本文選題：剩余污泥　切入點(diǎn)：堿-熱低溫預(yù)處理　出處：《西安理工大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：隨著我國(guó)城鎮(zhèn)基礎(chǔ)設(shè)施的不斷完善,城鎮(zhèn)污水處理廠污水處理率顯著提高,二級(jí)生化過(guò)程產(chǎn)生的剩余污泥量也大幅增加。對(duì)污泥進(jìn)行厭氧消化處置,將污泥中的有機(jī)質(zhì)轉(zhuǎn)化成能量物質(zhì)進(jìn)行再生利用,是未來(lái)污水處理廠實(shí)現(xiàn)可持續(xù)運(yùn)行的關(guān)鍵。但受剩余污泥胞外結(jié)構(gòu)和細(xì)胞的細(xì)胞壁難以破壁水解的影響,致使污泥水解發(fā)酵過(guò)程緩慢,在一定的時(shí)間內(nèi)產(chǎn)氣效率低下,有機(jī)質(zhì)最終的利用率低,不僅制約了污泥厭氧消化技術(shù)的推廣實(shí)施,還影響消化后污泥的最終處置。通過(guò)污泥預(yù)處理技術(shù)破壞剩余污泥的胞外結(jié)構(gòu),加速細(xì)胞破壁水解,可有效改善污泥厭氧消化效能。本課題采用堿-熱低溫?zé)崴忸A(yù)處理技術(shù),以藥劑和熱能消耗量最小為條件,獲得污泥堿-熱低溫預(yù)處理的最優(yōu)參數(shù),以使在加速細(xì)胞破壁水解的同時(shí)節(jié)約預(yù)處理能耗;開(kāi)展污泥厭氧消化生物化學(xué)甲烷勢(shì)(Biochemical Mathane Potential,BMP)實(shí)驗(yàn),探討堿-熱低溫預(yù)處理提高污泥厭氧消化產(chǎn)氣效率的程度及實(shí)踐應(yīng)用的可行性。獲得的研究結(jié)果如下:1、通過(guò)正交實(shí)驗(yàn),確定了堿-熱預(yù)處理的最佳運(yùn)行參數(shù)。污泥在不同水熱溫度(70℃、80℃、90℃)、不同水熱時(shí)間(7h、8h、9h)、不同堿劑量(0.025、0.05、0.075g/gTSNaOH)預(yù)處理?xiàng)l件下,進(jìn)行正交實(shí)驗(yàn),在藥劑與熱能消耗量最小的條件下,SCOD溶出率、上清液中蛋白質(zhì)、碳水化合物的濃度達(dá)到最大時(shí),獲得了堿-熱預(yù)處理最佳運(yùn)行條件為水熱溫度為70℃、NaOH劑量為0.025g/gTS、水熱時(shí)間為8h;污泥經(jīng)預(yù)處理,VSS/TS平均從57.5%下降到45.9%,VSS去除率約為12%,污泥的沉降性能最好,SV為55.3%。2、水熱溫度及NaOH劑量對(duì)污泥的破解程度影響顯著。實(shí)驗(yàn)結(jié)果表明:隨著水熱溫度的升高(從50℃升高到100℃),污泥絮體和細(xì)胞的破碎程度增加顯著,SCOD、蛋白質(zhì)和碳水化合物的溶出和釋放量分別增加了 6.5倍、4.5倍和36.9倍,且在70℃左右時(shí),溶出和釋放速率顯著增加;釋放出的物質(zhì)的分子量隨溫度升高呈逐步降低趨勢(shì),在水熱溫度為70℃以上時(shí),污泥熱解產(chǎn)物中小分子量物質(zhì)所占比重較大,這有助于后續(xù)厭氧消化反應(yīng)的進(jìn)行。隨著堿劑量的增加,從污泥中溶出的SCOD、蛋白質(zhì)、碳水化合物和總磷的含量不斷增大;當(dāng)NaOH的劑量大于0.05g/gTS時(shí),蛋白質(zhì)和總磷的含量急劇增加,說(shuō)明此時(shí)大部分細(xì)胞的細(xì)胞壁發(fā)生了破裂,使大量的細(xì)胞物質(zhì)釋放出來(lái),而當(dāng)NaOH的劑量在0-0.05g/gTS時(shí),僅發(fā)生了污泥細(xì)胞外部的絮體離散和解體及小部分細(xì)胞的破解。3、經(jīng)堿-熱預(yù)處理后的污泥及上清液,厭氧消化效能得到較大改善。污泥經(jīng)堿熱預(yù)處理和厭氧消化處理(15d)后,污泥混合液和上清液VSS的去除率分別為31%和37%,比原污泥分別高出15%和21%;甲烷產(chǎn)率分別為154.29mLCH4/gVSS和55.14mLCH4/gVSS,比原污泥分別高出6.6倍和1.7倍。
[Abstract]:With the continuous improvement of urban infrastructure in China, the sewage treatment rate of urban sewage treatment plant has been significantly increased, and the excess sludge produced by the secondary biochemical process has also increased significantly. Converting organic matter from sludge into energy material for regeneration is the key to realize sustainable operation of sewage treatment plant in the future. However, it is difficult to hydrolyze the cell wall by the extracellular structure of excess sludge and cell wall. The process of sludge hydrolysis and fermentation is slow, the efficiency of gas production is low and the utilization rate of organic matter is low, which not only restricts the popularization and implementation of sludge anaerobic digestion technology. It also affects the final disposal of sludge after digestion. By using sludge pretreatment technology to destroy the extracellular structure of excess sludge and accelerate cell wall breaking hydrolysis, the anaerobic digestion efficiency of sludge can be effectively improved. The optimum parameters of alkali-thermo-low temperature pretreatment of sludge were obtained under the condition of minimal consumption of medicament and heat energy, in order to accelerate cell wall breaking hydrolysis and save energy consumption of pretreatment, the sludge anaerobic digestion of biochemical methane potential Biochemical Mathane potential (BMP) experiment was carried out. This paper discusses the degree of improving the efficiency of anaerobic digestion of sludge and the feasibility of practical application of alkali-thermo-low temperature pretreatment. The results obtained are as follows: 1, through orthogonal experiment, The optimum operation parameters of alkali-thermal pretreatment were determined. The orthogonal experiments were carried out under the conditions of different hydrothermal temperature 70 鈩，

本文編號(hào)：1644026