聚丙烯酸钠络合-超滤分离钯(Ⅱ)

以聚丙烯酸钠(PAAS)为络合剂,研究钯(Ⅱ)的络合-超滤行为.考察聚合物/金属质量比(rp/m)、pH、膜两侧压差(△p)对膜通量(J)和钯截留系数(RPd)的影响,发现J不随rp/m变化,随pH增大而增大,随△p增大呈线性递增:RPd随rp/m或pH增大而增大,与△p无关.控制rp/m=2和pH=6,PAAS-钯(...     

聚电解质强化超滤技术处理钨(Ⅵ)

以聚季铵盐-6(PQ6)强化超滤技术处理钨(Ⅵ),考察了渗滤对PQ6预处理的影响.结果表明,随渗滤体积增加PQ6截留系数逐渐增大到1,PQ6损失率为12.7%,膜通量(J)轻微增大.研究了pQ6与金属质量比r和pH值对钨截留系数(Rw)和J的影响,当r从1增大到3,Rw线性递增,此后趋于1,PQ6对钨(Ⅵ)的络合容量[PQ6/钨(Ⅵ)]为3.0 mg/mg;当pH值从3增大到9时,Rw基本不变:J随r增大略有下降,但不随pH值变化.在r=3和pH=7的条件下,当体积浓缩因子为16时,J下降15.2%,Rw接近1,截留液钨浓度从20 mg/L增大到317.5 mg/L渗透液钨浓度约为0.04 mg/L,钨(Ⅵ)被有效浓缩.     

聚季铵盐强化超滤处理铬(VI)

以聚季铵盐-22(PQ22)为络合剂,研究Cr(VI)的强化超滤行为,考察聚电解质/金属质量比、pH值及外加盐对PQ22-Cr(VI)络合体系截留系数和膜通量的影响,并研究了络合体系的浓缩、解络合和洗涤过程. 结果表明,当聚电解质/金属质量比为80及pH=9时,Cr(VI)截留系数大于0.9;外加Cl-, NO3-和SO42-使Cr(VI)截留系数降低,且SO42-比NO3-和Cl-的影响更大;控制聚电解质/金属质量比为80及pH=9,当浓缩因子为20时,Cr(VI)浓度从初始的5 mg/L浓缩至82.6 mg/L;对浓缩液解络合,控制Cl-浓度为0.15 mol/L,解络合率为71.1%,以Cl-溶液对解络合液进行洗涤,Cr(VI)洗脱率可达95.9%. 聚季铵盐-22可循环使用.     

聚合物强化超滤过程处理含Hg~(2+)废水

研究聚丙烯酸钠(PAASS)与Hg2+络合反应动力学,当PAASS大量过剩及pH值恒为5时,络合反应达到平衡时间为25 m in,反应行为可用拟一级速率方程描述。测定PAASS对Hg2+络合能力,pH=5时每mg PAASS络合容量为1.0 mg。考察pH值、盐浓度和竞争络合剂对Hg2+截留系数的影响,可得:pH=5及负载比LR=1时适宜截留Hg2+;当C l-和SO42-浓度增大时,Hg2+截留系数逐渐降低;酒石酸钠和三乙醇胺不干扰PAASS与Hg2+的络合。进一步研究超滤浓缩行为,结果表明:当pH=5,PAASS及Hg2+初始质量浓度均为100 mg/L时,原料液浓缩15倍,膜通量仅衰减15.0%,浓缩液及渗透液汞质量浓度分别为1499.6,0.03 mg/L。     

聚季铵盐强化超滤分离铼(Ⅶ)

以聚季铵盐-6强化超滤技术分离铼(Ⅶ),考察聚季铵盐与金属质量比w、pH值、外加盐、运行时间和操作压力对铼截留系数R和膜通量J的影响,结果表明:当w从1增大到7时,R迅速递增,w达到7时的R为0.995,继续增大w,R逐渐趋于1;J随w增大略有下降;当pH值从3增大到8时,R和J几乎不随pH值变化而变化;随着外加盐质量浓度递增,R逐渐递减至不变,J略有下降;随着运行时间延长,R基本不变,J轻微衰减;当操作压力增大时,R不变,J呈线性快速递增。研究铼(Ⅶ)-聚季铵盐体系的超滤浓缩行为,控制w=7,pH=7,温度25℃和压力60 kPa,当体积浓缩因子为40时,J仅衰减20.1%,在浓缩过程中R均接近1,截留液铼质量浓度从5 mg/L增大到198.3 mg/L,渗透液铼质量浓度约为0.04 mg/L,铼被有效浓缩。     

