陶瓷膜超滤纯化赤藓糖醇发酵液的工艺研究

采用截留分子量为30万u的陶瓷超滤膜纯化赤藓糖醇发酵液,考察运行时间、跨膜压差(TMP)、料液折光浓度和操作温度对膜通量的影响,分析各条件下稳定通量的变化规律.研究表明:实验设备运行1h后膜管通量开始稳定,当跨膜压差为0.3MPa、料液折光浓度为15％、操作温度为50℃时,稳定通量维持在75L/(h· m2),制得的赤藓糖醇液的色谱纯度为80％.     

陶瓷膜超滤纯化褐藻酸钠及其分子量测定

采用截留分子量为10000u的陶瓷超滤膜纯化褐藻酸钠溶液,考察运行时间、跨膜压差(TMP)、料液稀释倍数和操作温度对膜通量的影响,分析各条件下稳定通量的变化规律。研究表明:实验设备运行1h后膜管通量开始稳定,当跨膜压差为0.08MPa、料液稀释倍数为3倍、操作温度50℃时,稳定通量维持在75L/(h·m2)。通过超滤纯化制得的褐藻酸钠的纯度为96.25%,圆二色谱法测得β-D-甘露糖醛酸和α-L-古罗糖醛酸量的比值为1.4845,高效凝胶渗透色谱法测得平均相对分子量分别为2.13×106u,并对所得褐藻酸钠的光谱学性质进行了研究。     

无机陶瓷膜浓缩APMP制浆废液的研究

采用孔径为0.2μm、50 nm和20 nm的无机陶瓷膜过滤APMP制浆废液,通过对膜孔径、跨膜压差(TMP)、体积浓缩因子(VCF)3个因素进行分析,得到最佳工艺条件:陶瓷膜孔径20 nm,跨膜压差0.2 MPa,操作温度80℃,体积浓缩因子7.6,在此条件下废液通量为891 L·(h·m2·MPa)-1,浓缩液总固形物(TS)浓度从22.57 g·L-1升高到58.38 g·L-1。     

柚子皮中果胶的提取工艺优化

目的优化酸提醇沉法提取柚子皮中果胶的工艺。方法以液料比、溶液p H值、提取温度、提取时间为实验因素,果胶提取率为评价指标,进行L_9(3~4)正交试验设计,3水平4因素响应面实验设计,最后对提取的果胶进行理化性质分析。结果 2种方法相比较,实验因素对评价指标的影响权重基本一致,即提取温度溶液p H液料比提取时间,但最佳工艺和果胶提取率略有不同。正交试验确定的最佳工艺条件为液料比25:1(m L:g)、溶液p H 2.0、提取时间100 min、温度80℃;响应面实验确定的最佳工艺条件为:液料比26:1(m L:g),溶液p H1.9,提取时间106 min,提取温度77℃。连续6组实验取平均值为21.31%,响应面提取率比正交提高了6.6%。结论本实验建立的响应面模型可用于实际柚子皮酸提果胶过程预测,为柚子皮生产高值化利用和果胶的开发提供依据。     

不锈钢膜超滤澄清甲壳素碱煮废水的研究

不锈钢膜澄清甲壳素碱煮废水,为掌握膜通量衰减规律以及膜对料液中非碱固形物、悬浮固形物的截留规律,用5批次不同浓度的蟹壳碱煮液,全循环模式下进行变跨膜压差(TMP)实验,发现TMP小于3.1 bar时为压差控制区,大于3.1 bar时为浓差极化阻力控制区.在压差控制区内,膜通量随TMP增大而增大.TMP控制在3.1 bar,料液温度控制在70℃,平均膜通量随料液初始浓度减小而增大.分别为108.15、136.65、171.48、187.09、228.57 L·m-2·h-1,非碱固形物的截留率随时间的增加而增大.滤液的悬浮固形物含量均在0.01%以下,证明不锈钢超滤膜技术可以高效澄清甲壳碱煮液,截留全部悬浮固形物.     

正交试验优化银条多糖超滤浓缩工艺

以膜通量为指标,首先探讨操作压力、超滤温度和料液pH值3个工艺参数对超滤浓缩银条多糖的影响,在此基础上通过正交试验确定超滤浓缩的最佳工艺参数,最后通过测定清洗前后膜的水通量变化确定最佳的超滤膜清洗方法。结果表明超滤浓缩效果优于常规浓缩的效果,超滤浓缩银条多糖的最佳工艺参数为操作压力0.35MPa、操作温度30℃、料液pH6.5;最佳膜清洗方法为用40℃、pH8.5的NaOH溶液清洗0.5h,此时清洗前后纯水的膜通量相差9.00L/(m2.h)。     

