發(fā)布時(shí)間：2018-01-02 13:33

  本文關(guān)鍵詞：循環(huán)推流式固定化微生物反應(yīng)器的設(shè)計(jì)及優(yōu)化研究　出處：《廣西大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 固定化微生物反應(yīng)器 循環(huán)推流 設(shè)計(jì) 數(shù)值模擬 結(jié)構(gòu)優(yōu)化

【摘要】：城鎮(zhèn)生活污水是一種潛在的水資源,對(duì)其凈化處理并再利用,既能減輕水體污染程度,改善生態(tài)環(huán)境,又能解決城鎮(zhèn)的缺水問題。固定化微生物技術(shù)因其獨(dú)特的優(yōu)越性成為污水處理及環(huán)境保護(hù)領(lǐng)域的研究熱點(diǎn)。然而現(xiàn)有的固定化微生物反應(yīng)器不適用于較為分散、難以收集且多滯留在水深較淺的湖塘、水洼等區(qū)域的城鎮(zhèn)生活污水。針對(duì)廣西壯族自治區(qū)寧明縣愛店村某生物氧化塘污水處理項(xiàng)目,嘗試研發(fā)設(shè)計(jì)一種循環(huán)推流式固定化微生物反應(yīng)器。主要包括反應(yīng)器筒體設(shè)計(jì)、固定化微生物載體的選擇以及曝氣系統(tǒng)的設(shè)計(jì)。反應(yīng)器內(nèi)流場(chǎng)的流體力學(xué)行為十分復(fù)雜。通過對(duì)氣-液-固三相模型的簡(jiǎn)化、氣液兩相流的形態(tài)研究、氣-液相間氧的傳質(zhì)以及循環(huán)推流原理分析,有助于明確影響反應(yīng)器性能的設(shè)計(jì)參數(shù),為進(jìn)一步改善和優(yōu)化反應(yīng)器的結(jié)構(gòu)提供依據(jù)。根據(jù)曝氣頭安裝高度分別為650 mm,750 mm,850 mm,定義方案A、B、C為三種不同結(jié)構(gòu)反應(yīng)器。利用計(jì)算流體力學(xué)軟件Fluent 6.3對(duì)反應(yīng)器內(nèi)部流場(chǎng)進(jìn)行數(shù)值模擬。通過對(duì)流體速度云圖、速度矢量圖以及液相出口速度分布圖進(jìn)行分析,結(jié)果表明方案A中曝氣頭上方出現(xiàn)大的漩渦,且液相流速小于0.25 m·s1；方案C中曝氣產(chǎn)生的軸向力不能充分帶動(dòng)液相流上升,且二分之一出口面積的液相速度小于0.05 m·s-1；方案B既有充足的升程供空氣與水之間的氧的傳質(zhì),又有較高的液相出口速度保證流體的循環(huán)。因此方案B是最佳方案,即最佳曝氣安裝高度為750 mm。同樣方法對(duì)曝氣量不同的方案B、D、E進(jìn)行數(shù)值模擬,其模擬結(jié)果為方案E,即曝氣量為0.5 kg·h-1 時(shí),液相出口速率最大,有利于流體循環(huán)。為驗(yàn)證數(shù)值模擬結(jié)果的準(zhǔn)確性和可靠性,設(shè)計(jì)一套試驗(yàn)方案：以清水作為試驗(yàn)對(duì)象,利用Na2SO3作為還原劑進(jìn)行消氧,CoCl2作為催化劑加快消氧速率。由不同曝氣頭安裝高度的溶解氧變化曲線圖可知,與方案A和方案C相比,方案B充氧速率較快；由不同曝氣量的的溶解氧變化曲線圖可知,方案E的充氧速率最快。實(shí)驗(yàn)結(jié)果均與數(shù)值模擬結(jié)果一致。將優(yōu)化后的反應(yīng)器置于氧化塘內(nèi)運(yùn)行,經(jīng)過30天的水質(zhì)監(jiān)測(cè),水體中化學(xué)需氧量濃度(COD)從58 g·m-3下降到14 g·m-3,總磷濃度從0.76 g·m-3下降到0.19 g·m-3。氨氮濃度雖然有一定的波動(dòng),但整體呈下降趨勢(shì),從11g·m-3降至7 g·m-3。氧化塘內(nèi)魚類大面積死亡現(xiàn)象消失,惡臭味道不在,水藻橫生的狀況解決,整個(gè)水體中的生物圈體系得以改善,提升了氧化塘的自我降解能力。
[Abstract]:Urban domestic sewage is a kind of potential water resources. Purifying it and reusing it can not only reduce the pollution degree of water body, but also improve the ecological environment. Immobilized microorganism technology has become a research hotspot in the field of sewage treatment and environmental protection because of its unique advantages. However, the existing immobilized microbial reactor is not suitable for dispersion. It is difficult to collect and stay in shallow lake ponds, water pools and other areas of urban domestic sewage. Aiming at a biological oxidation pond sewage treatment project in Edian Village, Ningming County, Guangxi Zhuang Autonomous region. This paper attempts to develop and design a circulating push-flow immobilized microbial reactor, which mainly includes the design of reactor cylinder. The selection of immobilized microorganism carrier and the design of aeration system. The hydrodynamic behavior of the flow field in the reactor is very complicated. By simplifying the gas-liquid-solid three-phase model, the morphology of gas-liquid two-phase flow