PEI络合-超滤耦合过程分离铜和锌废水的研究

水溶性聚合物络合-超滤耦合过程是一种新型、环保处理工业废水的方法。它不但能够实现废水回用和重金属浓缩,而且能有效地分离二元重金属混合液。选取高效、环保的络合水处理剂聚乙烯亚胺(PEI),对含铜、锌的二元重金属废水进行络合-超滤耦合过程研究,探讨了pH值、装载量比L、离子强度等对超滤过程的影响;pH=7时,PEI对Zn2 和Cu2 的络合容量分别为KCu=0.10mgCu2 /mgPEI,KZn=0.06mgZn2 /mg PEI。随PEI浓度增加,超滤膜通量J=35～45L/(m2·h)。     

络合-超滤耦合技术处理Cd^（2＋）模拟废水的研究

研究聚丙烯酸钠PAASS与模拟废水中Cd2 络合反应动力学,结果表明:当pH为6、Cd2 浓度为10 mg·L-1和PAASS浓度为5000 mg·L-1时,络合反应符合拟一级速率方程.考察负载比对Cd2 截留系数R的影响,可得PAASS络合容量为0.033 g Cd·(g PAASS)-1.考察pH和竞争络合剂对R的影响,发现当pH从5增大到6时,R迅速增大;竞争络合剂三乙醇胺或酒石酸钠使R下降.研究络合体系超滤浓缩行为,结果表明体积浓缩因子为10时,膜通量仅下降14.6%,R值大约为1;浓缩液用于解离研究,控制解离pH为2.5,可得:当截留液镉浓度为99.6 mg·L-1时,渗透液镉浓度可达93.1 mg·L-1,对应络合物解离效率为93.5%;解离液用于超滤洗涤,当洗涤液体积为原料液体积4倍时,截留液镉浓度从洗涤前99.6 mg·L-1降低至洗涤结束时3.87 mg·L-1,镉洗脱率为96.1%,洗涤后聚电解质纯度高.     

聚合物辅助陶瓷膜处理模拟含油低放废水

利用陶瓷膜,以相对分子质量为300 000、1000000、5 000 000的聚丙烯酸钠为络合剂处理模拟含油低放废水.研究了络合比、pH、体积浓缩因子等因素对超滤过程的影响.结果表明:在各种条件下,陶瓷膜对油及Fe3+的截留率均接近100%;在适当条件下,对Mn2+、Ni2+、Co2+的最大截留率分别接近100%、9...     

电沉积处理络合-超滤过程中含镍浓缩液

在络合-超滤处理含镍废水并得到镍离子质量浓度为418 mg/L浓缩液的基础上,考察了电沉积法处理含镍浓缩液过程中电流密度、初始pH、电解时间、温度、极距、搅拌等参数对电流效率和镍回收率的影响。结果表明:当电流密度、电解时间增加时,电流效率随之下降,而镍回收率增大;当pH、极距增大时,电流效率和镍回收率均先增大后减小;温度升高、低速搅拌均可提高电流密度与镍回收率。在电流密度为3.5 m A/cm~2,pH=4,温度为50℃,电解时间为130 min,极距为10 cm并加入低速搅拌的最优操作条件下,电流效率最高可达42%,镍回收率可达52%,并探讨了电沉积机理。     

无机陶瓷膜在超细分子筛固液分离上的实验研究

采用无机陶瓷膜分离技术,可以实现超细分子筛在浓缩和洗涤过滤过程中的充分截留。研究表明,采用平均孔径为0.2μm的无机陶瓷膜,在常温、膜面流速为6m/s、分子筛浆液固含量小于40%的条件下,用于分子筛固液分离时,平均渗透通量在200L/(m2.h)以上,滤液中悬浮物含量低于40mg/L。     

