【摘要】：膜分離技術(shù)主要包括微濾、超濾、納濾和反滲透等方法,由于其具有分離效率高、操作方便、能耗低、工作環(huán)境安全、無(wú)污染等諸多優(yōu)點(diǎn),在食品、醫(yī)藥、冶金、能源、化工、環(huán)保等領(lǐng)域有著十分廣泛的應(yīng)用。根據(jù)膜制備材料的不同,可將其分為兩大類(lèi):有機(jī)膜和無(wú)機(jī)膜。無(wú)機(jī)膜以陶瓷膜為主導(dǎo),具有耐高溫、耐酸堿、使用壽命長(zhǎng)等優(yōu)點(diǎn),擁有十分廣闊的發(fā)展前景。目前,商品化的陶瓷膜一般為非對(duì)稱(chēng)形式,在制備過(guò)程中需要進(jìn)行多次的燒結(jié)和涂膜,不僅過(guò)程繁瑣,而且消耗大量的能源,導(dǎo)致陶瓷膜制備成本居高不下。對(duì)于這種狀況,本文以?xún)煞N不同的成型工藝制備支撐體和分離層,進(jìn)行一次性共燒結(jié)得到陶瓷膜。為探究其分離能力,用染料進(jìn)行過(guò)濾性能測(cè)試,最后采用有機(jī)無(wú)機(jī)復(fù)合膜提高對(duì)染料的去除率。針對(duì)支撐體燒結(jié)溫度過(guò)高的問(wèn)題,對(duì)其進(jìn)行低溫?zé)Y(jié)的研究。向骨料中加入復(fù)合助燒劑(NaSiO3+TiO2+CaCO3+MgO)降低支撐體的燒結(jié)溫度。探討了Na Si O3的加入量對(duì)支撐體各性能的影響,發(fā)現(xiàn)NaSiO3的添加對(duì)支撐體低溫?zé)Y(jié)由明顯的促進(jìn)作用,但加入量需要控制得當(dāng)。通過(guò)正交實(shí)驗(yàn)確定nasio3含量,成孔劑含量、粘結(jié)劑含量和保溫時(shí)間的最優(yōu)方案為4%、6%、0.6%和2h。在此最優(yōu)條件下,重點(diǎn)研究溫度的影響,在較低的溫度區(qū)間1400-1450℃得到的陶瓷膜各性能較優(yōu),適宜作為更精密的分離層載體使用。對(duì)傳統(tǒng)注凝成型工藝進(jìn)行改進(jìn),以mma作為有機(jī)單體,通過(guò)本體聚合后得到預(yù)聚液與粉體骨料混合制成涂膜液,涂覆在支撐體生坯上干燥后形成凝膠層,隨后進(jìn)行共燒結(jié)得到非對(duì)稱(chēng)陶瓷膜。實(shí)驗(yàn)結(jié)果表明:當(dāng)引發(fā)劑用量為0.1%,于90℃水浴中加熱11.5min,得到的預(yù)聚液粘度為350mpa?s左右,流動(dòng)性良好�？膳c氧化鋁粉體混合作為涂膜液使用。涂膜液中粉體粒徑越小、漿料固相體積分?jǐn)?shù)越大,燒結(jié)溫度越高,得到的陶瓷膜純水通量、孔隙率和孔徑越小。為了得到孔徑小,且分布更均勻的陶瓷膜,選擇平均粒徑為4.49μm的原料,控制漿料固相體積分?jǐn)?shù)和燒結(jié)溫度為50%和1420℃。通過(guò)對(duì)兩種不同染料進(jìn)行過(guò)濾后發(fā)現(xiàn),mma注凝成型制得的陶瓷膜比傳統(tǒng)注漿成型制得支撐體過(guò)濾性能更好,說(shuō)明mma體系注凝成型工藝在分離層制備方向具備一定的應(yīng)用價(jià)值。為了進(jìn)一步強(qiáng)化膜過(guò)濾性能,選擇以低成本的有機(jī)膜負(fù)載于陶瓷膜上,通過(guò)相轉(zhuǎn)化制得有機(jī)/無(wú)機(jī)復(fù)合膜。探究聚醚砜濃度、浸漬時(shí)間、浸漬溫度和凝固浴溫度對(duì)復(fù)合膜性能的影響。結(jié)果表明聚醚砜濃度和浸漬溫度越高,復(fù)合膜純水通量越低,對(duì)直接染料去除率越高。凝固浴溫度越高,水通量越高,對(duì)直接染料去除率降低。浸漬時(shí)間則幾乎沒(méi)有影響。通過(guò)控制變量法在聚醚砜濃度為15%,浸漬時(shí)間為1h,浸漬溫度為40℃、凝固浴溫度為20℃時(shí),得到的復(fù)合膜性能最佳,此時(shí)膜純水通量為416.8 L?m-2?h-1,對(duì)直接染料去除率可以達(dá)到94.12%。
[Abstract]:Membrane separation technology mainly includes microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Because of its advantages of high separation efficiency, convenient operation, low energy consumption, safe working environment, no pollution and so on, it is widely used in food, medicine, metallurgy, energy, chemical industry, etc. Environmental protection and other fields have a very wide range of applications. According to the different preparation materials, the membrane can be divided into two categories: organic membrane and inorganic membrane. Inorganic membrane, which is dominated by ceramic membrane, has the advantages of high temperature resistance, acid and alkali resistance and long service life. At present, the commoditized ceramic membrane is usually in the form of asymmetric, and it is necessary to sintering and coating many times in the process of preparation, which is not only cumbersome but also consumes a lot of energy, which leads to the high cost of ceramic membrane preparation. In this paper, support and separation layer were prepared by two different molding processes, and ceramic membranes were prepared by one-time co-sintering. In order to study its separation ability, the filtration performance was tested with dyes, and the removal rate of dyes was improved by organic inorganic composite membrane. Aiming at the problem of high sintering temperature of the support, the low temperature sintering of the support was studied. The sintering temperature of the support was reduced by adding a composite sintering aid (NaSiO3 TiO2 CaCO3 MgO) to the aggregate. The effect of Na Si O3 addition on the properties of the support was discussed. It was found that the addition of NaSiO3 promoted the sintering of the support at low temperature obviously, but the addition amount needed to be controlled properly. The optimum scheme of nasio3 content, pore-forming agent content, binder content and holding time was determined by orthogonal experiment. Under the optimum conditions, the effect of temperature on the ceramic membrane was studied. The ceramic membrane obtained at 1400-1450 鈩，

本文編號(hào)：2293477