纳滤恒容除盐过程分析

本文介绍了纳滤恒容除盐过程。讨论和分析了间歇纳滤恒容除盐过程和连续的滤恒容除盐过程的原理和性能,并分别对不同方式的间歇纳滤恒容除盐和不同方式的连续纳滤恒容除盐客纳滤恒容除盐的应用提供理论依据和指导。     

纳滤膜在染料生产废水处理中的应用

采用超滤、纳滤集成技术,对高盐度、高色度、高COD的染料生产废水进行中试处理试验,分别考察了恒容脱盐、恒压浓缩、连续化处理等不同工艺的效果。结果表明,纳滤膜对COD的去除率大于90％,对色度去除率基本为100％,对染料截留率大于97％,能有效截留废水中的染料和有机物。同时一价盐（NaCl）大部分能透过膜。     

PPES中空纤维纳滤膜的染料脱盐性能研究

采用间歇渗滤恒容操作,考察了杂萘联苯聚芳醚砜(PPES)非对称中空纤维纳滤膜对染料的脱盐性能,并以活性艳蓝染料的盐溶液为分离介质对膜在高温下的分离性能进行了测试分析。结果表明,非对称PPES中空纤维纳滤膜具有良好的染料脱盐性能:在80℃、0.6 MPa下,纳滤膜对活性艳蓝(质量浓度10 g/L)和NaCl(质量浓度2 g/L)的混合溶液渗滤浓缩2倍,经过7个恒容循环操作后,透过液的电导率降至0.1 mS/cm以下。间歇渗透过程中,每个循环后增加反洗操作,有利于提高PPES中空纤维纳滤膜对染料的脱盐效率;以质量分数1.0%的EDTA二钠溶液为反洗液,膜通量恢复率最高可达98.6%。     

纳滤膜在染料生产废水处理中的应用

采用超滤、纳滤集成技术,对高盐度、高色度、高COD的染料生产废水进行中试处理试验,分别考察了恒容脱盐、恒压浓缩、连续化处理等不同工艺的效果.结果表明,纳滤膜对COD的去除率大于90%,对色度去除率基本为100%,对染料截留率大于97%,能有效截留废水中的染料和有机物,同时一价盐(NaCl)大部分能透过膜.因此,对染料废水进行脱盐,浓缩、回用及连续化处理是可行的.     

纳滤技术用于垃圾渗滤液深度处理

采用MBR和纳滤集成处理工艺对垃圾渗滤液进行了处理试验,研究了纳滤作为终端处理技术的处理效果.结果表明,纳滤对COD、色度的脱除情况很好,试验过程中膜性能稳定,透过通量和脱盐率的变化不大.纳滤的显著效果使其在垃圾渗滤液处理领域具有极大前途.     

纳滤和反渗透膜形貌结构与膜性能关系探索

纳滤和反渗透膜表面形貌结构、亲疏水性的性质与膜脱盐率、水通量等性能存在一定关系。对几款商用纳滤、反渗透膜进行表面形貌结构、表面粗糙度、亲水性表征。结果表明,纳滤膜表面平整粗糙度低、亲水性强、脱盐率较低,但水通量高。反渗透膜表面存在大量疏松的峰谷结构,比纳滤膜粗糙度更大、亲水性强。对比两款海水反渗透膜,推测调整反渗透膜"叶片"大小和数量可调节反渗透膜的脱盐率和水通量性能。     

纳滤过程去除染料酸性红18中的无机盐离子

针对染料酸性红18进行纳滤脱盐实验,研究了浓缩过程中各种离子的浓度变化情况和纳滤过程的通量变化。染料中的杂质离子经过纳滤脱除后,脱盐率几乎为100%。在离子浓度不断下降的过程中,氯离子因水合半径比硫酸根离子水合半径小,故氯离子的脱除速度更快。渗透液通量也随着原液中盐含量的减少而降低。     

纳滤纯化和浓缩染料试验

本文简介了纳滤对粗制染为溶胶脱盐净化和浓缩，制备高等纯净染料的部分试验，包括几种膜的实验室评价和工业规模中试放大试验，并对恒容纳滤脱盐和浓缩两个过程进行了数据分析，试验表明的纳滤净化和浓缩染料是经济的，先进的。     

纳滤膜分子截流量对玉米秸秆木聚糖提取液脱盐效果的影响

考察了三种不同分子截流量的纳滤膜DK1812(MWCO 150-300)、KM1812(MWCO 500)和GE1812(MWCO 1000)对木聚糖提取液脱盐效果和木聚糖回收率的影响。结果表明:在木聚糖提取液纳滤脱盐过程中,当置换体积数为4时,DK1812、KM1812和GE1812总脱盐率分别达94.08%、97.58%和90.38%,但DK1812总糖损失率最低,是较为合适的膜组件。在比较了DK1812和KM1812恒容渗滤与先浓缩再恒容渗滤两种操作方式后发现:浓缩倍数相同时,KM1812多糖损失率低于DK1812,再经过置换脱盐后,多糖损失率为18.72%,更适宜木聚糖提取液的浓缩脱盐处理。     

