本文選題：正滲透 + 城市污水��； 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：正滲透工藝作為膜處理中的新型技術(shù),具有節(jié)能環(huán)保、高效的耐污染性能、出水水質(zhì)優(yōu)良等優(yōu)點。由于無需外加壓力,減弱了濾餅層的形成和運行成本,使正滲透工藝在污水處理中備受關(guān)注。傳統(tǒng)工藝處理后污水排放入自然水體造成的水環(huán)境中污染物,對淡水資源和近海環(huán)境造成極大的威脅。使用來源廣泛的海水作為汲取液稀釋后直接排放,可滿足高滲透壓及安全無毒的汲取液需求,在進一步降低能耗的同時,提升了工藝的簡易性,也由于正滲透對污染物的高截留率優(yōu)化了出水水質(zhì),對水環(huán)境的保護和利用具有重要意義。本課題主要對海水汲取液進行正滲透污水處理的效能進行考察。考察了海水汲取液的運行特性,如錯流速率與溫度對通量和溶質(zhì)反滲的影響,以及海水汲取液的濃縮能力。通過分析得出高溫高錯流速率對通量和溶質(zhì)反滲都有大幅提升,PRO模式中增加幅度大于FO模式。污水實驗測定反應(yīng)前后污染物濃度如COD、總磷、氨氮等含量,以考察正滲透膜對污染物截留性能。觀測長期運行對通量帶來的影響,以及溶質(zhì)反滲隨膜污染情況增加的變化,考察膜污染對正滲透膜性能的影響。測量主要金屬離子的反滲程度,分析金屬離子在膜表面沉積吸附,或穿過膜滲透入原料液程度。實驗得出物理清洗可以去除活性層表面污染層獲得一定程度的通量恢復(fù),但支撐層內(nèi)部污染很難除去。正滲透工藝在長時間運行時對污染物的截留率能夠達到90%以上,二價離子鈣鎂離子大多附著于膜表面,反滲程度可以忽略。膜通量隨著膜孔堵塞程度增加而降低,而PRO運行模式下隨著支撐層內(nèi)部污染的加劇,溶質(zhì)反滲逐漸降低,但FO模式中鹽離子反滲程度隨著活性層表面污染加劇而升高。正滲透過程中的濃差極化現(xiàn)象由于不可逆的特性成為降低正滲透性能的主要因素。本研究對污水中主要成分進行模擬,探討不同運行模式與不同污染物對濃差極化程度的影響。實驗得出有機物是影響濃差極化的污染成分,尤其是支撐層內(nèi)部的濃差極化現(xiàn)象,而混合污染中無機鹽的影響可以忽略。對于相同濃度的原料液,高濃度的汲取液引起的濃差極化程度較小。對于相同濃度的汲取液,低濃度的原料液引起的濃差極化程度較低。在正滲透過程中由于靜電斥力對蛋白質(zhì)的濃縮效果較好,但對于蛋白質(zhì)與其他污染物質(zhì)的混合溶液,蛋白質(zhì)的凝聚強化了濃差極化層的形成。
[Abstract]:As a new technology in membrane treatment, normal osmosis process has the advantages of energy saving, environmental protection, high efficiency pollution resistance and good effluent quality. The formation and operation cost of the filter cake layer is weakened without external pressure, which makes the normal osmotic process become more and more important in wastewater treatment. The pollutants in the water environment caused by the sewage discharged into the natural water body after the treatment of the traditional process pose a great threat to the freshwater resources and the offshore environment. The direct discharge of seawater from a wide range of sources after dilution can meet the requirements of high osmotic pressure and safety and non-toxic solution, while further reducing energy consumption and improving the simplicity of the process. Because the high rejection rate of positive osmosis to pollutants optimizes the effluent quality, it is of great significance for the protection and utilization of water environment. The purpose of this paper is to investigate the efficiency of seawater-water sewerage treatment. The effects of cross-flow rate and temperature on flux and solute reverse osmosis as well as the concentration capacity of seawater extract were investigated. It is found that the high temperature and high cross-flow rate has a significant increase in flux and solute reverse osmosis in the pro model, which is larger than that in the FO model. The concentration of pollutants such as COD, total phosphorus and ammonia nitrogen were measured before and after the reaction in order to investigate the retention of pollutants by osmotic membrane. The effects of long-term operation on flux and the change of solute reverse osmosis with membrane fouling were observed and the effects of membrane fouling on the performance of normal osmotic membrane were investigated. The degree of reverse osmosis of main metal ions was measured, and the degree of metal ion deposition and adsorption on the membrane surface or permeating through the membrane into the raw material solution was analyzed. The results show that physical cleaning can remove the surface fouling layer of the active layer to a certain extent, but it is difficult to remove the internal pollution of the supporting layer. The rejection rate of pollutants can reach more than 90% when the process of normal osmosis is running for a long time, and the bivalent ion calcium and magnesium ions are mostly attached to the membrane surface, and the degree of reverse osmosis can be neglected. The membrane flux decreases with the increase of membrane pore plugging degree, while the solute reverse osmosis decreases with the increase of the pollution inside the supporting layer in pro mode, but the salt ion reverse osmosis degree in FO mode increases with the increase of the surface pollution of the active layer. The concentration polarization phenomenon in the normal osmotic process is the main factor of decreasing the normal osmotic performance due to the irreversible characteristics. In this study, the main components of sewage were simulated, and the effects of different operating modes and pollutants on the concentration polarization were discussed. The results show that organic matter is the pollutant that affects the concentration polarization, especially the concentration polarization phenomenon in the supporting layer, but the influence of inorganic salts in the mixed pollution can be neglected. For the same concentration of the raw liquid, the concentration polarization caused by the high concentration extraction solution is small. For the same concentration of absorbent, the concentration polarization caused by low concentration of feedstock solution is lower. In the normal osmotic process, the electrostatic repulsive force has a good effect on the concentration of protein, but for the mixed solution of protein and other pollutants, the condensation of protein strengthens the formation of the concentration polarization layer.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X703

【參考文獻】

相關(guān)期刊論文 前1條

1 張高旗;劉海寧;張凱松;;正滲透處理生活污水過程中的膜污染研究[J];中國環(huán)境科學(xué);2013年12期

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本文編號：2071780