聚季铵盐辅助络合-超滤提取钨(Ⅵ)(英文)

Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (Ⅵ) before ultrafiltration. Tungsten (Ⅵ)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR), pH and chloride ion concentration on permeate flux (J) and tungsten rejection coefficient (R) were investigated. The integration of four experiments including concentration, decomplexation, diafiltration and reuse of regenerated polymer was carried out. In the process of concentration, J declines slowly and R is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mg·L-1 . The decomplexation percentage of tungsten (Ⅵ)-PQ6 complex reaches 56.1%. In the diafiltration process, tungsten (Ⅵ) can be extracted effectively by using 50 mg·L-1 chloride ion solution, and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (Ⅵ) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6, and the recovery percentage of binding capacity is higher than 90%.     

Experimental studies on extraction of cobalt ions from dilute aqueous solutions by using complexation-ultrafiltration process

The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid) sodium salt (PAASS). Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process. The kinetics of complexation reaction was studied for PAASS with Co²⁺. Results showed that, under a large excess of PAASS, it takes 65, 55 and 40 min at pH 5, 6 and 7, respectively, to get the equilibrium of complexation. The reaction kinetics can be described by a pseudo-first-order equation. Then, the effects of various parameters on the extraction of Co²⁺ were examined in detail. Results indicated that loading ratio, pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R. Furthermore, a concentration experiment was carried out at pH 7. With increasing volume concentration factor, membrane flux declines slowly, and R value is always about 1. The concentrated retentate was used further for a decomplexation experiment. The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%. After the decomplexation step, a diafiltration experiment was performed at pH 2.5. Cobalt ions can be extracted satisfactorily from the retentate, and a purified PAASS is obtained.     

Recovery and purification of lactose from whey

One of the main problems associated with the manufacturing of cheese is the production of whey, which causes environmental pollution due to its high concentration of dissolved organic substances, mostly proteins, fat and lactose. The search for economically viable and appropriate alternative uses of whey proteins and lactose is of fundamental importance. This work investigated four integrated processes, incorporating microfiltration, ultrafiltration, ion exchange, reverse osmosis and spray-drying, for the separation and purification of lactose from whey. The recovery and the purity of the final lactose product recovered were evaluated. It was shown that the process comprising of microfiltration (nominal pore size 0.2 μm), ultrafiltration UF3 (molecular weight cut-off 5 kDa), ion exchange and reverse osmosis, a lactose purity of 99.8% (including 4.2% of galactose/glucose) and an overall lactose recovery of 74% were obtained. The lactose left over in the retentate and trapped in the membrane modules and ion exchange columns could be further recovered to improve the overall recovery.     

Fenton氧化-沸石吸附联合处理化学镀镍废水

以Ni~(2+)、总磷和氨氮为考察对象,采用Fenton氧化和沸石吸附联合处理化学镀镍废水。探讨了Fenton破络及协同氧化非正磷酸盐时,H_2O_2的质量浓度、m(Fe~(2+))∶m(H_2O_2)、初始pH值对Ni~(2+)和总磷去除率的影响。另外,研究了沸石吸附氨氮时,沸石量、吸附时间、吸附pH值对氨氮去除率的影响。结果表明:当H_2O_2的质量浓度为6.66g/L、m(Fe~(2+))∶m(H_2O_2)为0.06、初始pH值为3时,破络完全,非正磷酸盐转化率为99.45%;同时,Ni~(2+)和总磷的去除率分别达到99.72%和91.88%。当沸石量为8g/100mL、pH值为7、反应时间为60min时,氨氮的去除率为86.30%。     

Experimental studies on extraction of cobalt ions from dilute aqueous solutions by using complexation-ultrafiltration process

The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid) sodium salt (PAASS). Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process. The kinetics of complexation reaction was studied for PAASS with Co²⁺. Results showed that, under a large excess of PAASS, it takes 65, 55 and 40 min at pH 5, 6 and 7, respectively, to get the equilibrium of complexation. The reaction kinetics can be described by a pseudo-first-order equation. Then, the effects of various parameters on the extraction of Co²⁺ were examined in detail. Results indicated that loading ratio, pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R. Furthermore, a concentration experiment was carried out at pH 7. With increasing volume concentration factor, membrane flux declines slowly, and R value is always about 1. The concentrated retentate was used further for a decomplexation experiment. The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%. After the decomplexation step, a diafiltration experiment was performed at pH 2.5. Cobalt ions can be extracted satisfactorily from the retentate, and a purified PAASS is obtained.     

