的環(huán)境污染,使霧霾天氣增多。因此,如何實現(xiàn)煤炭的清潔轉(zhuǎn)化,是我國踐行人與自然和諧共生理念必須面對的課題。本研究的主要目的是從活性污泥中篩選出能夠降解煤的微生物,為煤生物降解在菌種選育方面提供新的方向,為煤的生物降解利用的進一步研究提供理論基礎(chǔ)。首先,將富集培養(yǎng)之后的污泥上清液轉(zhuǎn)接至含有50m L無機鹽培養(yǎng)液和0.5g煤的錐形瓶中培養(yǎng)。觀察發(fā)現(xiàn),實驗組瓶中有氣泡浮在液面,而對照組中沒有;實驗組煤樣的電鏡圖和紅外光譜圖表明,煤樣表面空隙增大,煤樣中分子結(jié)構(gòu)發(fā)生變化;實驗組上清液元素分析結(jié)果顯示,上清液中Ca、Mg和P的含量有所減少,Zn的含量有所增加。以上變化表明活性污泥中存在能夠降解煤的微生物,證實從活性污泥中篩選能夠降解煤菌種的可行性。其次,利用控制變量的方法對泥碳比進行優(yōu)化;利用Minitab設(shè)計中心復(fù)合實驗對無機鹽培養(yǎng)液的成分進行優(yōu)化;利用正交實驗(三因素三水平)對培養(yǎng)溫度、煤樣預(yù)處理方法和pH進行優(yōu)化。最終得到微生物降解煤的最佳培養(yǎng)方案,即泥3g、煤樣0.5g、無機鹽培養(yǎng)液50mL、未經(jīng)處理煤樣、培養(yǎng)溫度35℃和pH設(shè)為8。其中無機鹽培養(yǎng)液的成分為:磷酸二氫鉀的濃度為1.1g/L,氯化鈣的濃度為1.1g/L,硫硫酸鐵的濃度為0.4/L,酸鎂的濃度為0.1g/L,氯化鈉的濃度為0.5g/L,硝酸銨的濃度為5g/L,。再次,利用Z字劃線方法從活性污泥中分離菌種,將得到的5種菌種回接至無機鹽培養(yǎng)液為50mL和煤樣為0.5g的錐形瓶中恒溫培養(yǎng)。上清液元素分析結(jié)果表明接入菌種Z1的上清液中Ca、Mg、P和Zn元素含量較對照組有所變化,接入其余菌種的上清液元素含量變化不大;煤樣紅外光譜分析結(jié)果表明,經(jīng)過菌種Z1、Z2和Z3作用后的煤樣中芳環(huán)結(jié)構(gòu)和含氧官能團均有所變化,而接入其余菌種的煤樣分子結(jié)構(gòu)變化微小;菌種Z1、Z2和Z3作用后的煤樣電鏡圖顯示,其煤樣松散程度增加。因此,最終篩選出能夠降解煤的菌種Z1、Z2和Z3。菌種Z1的降解率最大。利用水浸片和革蘭氏染色法初步分析得到:菌種Z1為放線,菌種Z2為毛霉菌,菌種Z3為酵母菌。最后,研究菌種Z1、Z2和Z3對煤的降解效果。利用ICP-OES等離子光譜儀分析液態(tài)降解產(chǎn)物,結(jié)果表明Ca元素、Mg元素和P元素的含量減少,Zn元素含量增加,這說明在微生物降解煤的過程中,培養(yǎng)液中部分元素被利用,煤中部分元素析出;利用紅外光譜分析固態(tài)降解產(chǎn)物,結(jié)果表明煤樣中芳環(huán)結(jié)構(gòu)相對增多,含氧官能團和C≡C鍵相對減少,這說明產(chǎn)物中有芳環(huán)結(jié)構(gòu)生成,降解過程中有氧化水解作用發(fā)生。降解率的計算結(jié)果顯示,多種菌種聯(lián)合作用的降解效果好于單一菌種。其中菌種Z1、菌種Z2和菌種Z3共同對煤樣進行降解的降解率最好。
[Abstract]:China is a big country in coal reserves and consumption. At present, the most important way to use coal is combustion. Direct combustion of coal will cause serious environmental pollution and increase haze weather. Therefore, how to realize clean conversion of coal, The main purpose of this study is to screen out the microorganisms that can degrade coal from activated sludge and to provide a new direction for the breeding of coal biodegradation. It provides a theoretical basis for further study on the biodegradation and utilization of coal. Firstly, the sludge supernatant after enrichment and culture is transferred to a conical bottle containing 50 mL inorganic salt and 0.5 g coal. There were bubbles floating in the bottle in the experimental group, but not in the control group. The electron microscope and infrared spectra of the coal sample in the experimental group showed that the void on the surface of the coal sample increased and the molecular structure of the coal sample changed; the element analysis of the supernatant of the experimental group showed that, The contents of Ca, mg and P in the supernatant decreased and the content of Zn increased. The above changes indicated that there were microorganisms capable of degrading coal in the activated sludge, which proved the feasibility of screening the bacteria that could degrade the coal from the activated sludge. The sludge / carbon ratio was optimized by the method of controlling variables, the composition of inorganic salt culture solution was optimized by Minitab design center compound experiment, and the culture temperature was optimized by orthogonal experiment (three factors and three levels). The pretreatment method and pH of coal sample were optimized. Finally, the optimum culture scheme of microbial degradation of coal was obtained, that is, mud 3g, coal sample 0.5g, inorganic salt culture solution 50mL, untreated coal sample, untreated coal sample, untreated coal sample, untreated coal sample, untreated coal sample. The culture temperature is 35 鈩，

本文編號：1681073