响应面优化脐橙皮中果胶的提取工艺及理化性质分析

采用单因素、正交分析法分析果胶提取工艺,再根据Box-Behnken实验设计原理,选取液料比、提取温度、提取时间、提取液p H值进行4个因素对酸提醇沉淀工艺进行正交设计和响应面优化,最后对果胶理化性质进行分析。结果表明:正交设计和响应面法两种方法,两种方法在分析各因素脐橙皮中果胶提取率的影响上所得结果基本一致,即液料比p H提取温度提取时间,正交试验确定的最佳工艺为:液料比20∶1(m L/g)、p H0.8、提取时间100 min、温度80℃;响应面试验确定的最佳工艺为:液料比21∶1(m L/g),提取液p H0.7,提取时间102 min,提取温度81℃。通过二者确定的最佳条件进行验证试验,结果表明按照响应面法分析的最佳工艺条件所得的提取率高于正交试验5.42%。因此,脐橙皮中果胶提取的最佳工艺以响应面法为准,该条件下脐橙皮中果胶得率为23.52%。提取的果胶各项理化指标符合国标要求,文章为生产加工脐橙皮果胶提供了低廉、高效、简单的提取方法。     

辣椒粕果胶提取工艺的优化

目的:研究辣椒粕果胶提取、脱色最优工艺。方法:以辣椒粕为原料,采用酸水超声提取果胶,以果胶得率为考察指标,在单因素试验的基础上,采用响应面设计,研究超声功率、超声时间、料液比对辣椒粕果胶提取率的影响;采用单因素实验,对果胶脱色工艺进行了优化。结果:优化辣椒果胶的提取工艺,得到最优工艺为:超声功率为450W,超声时间为35min,料液比为1∶21,优化的脱色条件为:活性炭用量0.6g/100m L、双氧水用量4m L/100m L、脱色温度70℃、脱色时间70min。按该工艺进行试验所得辣椒果胶得率为16.85%,与预测值基本一致,且产品符合QB2484-2000中规定的质量标准,通过验证实验也证实了利用Box-Behnken响应面法优选的辣椒果胶提取工艺稳定可行。     

蛤肉预煮液反渗透膜浓缩工艺研究

以蛤肉预煮液为原料,经非热力浓缩--反渗透膜(RO膜)处理达到理想料液浓缩度.通过选择RO膜种类以及对操作压力、操作温度和进料流速三因素的L9(34)正交试验,确定二级反渗透浓缩的最佳工艺条件.结果表明:选用三醋酸纤维素RO膜效果最好;二级RO膜浓缩的最佳工艺条件为压力3.5 MPa、温度38℃、流速1.5 m/s;浓缩后料液浓缩度可达32.5°Bx.     

苹果果胶膜法分离工艺研究

对苹果果胶超滤法分离条件和不同分子量的果胶与其性质的关系进行研究,采用5种不同截流分子量(MWCO)的超滤膜分离苹果果胶.结果表明:在跨膜压差为0.08MPa,料液浓度为1g/L,室温下,不同分子量的果肢获得了良好的分离.分子量与其理化性质有着对应的关系,分子量越大,其半乳糖醛酸含量和酯化度均越高,透光率减小.同时.超滤时果胶液的脱色有良好作用.本实验为工业上果胶的纯化、分离提供理论依据.     

Pretreatment of aqueous pectin solution by cross‐flow microfiltration: analysis of operational parameters,degree of concentration and pectin losses

Obtaining pectin through traditional precipitation processes requires a large amount of organic solvent. A reduction in solvent consumption may be achieved by incorporating a cross‐flow microfiltration step in which the extraction solution is removed and pectin is concentrated. In this study, we used α‐alumina tubular membrane (0.44 μm) in two operation modes: total recycle mode to evaluate the effect of temperature, initial concentration of pectin and transmembrane pressure on the permeate flux and pectin coefficient rejection; and batch mode to evaluate the degree of concentration and loss of pectin. It was observed that pectin coefficient rejection varied from 93.4 ± 0.7% to 97.8 ± 0.3%, and a maximum permeate flux of 238.69 ± 6.48 kg m^?2 h^?1 with 0.12 MPa at 50 °C and 1.0 g kg^?1. Using the optimum conditions, the flux observed at the end of the process was 32.8% lower than the flux in the total recycle mode, enabling a final concentration of pectin in the retained solution of 61.04 ± 0.87% with an average pectin loss in the permeate stream of 8.18%.     

聚砜超滤膜在菜籽油脱胶中的应用

研究了聚砜超滤膜在菜籽油脱胶中的应用,讨论了操作时间(10 ～60 min),菜籽油-正己烷混合液中菜籽油质量分数( 10％～ 50％),操作压力(0.05～0.20 MPa)和操作温度(10～30℃)对脱胶效果的影响.结果表明:混合液渗透通量随操作时间的延长和混合液中菜籽油质量分数的提高而降低,但膜对磷脂的截留率表现出增大的趋势;渗透通量随操作压力和操作温度的升高而增大,但操作压力和操作温度对磷脂截留率影响很小.在实验条件下,聚砜超滤膜对30％菜籽油-正己烷混合液的渗透通量为8 ～33 kg/(m2 ·h),磷脂截留率为60％ ～ 80％:对菜籽油的渗透通量为0.2～3.5 kg/(m2·h),磷脂截留率达到91％ ～93％.     