is studied. The mass transfer between gas and liquid phase and the analysis of circulation pushing principle are helpful to clarify the design parameters that affect the reactor performance. In order to further improve and optimize the reactor structure, according to the aeration head installation height of 650 mm 750mm / 850mm, defined scheme AHB. C is three kinds of reactors with different structures. The flow field in the reactor is simulated by the computational fluid dynamics software Fluent 6.3. The flow velocity cloud diagram is used to simulate the flow field in the reactor. The velocity vector diagram and the velocity distribution chart of liquid phase exit are analyzed. The results show that there is a large vortex above the aeration head in scheme A, and the liquid velocity is less than 0.25 m 路s ~ (-1). The axial force produced by aeration in scheme C can not fully drive up the liquid phase flow, and the liquid phase velocity of 1/2 exit area is less than 0.05 m 路s-1; Scheme B not only has sufficient lift for oxygen transfer between air and water, but also has high liquid phase exit velocity to ensure fluid circulation. Therefore, scheme B is the best scheme. The best aeration installation height is 750 mm. the same method is used to simulate the different aeration rate scheme BGDNE, the simulation result is scheme E, that is, when the aeration rate is 0.5 kg 路h ~ (-1), the simulation results are as follows: (1) the best aeration installation height is 750 mm 路h ~ (-1). In order to verify the accuracy and reliability of the numerical simulation results, a set of test scheme is designed: water is taken as the test object. Na2SO3 was used as reducing agent to deoxidize oxygen and CoCl2 was used as catalyst to accelerate the deoxygenation rate. According to the curves of dissolved oxygen with different aeration heads, it was compared with schemes A and C. The oxygenation rate of scheme B is faster; According to the dissolved oxygen curve of different aeration rate, the oxygen filling rate of scheme E is the fastest. The experimental results are consistent with the results of numerical simulation. The optimized reactor is put into the oxidation pond to run. After 30 days of water quality monitoring, COD) decreased from 58 g 路m -3 to 14 g 路m -3. Total phosphorus concentration decreased from 0.76 g 路m -3 to 0.19 g 路m -3. From 11g 路m-3 to 7g 路m-3.The phenomenon of fish death disappeared in the oxidation pond, the odor was not found, and the algal growth was solved, and the whole biosphere system in the water was improved. Improved the oxidation pond self-degradation ability.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X703;X172

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 張蔚萍,陳建中;固定化微生物技術(shù)在環(huán)境工程中的應(yīng)用[J];云南環(huán)境科學(xué);2003年04期

2 魏鵬;姚萌;張凱松;;曝氣方式對(duì)MBR平板膜組件流體力學(xué)特征的影響[J];中國(guó)環(huán)境科學(xué);2011年01期

，

本文編號(hào)：1369449