用纳滤技术对染料溶液脱水除盐的研究

简单介绍了纳滤膜的特性 ,详细介绍了纳滤膜对染料脱水除盐的情况和操作参数对膜性能的影响 ,并略谈了染料脱水除盐选择膜分离设备规格型号的观点。     

Diafiltration and water recovery of Reactive Brilliant Blue KN-R solution by two-stage membrane separation process

The conventional process of Reactive Brilliant Blue KN-R production is low purity, labor intensive, inconsistent in the production quality and also causes pollution. The improved process based on membrane technology still generates large volume of effluent though with low pollutants. In this paper, a two-stage membrane separation process is introduced to resolve these shortcomings, in which the first stage is used for diafiltration and concentration of dye solution, and the second is to recover the dye and salt water from the produced permeate. Comparing results from one ultrafiltration (UF) membrane (GH) and four nanofiltration (NF) membranes (AFC40, DL, CA865 and MPT-31), UF membrane ES404 showed the same dye rejection, higher permeate flux and lower sodium sulfate rejection. In the diafiltration and concentration stage, pre-concentration and constant volume diafiltration had the best salt permeability as compared to constant volume diafiltration and post-concentration in addition to variable volume diafiltration. In the dye and salt water recovery, membrane ES404 had the same dye rejection, but higher permeate flux and lower sodium sulfate rejection as compared to membrane GH. The proposed two-stage membrane separation process offers the advantages of high-purity, less labor intensive, consistent in production quality and less pollution.     

水溶性荧光染料溶液脱盐浓缩的纳滤实验研究

选用NTR7450和NF270两种纳滤膜对水溶性工业荧光染料原液进行分离，选择出透过通量大、除盐效果好和染料截留率高的纳滤膜，并对该染料溶液进行了脱盐和浓缩的间歇渗滤过程研究：在温度25℃和压力1.0MPa下，膜对染料截留率达到100％，最终料液中NaCl浓度从0.214mol／L降到0.0025mol／L,料液被浓缩了2．6倍。说明纳滤膜的间歇渗滤操作过程能够实现染料溶液的脱盐浓缩。     

HNF—130型CTA中空纤维纳滤组件的研制

本文介绍了HNF-130型CTA中空纤维纳滤组件的制备工艺和技术性能,并考察了不同操作条件对组件的产水量、脱除率的影响。     

基于纳滤膜的增白剂清洁生产工艺

采用纳滤膜分离技术替代原有的酸析工艺对增白剂合成液进行脱盐和浓缩,以提高产品质量,减少污染物排放。小试实验表明,纳滤膜对增白剂的平均截留率98 9%,对盐基本没有截留效果。清洁生产实验表明,增白剂溶液经过脱盐浓缩后,增白剂质量分数从5 0%提高到25 0%,无机盐质量分数从2 0%降低到0 05%;膜分离产品与酸析产品相比,白度和强度均有所提高,而在盐度指标上有了大幅度提高,产品整体性能得到提升;膜分离工艺所排污染物总量只有原工艺的1/4,新工艺减污效果明显;纳滤膜在使用过程中,膜通量随时间的延长而变小,这主要是凝胶层造成的,可通过酸洗使其恢复。     

四种纳滤膜对高盐废水分盐效果分析

为了使煤化工零排放高盐废水分盐产出高质量NaCl和Na_2SO_4结晶盐,提高废水处理过程的分盐效率,以宁东某煤化工零排放高盐废水的水质情况模拟配制了无机盐溶液,选取了膜1、膜2、膜3和膜4等4种商用纳滤膜,探讨了其对模拟高盐废水中的常规离子(Mg~(2+)、 Ca~(2+)、 Na~+、 K~+、 SO_4~(2-)、 Cl~-、 NO_3~-)的截留率,并考察了4种纳滤膜的水通量和分盐效果。结果表明,4种膜对阳离子的截留率从高到低依次为Ca~(2+)> Mg~(2+)> K~+> Na~+;对SO_4~(2-)的截留率为95%~99%,对Cl~-和NO_3~-截留率为负值;4种纳滤膜产水侧ρ(Cl~-)/ρ(SO_4~(2-))值由大到小依次为膜1>膜4>膜2>膜3,纳滤膜1表现出更好的无机盐离子截留率和分盐效果。     