陶瓷膜处理乙醇发酵废水的工艺条件研究

发酵法生产乙醇的过程中产生大量废水,文中采用陶瓷膜处理乙醇发酵废水,考察了膜孔径、料液性质以及操作条件对过滤过程的影响。结果表明,陶瓷膜过滤乙醇发酵废水有较好的效果,化学需氧量(COD)去除率达80%,固体悬浮物(SS)截留率在99%以上。确定了孔径为200nm的膜管在pH值为8.0,错流速度为5m/s,温度为50℃,操作压力0.15MPa条件下操作,膜通量大于700L/(m2·h)。     

超滤浓缩微生物胞外多糖PS-9415发酵液的研究

本文采用了截留分子量为70，000的平板超滤膜对微生物胞外多糖PS－9415的发酵液进行了超滤浓缩的研究。膜的透过通量受料液浓度，搅拌速度，操作压力等因素的影响。其中，降低料液浓度，增加搅拌，提高压差可以增加膜的透过通量。0．5％的多糖在室温,0.15MPa下超滤108min可浓缩2倍。     

Optimization and Modeling of Apple Juice Cross-flow Microfiltration with a Ceramic Membrane

The performance of a 0.2 μm ceramic membrane for clarification of depectinized apple juice was studied. The results showed that the flux was higher at high feed velocities (14.6 m/seC) and high temperatures (50°C), and the transmembrane pressure was a positive factor only at high temperatures. The juice flux at optimal conditions was between 400–500 kg/hr.m². Filtration of juice with pectin resulted in flux decreases of 40–50% compared to deoectinized juice. Periodic back-flushing during processing at optimal conditions, i.e., high temperature, high feed velocity and low pressure, did not significantly increase the juice flux.     

中试超滤系统浓缩分离南瓜多糖

为进一步推动南瓜作物的深加工及高附加值生产,采用自行研制的全自动超滤浓缩中试系统对南瓜多糖溶液进行超滤浓缩,分别考察超滤温度、超滤时间、超滤压力及进料液浓度对超滤膜通量的影响,发现膜通量随温度和压力的增加而增大,随超滤时间和料液浓度的增加而减小。对超滤膜的污染情况也进行研究,发现随膜使用时间的延长,超滤过程将造成难以恢复的膜污染。     

柚皮果胶提取液的超滤膜法浓缩与脱色

采用超滤膜法对柚皮果胶提取液进行浓缩和脱色.考察膜截留分子量、跨膜压力、温度等对膜通量和脱色率的影响,并对污染后的膜清洗进行研究.结果表明:使用陶瓷超滤膜对柚皮果胶提取液进行浓缩与脱色是可行的,其适宜工作条件为:膜截留分子量为300000u,跨膜压力为0.14MPa,温度室温,采用间断全过滤的操作方式.超滤过程中受污染的膜采用氢氧化钠ω(NaOH)=2%与盐酸ω(HCl)=2%组合洗涤.膜通量恢复较好.     

CONSEQUENCES of FOULING and MACROMOLECULE ADSORPTION ONTO ULTRAFILTRATION MEMBRANE FOR PINEAPPLE JUICE PROCESSING

Pineapple juice samples were ultrafiltrated using a polysulfone 10,000 molecular weight cut-off (MWCO) membrane. However, to facilitate operations, the ultrafiltration experiments were preceeded by fractionation of juice samples using sequentially Microfiltration/Diafiltration and Ultrafiltration/Diafiltration with 8 μm; 0.4 μm; 0.2 μm and 0.1 μm membranes, using three specific experimental procedures. the 10,000 MWCO membrane was cleansed using a 40°C IN NaOH solution for a minimum of 30 min, to restore optimal membrane water permeation flux. the effects of selective fractionation processes, pretreatments (using antifoaming agent, hemicellulase, and ammonium sulfate saturation), on permeation rates, concentration levels, protein rejection and protein yields were determined. Water permeation fluxes, measured before and after each UF operation showed a dramatic flux drop from 313 L/hm² to 91 L/hm² within seven successive 10,000 MWCO membrane experiments. This occurred inspite of suitable membrane washing conditions, pretreatments and selective fractionation processing of samples. the modification, mainly due to fouling, of the integrity of the 10,000 MWCO membrane relative to concentration level was investigated.     

Cross-flow Microfiltration with Gas Backwash of Apple Juice

Cross-flow microfiltration (MF) was applied for clarification of commercially pressed depectinized apple juices and pectin containing artificial apple juice suspensions under continuous low pressure inlet conditions (35 kPa - 209 kPa). Periodic gas backwash (air or N₂) removed solids from exteriors of 0.2 μm cut-off hollow fiber polypropylene membranes. Flux and nephelos turbidity units (NTU) of filtrates for both commercial juices and artificial juices were evaluated. Commercial juices after vacuum filtration and MF had 100–110 L/m²/hr flux during 2 hr operation. Low pectin (1%) artificial juices had ～70 L/m²/hr flux during 1.5 hr. NTUs of filtrates from all treatments were <0.69. All filtrates were commercially sterile.