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電絮凝中傳質(zhì)過(guò)程數(shù)值模擬的研究

發(fā)布時(shí)間:2018-06-15 01:36

  本文選題:電絮凝 + 質(zhì)量傳遞; 參考:《江蘇科技大學(xué)》2015年碩士論文


【摘要】:近年來(lái),重金屬?gòu)U水污染事件頻繁發(fā)生,電絮凝(EC)是處理重金屬?gòu)U水的一個(gè)重要技術(shù)。它也常常被用于難降解有機(jī)物廢水的處理。EC過(guò)程是由電極電化學(xué)反應(yīng)、物質(zhì)質(zhì)量傳遞、水解反應(yīng)和吸附反應(yīng)等多個(gè)過(guò)程組成,各個(gè)過(guò)程之間形成相互影響、相互作用的耦合關(guān)系。正是各過(guò)程之間復(fù)雜的耦合關(guān)系使得實(shí)驗(yàn)研究和工藝改進(jìn)的難度增大,制約了機(jī)理研究的進(jìn)一步深入。由于EC過(guò)程由絮體的產(chǎn)生,絮體的運(yùn)移及絮體的吸附三個(gè)過(guò)程組成,而絮體的產(chǎn)生及分布過(guò)程對(duì)污染物的去除效率產(chǎn)生重要的影響,因此本文建立了EC過(guò)程中電極電化學(xué)反應(yīng)和水解反應(yīng)模型,同時(shí)建立了EC電解和水解產(chǎn)物的質(zhì)量傳遞和動(dòng)量傳遞模型,并計(jì)算求解,對(duì)連續(xù)電絮凝過(guò)程中各物種的產(chǎn)生和傳質(zhì)規(guī)律進(jìn)行研究。研究發(fā)現(xiàn),電解產(chǎn)生的Al3+主要分布在陽(yáng)極附近,OH-分布在陰極附近,沿流程方向兩離子的量都逐漸地減少。在電解槽的前段,離子的濃差極化較弱,水解反應(yīng)為控制步驟;在電解槽的中段和后段,離子的濃差極化較強(qiáng),傳質(zhì)為控制步驟。隨著電流密度的增大,Al3+和OH-的濃度也增加;在無(wú)水解的情況下,離子的濃差極化較弱,整個(gè)電解槽溶液顯弱堿性。水解產(chǎn)物中溶解鋁主要分布在兩電極附近,而絮體鋁主要分布在兩電極中間位置,同時(shí)整個(gè)電解槽中絮體鋁占主要地位。沿流程方向,絮體鋁占總鋁的百分比逐漸增加,溶解鋁占總鋁的百分比逐漸減小。研究還發(fā)現(xiàn),在電遷移和對(duì)流的共同作用下絮體主要分布在電解槽后段的極板間的中間位置,而靠近陰極區(qū)域絮體的量幾乎為0。沿著流體流動(dòng)方向絮體的量增大,電解通道中絮體的生成量隨電流密度和停留時(shí)間的增加而增加,而在初始pH值為5-7的范圍幾乎不發(fā)生變化。同時(shí)發(fā)現(xiàn)電解槽通道中,垂直于電極方向上,絮體的分布不受停留時(shí)間、電流密度及初始pH的影響。
[Abstract]:In recent years, heavy metal wastewater pollution incidents occur frequently, and electroflocculation (ECC) is an important technology to treat heavy metal wastewater. It is also often used in the treatment of refractory organic wastewater. EC process is composed of electrochemical reaction of electrode, mass transfer of substance, hydrolysis reaction and adsorption reaction. The coupling of interactions. It is the complicated coupling relationship between the processes that makes the experimental research and process improvement more difficult, which restricts the further study of mechanism. The EC process consists of three processes: floc generation, floc transport and floc adsorption, and the floc generation and distribution process have an important effect on the removal efficiency of pollutants. In this paper, the electrochemical reaction and hydrolysis reaction model of electrode in EC process is established, and the mass transfer and momentum transfer model of EC electrolysis and hydrolysate are established, and the solution is calculated. The generation and mass transfer of species during continuous electrocoagulation were studied. It is found that the Al3 produced by electrolysis mainly distributes in the cathode near the anode, and the amount of the two ions decreases gradually along the flow direction. In the front section of the electrolyzer, the concentration polarization of the ion is weak, the hydrolysis reaction is the control step, and the concentration polarization of the ion is stronger in the middle and the later part of the cell, and the mass transfer is the control step. The concentration of Al3 and OH- also increased with the increase of current density, and the concentration polarization of ions was weak without hydrolysis, and the whole electrolytic cell solution showed weak alkalinity. The dissolved aluminum in the hydrolyzed product mainly distributes near the two electrodes, while the floc aluminum mainly distributes in the middle position of the two electrodes, and the floc aluminum occupies the main position in the whole electrolysis cell. Along the flow direction, the percentage of floc aluminum to total aluminum increases gradually, while the percentage of dissolved aluminum to total aluminum decreases gradually. It is also found that the floc mainly distributes in the middle position between the polar plates in the back section of the electrolytic cell under the combined action of electromigration and convection, and the amount of floc near the cathode area is almost 0. The amount of floc in the electrolytic channel increases with the increase of current density and residence time, but almost does not change in the range of initial pH value of 5-7. At the same time, it is found that the distribution of floc is not affected by residence time, current density and initial pH in the electrolytic cell channel perpendicular to the electrode direction.
【學(xué)位授予單位】:江蘇科技大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2015
【分類號(hào)】:X703

【參考文獻(xiàn)】

相關(guān)期刊論文 前7條

1 宋均軻;錢斌;;電絮凝技術(shù)在水處理中的應(yīng)用[J];廣州化工;2011年14期

2 孟超;孟慶慶;;化學(xué)沉淀法處理含鉻電鍍廢水的工程應(yīng)用研究[J];環(huán)境科學(xué)與管理;2013年04期

3 劉旭東;姜湘山;;電凝聚法處理含重金屬綜合廢水的試驗(yàn)研究[J];環(huán)境保護(hù)科學(xué);2005年06期

4 求淵;施勇琪;張相陽(yáng);李德勝;況武;;脈沖電絮凝處理電鍍含鉻廢水的實(shí)驗(yàn)研究[J];環(huán)境工程學(xué)報(bào);2009年06期

5 徐旭東;王中琪;周乃磊;;不銹鋼-鋁電極電絮凝處理含銅廢水的試驗(yàn)研究[J];安全與環(huán)境工程;2010年02期

6 胡齊福;吳遵義;黃德便;張晶夢(mèng);;反滲透膜技術(shù)處理含鎳廢水[J];水處理技術(shù);2007年09期

7 施銀桃;夏東升;曾慶福;;電絮凝氣浮法處理分散艷藍(lán)E-4R廢水的研究[J];應(yīng)用化工;2009年03期

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