高浓度含盐草甘膦溶液的纳滤分离实验研究

为了考察纳滤技术分离含高浓度单价盐的草甘膦溶液的可行性,采用商业化Desal-DK纳滤膜对含有高浓度NaCl的草甘膦溶液开展了分离实验研究和模拟计算。首先研究了物料浓度、跨膜压差等因素对NaCl和草甘膦的单组分溶液的体积通量及截留率的影响,并通过拟合SK（Spiegler-Kedem）方程计算得到了膜的特征参数;其次探究了Desal-DK纳滤膜对高浓度NaCl和不同浓度草甘膦混合溶液的分离效果,实验结果说明Desal-DK纳滤膜对NaCl呈现较高的透过性,而对草甘膦则呈现较高的截留性,从而能够有效实现草甘膦和NaCl的分离;最后通过对含有100 g/L NaCl和1 g/L草甘膦的混合溶液进行预浓缩-连续恒容渗滤过程的模拟计算,得到了较高浓度的草甘膦溶液和相对较纯的NaCl溶液,证明通过纳滤渗滤过程实现含草甘膦浓盐水的资源化利用是可行的。     

利用纳滤膜分离精制饱和卤水的研究

针对饱和卤水直接制碱过程需要去除硫酸根、钙离子、镁离子（SO₄^2-、Ca²⁺、Mg²⁺）等杂质离子的问题,探索了利用纳滤膜分离精制饱和卤水新工艺。通过考察NF270、DL2540、ESNA1 3种类型纳滤膜的透过通量和离子截留率,确定了选用DL2540为实验用膜;分析了DL2540纳滤膜对离子的截留性能和对盐田饱和卤水的分离性能及其对饱和卤水精制的效果。结果表明,增加同离子浓度、降低压力有利于不同价态阳离子、阴离子间的分离,DL2540纳滤膜对盐田饱和卤水中SO₄^2-、Ca²⁺、Mg²⁺截留率分别达到95%以上、30%~50%、30%~70%,对Na⁺、Cl^-截留率均低于15%,进一步证明DL2540纳滤膜具有较好的稳定性和二价离子截留效果,在饱和卤水精制上展示出较好的应用前景。     

Laboratory Studies on Membrane Deoiling of Lecithin

Deoiling of lecithin using a nonporous membrane was examined in a favorable solvent (hexane) medium with soy and rice bran lecithins. During the membrane process, the acetone insoluble (AI) content of soy lecithin increased from 63.2 to 81.0% in a single step batch operation. The membrane exhibited an excellent selectivity since phospholipid (PL) reverse micelles formed in the system were rejected almost completely due to low solubility probably aided synergistically by size exclusion. Diafiltration achieved greater oil removal from lecithin as reflected in terms of higher AI and PL contents in the deoiled lecithin. In discontinuous diafiltration, the PL content increased from 33.3 to 85.5% in rice bran lecithin (150% dilution to feed) and 56.6 to 85.7% in soy lecithin (200% dilution), respectively. The simulated continuous diafiltration run showed slightly greater PL content in soy lecithin (91.3%) compared to discontinuous diafiltration (89.7%) besides offering higher productivity. The membrane showed a color reduction of ~60% in soy lecithin but there was no improvement in rice bran lecithin due to the retention of degradation products. The proposed integrated membrane process with nonporous (deoiling) and nanofiltration (solvent recovery) membranes could be an attractive preposition besides being an acetone free process.     

Treatment of a textile effluent: application of a combination method involving adsorption and nanofiltration

A combination of adsorption and nanofiltration (NF) was adopted for the treatment of a textile dyehouse effluent containing a mixture of two reactive dyes. The effluent stream was first treated in a batch adsorption process with sawdust as an adsorbent to reduce the dye concentration of the effluent by about 83% for Dye 1 and 93% for Dye 2. The effluent from the adsorption unit was passed through an NF unit for the removal of the remaining small amount of dyes and to recover the associated chemicals (mainly salt) in the effluent stream. The dyes remaining after this step were less than 1 ppm. The percentage removal of COD was greater than 99%, and the salt recovery was on the order of 90%. Equilibrium studies were carried out with synthetic solutions of the dyes (both single component as well as two-component systems) at room temperature. The adsorption rates were studied in detail using varying amounts of the adsorbent. NF of the effluent was performed in a cross-flow system using a 400 molecular weight cut-off membrane. A detailed study was carried out to observe the effect of the process parameters, namely applied pressure and bulk velocity on the process outputs such as dye rejection, COD removal, permeate flux and salt recovery. Finally, direct NF of the effluent (with the original high concentration) was undertaken, and the performance of the process was compared with the combination method. The permeate flux for the proposed combined method was found to be about twice that for the direct NF method. The dye rejection improved significantly compared to adsorption.