Application of Polyelectrolyte‐Enhanced Ultrafiltration for Rhenium Recovery from Aqueous Solutions

Polyelectrolyte‐enhanced ultrafiltration was investigated for rhenium(VII) recovery from aqueous solutions by using polyquaternium‐6 (PQ6) as a complexing agent. The effects of the operating parameters on the permeate flux (J) and the rhenium rejection coefficient (R) were studied. In the process of concentration, J declines slowly and R is about 1. The concentrated solution was used for the decomplexation. It takes 10 min to achieve the decomplexation equilibrium at a chloride ion concentration of 100 mg L^–1. The decomplexation percentage reaches 45.6 %. In the diafiltration process, rhenium is extracted effectively, and the purification of the regenerated PQ6 is satisfactory. The regenerated PQ6 was used to bind rhenium(VII). The binding capacity of the regenerated PQ6 is close to that of fresh PQ6.     

Concentration of cupric and nickel ions by complexation-ultrafiltration. Synergic effect of succinic acid

In ultrafiltration, high rejection of small ion species can be achieved by complexing these species with a suitable macroligand.We have studied the concentration of cupric or/and nickel ions by ultrafiltration, through the DDS GR8 membrane, using polyethylenimine as a basic macroligand. The rejections of the metallic ions increased with the pH and the concentration of the polymeric ligand as expected. The addition of succinic acid (a molecular acidic chelating) to the mixtures allowed an improvement of the retentions of these ions at all pHs studied. This indicates that positive synergic effect was obtained by the formation of a mixed complex base-metal-acid.     

Recovery of metals and complexant in wastewater by shear induced dissociation coupling with ultrafiltration

Heavy metals (Pb (II), Hg (II), and Cd (II)) in ore dressing wastewater (ODW) were selectively separated by shear-induced dissociation coupling with ultrafiltration (SID-UF) using polyacrylic acid sodium (PAAS) as complexant. Metals (Pb (II), Hg (II), and Cd (II)) were complexed with PAAS and rejected by ultrafiltration membrane at first. The effects of pH and P/M (mass ratio of polymer to metal ions) on the rejection were investigated and the suitable pH and P/M were obtained, at which the rejection arrived at almost 100%. For the recovery of metals and polymer complexant from the retained, the shear stabilities of PAA-metal (PAA-M) complexes were studied, and the critical shear rates of PAA-Pb, PAA-Hg, and PAA-Cd complexes at pH 7.0 were 2.72 × 10,⁵ 2.42 × 10⁵ and 2.01 × 10⁵ s⁻¹, respectively. According to the difference of the critical shear rates of the PAA-M complexes, SID-UF was used to recover Pb (II), Hg (II), Cd (II) and PAAS. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48854.     

结晶器铜管镀硬铬脱脂废液的处理

以某表面处理公司的结晶器铜管镀硬铬脱脂废液为研究对象,先采用酸化法对废液中的配位铜离子进行破络处理,并通过调节pH使之沉淀析出,再采用Fenton试剂法降低废液的化学需氧量(COD)。研究了破络过程中FeSO4·7H2O的质量浓度和处理时间对破络效果的影响,以及降低COD过程中Fenton试剂的组成、处理时间和pH对废液COD的影响。脱脂废液处理的最佳工艺条件为:破络──FeSO4·7H2O12g/L,2h;降低COD──Fenton试剂为1.5g/LFeSO4·7H2O+4.5mL/LH2O2,pH=6.00,9h。在最佳工艺条件下处理过的脱脂废液澄清、透明,总铜含量满足GB21900-2008的排放要求,COD接近GB21900-2008的排放要求。