本文關鍵詞： 混凝 微濾 給水 腐殖酸 膜污染　出處：《沈陽建筑大學》2013年碩士論文　論文類型：學位論文

【摘要】：飲用水的質量直接關系到人們的身體健康,隨著污染的加劇與飲用水標準的嚴格,如何去除水中的污染物來保障飲用水安全,已經(jīng)成為了水處理技術中的熱門問題。天然有機物是水中消毒副產(chǎn)物的前體物,而腐殖質是地面水源中含量最高的天然有機物。 本文選用混凝-微濾工藝處理給水中的腐殖酸,通過水溫、pH、腐殖酸濃度、混凝劑投加量、混凝劑種類五種因素考察對腐殖酸去除率、鐵離子殘留量和濁度去除率的影響。運用正交試驗法分析這些因素的最優(yōu)方案與對腐殖酸去除率與膜污染的影響主次,分析膜污染的機理,主要結論如下： 在不投加混凝劑直接膜過濾時,腐殖酸的去除率僅為12.8%,而加入混凝劑后,可以達到90%以上。各個因素對混凝-微濾工藝運行的影響趨勢也有所不同。水溫、腐殖酸濃度對運行效果的影響是成正比關系的,而pH則相反,pH越高,工藝運行效果越差�；炷齽┩都恿繉ζ溆绊懖⒉皇浅示�性關系的,在投加量為0.6mmol/L時,工藝運行的效果最好。三氯化鐵的腐殖酸去除效率要比聚合氯化鐵高,而鐵離子的殘留量與濁度去除率也是三氯化鐵高與聚合氯化鐵。 混凝-微濾工藝的去除效率與膜污染程度在一定程度上取決于混凝后絮體的形成狀態(tài),不同理化性質的混凝絮體形成的泥餅層有所不同。吸附在膜表面的顆粒越小,顆粒之間的縫隙就越小,形成的泥餅層就比較致密,膜阻力較大。此時透過膜的的顆粒都是粒徑相對較小的,而小粒徑的顆粒往往對膜孔產(chǎn)生較嚴重的污染。 通過正交試驗的分析可知,混凝-微濾工藝對腐殖酸去除效率的四個影響因素中,混凝劑投加濃度對工藝的腐殖酸去除效率影響最大,其次是pH和腐殖酸濃度,影響最小的為水溫。最優(yōu)工藝條件為：腐殖酸濃度為6mg／L、水溫10-C、pH為6、混凝劑濃度為0.6mmol/L,工藝在此組合條件下對腐殖酸的去除效率最高�；炷�-微濾工藝去除飲用水中腐殖酸的Jt／Jo值最優(yōu)工藝條件為：腐殖酸濃度為6mg/L、水溫20℃、PH為6、混凝劑濃度為1mmol/L。其中,混凝劑濃度對膜污染的影響最大,其次是腐殖酸濃度和水溫,影響最小的為pH。
[Abstract]:The quality of drinking water is directly related to people's health. With the intensification of pollution and strict standards of drinking water, how to remove pollutants in water to ensure the safety of drinking water. Natural organic matter is the precursor of disinfection by-product in water, and humus is the most abundant natural organic substance in surface water source. In this paper, the humic acid in feed water was treated by coagulation-microfiltration process. The removal rate of humic acid was investigated by five factors: water temperature, humic acid concentration, coagulant dosage and coagulant type. The effects of iron ion residue and turbidity removal efficiency were analyzed by orthogonal test. The optimal scheme and the effect on humic acid removal efficiency and membrane fouling were analyzed by orthogonal test. The mechanism of membrane fouling was analyzed. The main conclusions were as follows: The removal rate of humic acid was only 12.8when direct membrane filtration was not added with coagulant, but after adding coagulant. The effect of different factors on the operation of coagulation-microfiltration process is different. The effect of water temperature and humic acid concentration on the operation effect is proportional, but pH is the opposite. The higher the pH, the worse the operation effect of the process. The effect of coagulant dosage on it is not linear, when the dosage is 0.6 mmol / L. The humic acid removal efficiency of ferric trichloride is higher than that of polyferric chloride, and the removal rate of iron ion residue and turbidity is also higher than that of polyferric chloride and ferric trichloride. The removal efficiency and membrane fouling degree of coagulation-microfiltration process depend to some extent on the formation of flocs after coagulation. The smaller the particles adsorbed on the surface of the membrane, the smaller the gap between the particles, and the denser the mud cake layer formed. At this time, the particles passing through the membrane are relatively small in size, and the particles with small particle size tend to pollute the membrane pore seriously. Through the analysis of orthogonal experiment, we can know that the coagulation-microfiltration process has the greatest influence on the removal efficiency of humic acid among the four factors which affect the removal efficiency of humic acid. The optimum technological conditions are as follows: humic acid concentration is 6 mg / L, water temperature is 10 ~ (-C), pH is 6, coagulant concentration is 0.6 mmol / L. The optimum Jt/Jo value of coagulation-microfiltration process for removal of humic acid in drinking water was as follows: humic acid concentration was 6 mg / L, water temperature was 20 鈩，

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