【摘要】：膜技術(shù)作為高效的分離新技術(shù),在水處理中有著很好的發(fā)展前景,受到越來(lái)越多的關(guān)注,但膜技術(shù)尚不成熟,其面臨的一個(gè)主要問(wèn)題是由膜的親水性不足帶來(lái)的易受污染,清洗頻率增加進(jìn)而導(dǎo)致膜壽命降低,成本上升。所以,如何提高膜的親水性及耐污染性,成為現(xiàn)階段研究的重要方向。本論文利用載銀羥基磷灰石HAP/Ag作為改性材料,以共混法制備改性聚醚砜超濾膜,探索了制備時(shí)適宜的各材料添加比例,表征及測(cè)試了制備后的改性膜性能,并對(duì)改性膜的阻力變化進(jìn)行了分析。主要結(jié)論如下:(1)負(fù)載銀納米羥基磷灰石材料(HAP/Ag)在結(jié)構(gòu)特征、尺寸大小、晶型結(jié)構(gòu)和特征官能團(tuán)等方面均與羥基磷灰石(HAP)相似性很高,表明HAP/Ag材料很好地維持了HAP材料原本的結(jié)構(gòu)和性質(zhì);(2)隨著改性材料HAP/Ag的添加,聚醚砜樹(shù)脂(PES)膜的水通量、截留率和接觸角有所改變:在添加量為2%時(shí)改性膜的水通量達(dá)到最大值,較原膜通量提高了397%;當(dāng)添加量為5%時(shí),截留率達(dá)到了最大值97%,高于原始膜64%的截留效果;當(dāng)添加量為3%時(shí),接觸角最小,較原始膜的接觸角下降了19.27%,表現(xiàn)出很好的親水性能;另外,改性超濾膜的彈性形變量增大,最大拉力也逐漸增加;(3)添加改性材料后制備的所有PES超濾膜周圍均產(chǎn)生了直徑大小不一的抑菌圈,濃度接觸實(shí)驗(yàn)進(jìn)一步驗(yàn)證隨著HAP/Ag添加量的不同,抑菌效果有所差異;銀離子浸出量大小及速率實(shí)驗(yàn)驗(yàn)證得出材料中銀離子具有初期快速溶出,后期緩慢釋放的特性;(4)通過(guò)正交分析,鑄膜液配比的優(yōu)化條件為:PES18%,聚乙烯基吡咯烷酮(PVP)6%,HAP/Ag 2%;優(yōu)化后的改性PES超濾膜其純水通量為205.88 L·m-2·h-1,截留率為98.94%,水通量衰減系數(shù)為0.31,抗污性能良好。(5)優(yōu)化的PES改性膜對(duì)COD的去除率達(dá)到了54.5%,對(duì)濁度的去除率為90.3%,與未改性的PES超濾膜相比,其去除率分別提高了1.20倍和1.93倍;兩者有相同的阻力變化趨勢(shì),其中內(nèi)部污染阻力和膜的固有阻力是導(dǎo)致兩組膜在超濾過(guò)程中通量衰減的主要因素,而優(yōu)化后的PES改性膜其阻力值一直低于未改性的PES膜,表明改性后的膜較原始膜,有更強(qiáng)的抗污能力。
[Abstract]:Membrane technology, as a new separation technology with high efficiency, has a good prospect in water treatment and has attracted more and more attention. However, the membrane technology is still immature, and one of the main problems it faces is the vulnerability to contamination caused by the lack of hydrophilicity of membrane. The increase of cleaning frequency leads to the decrease of membrane life and the increase of cost. Therefore, how to improve the hydrophilicity and pollution resistance of the membrane has become an important research direction at this stage. In this paper, the modified polyethersulfone ultrafiltration membrane was prepared by blending with silver loaded hydroxyapatite (HAP/Ag) as the modified material. The suitable proportion of each material was explored, and the properties of the modified membrane were characterized and tested. The change of resistance of the modified membrane was analyzed. The main conclusions are as follows: (1) the silver loaded nano-hydroxyapatite (HAP/Ag) is similar to hydroxyapatite (HAP) in structure, size, crystal structure and functional groups. The results show that the structure and properties of HAP materials are well maintained by HAP/Ag materials. (2) with the addition of the modified material HAP/Ag, the water flux, rejection rate and contact angle of the (PES) membrane were changed: the water flux of the modified membrane reached the maximum value when the addition amount was 2, and the flux of the modified membrane was increased by 397% compared with the original membrane flux; When the addition amount is 5, the rejection rate reaches the maximum 97, which is higher than 64% of the original membrane, and when the addition is 3, the contact angle is the smallest, which is 19.27 lower than that of the original membrane, showing good hydrophilicity. In addition, the elastic shape of the modified ultrafiltration membrane increases, and the maximum tensile force increases gradually. (3) all the PES ultrafiltration membranes prepared by adding modified materials produced different diameter bacteriostasis circles. The concentration contact experiment further verified that the bacteriostatic effect was different with the amount of HAP/Ag added; The experimental results of silver ion leaching amount and rate show that the silver ion has the characteristics of rapid dissolution in the initial stage and slow release in the later stage. (4) by orthogonal analysis, the optimum conditions of casting liquid ratio are as follows: PES18%, polyvinylpyrrolidone (PVP) 6 and HAP / Ag _ (2); The optimized modified PES ultrafiltration membrane has a pure water flux of 205.88 L m ~ (-2) h-1, a rejection rate of 98.94 and a water flux attenuation coefficient of 0.31. (5) the removal rate of COD by optimized PES modified membrane was 54.5%, and the turbidity removal rate was 90.30.The removal rate was 1.20 times and 1.93 times higher than that of unmodified PES ultrafiltration membrane, respectively. The internal fouling resistance and the intrinsic resistance of the two groups of membranes were the main factors leading to the flux attenuation of the two groups of membranes during ultrafiltration, while the optimized PES modified membrane had a lower resistance value than the unmodified PES membrane. The results showed that the modified membrane had stronger antifouling ability than the original membrane.
【學(xué)位授予單位】：中國(guó)礦業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：X703

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本文編號(hào)：2412503