中空纤维更新液膜技术处理含铬废水

以磷酸三丁酯(TBP,质量分数为40%)/煤油为萃取剂、氢氧化钠溶液为反萃剂,采用一种新型的液膜技术———中空纤维更新液膜(HFRLM)技术处理含铬废水。研究了HFRLM技术对废水中Cr(Ⅵ)的去除与浓缩效果。结果表明,中空纤维更新液膜技术可同时实现废水中Cr(VI)的分离与富集。处理后,废水中Cr(VI)含量小于0.5 mg/L,Cr(VI)的去除率达99.8%,达到国家排放标准;富集液中Cr(VI)浓度高达2 500 mg/L。该项技术在含铬废水的处理方面表现出良好的应用前景。     

中空纤维支撑液膜法提取林可霉素的研究

研究了反萃相预分散中空纤维支撑液膜技术提取林可霉素的传质过程,实现了林可霉素的萃取和反萃过程的耦合。研究了萃取剂(正辛醇)体积分数、林可霉素质量浓度、原料液pH对分配系数的影响,膜组件操作过程中管程流量、壳程流量对总传质系数的影响,并得到最佳操作条件,建立了数学模型。结果表明,正辛醇体积分数为80%、林可霉素质量浓度为5.5 g/L、原料液pH=11时分配系数最大。膜组件最佳操作条件,原料液∶萃取相=500∶500(mL/min)。利用传质模型求得原料侧水相传质阻力1/kW、跨膜传质阻力1/kM、反萃侧水相传质阻力1/kS在总传质阻力所占比例分别为21%、74%、6%,其中跨膜传质阻力是传质阻力主要部分。     

用磷酸三丁酯萃取分离硫酸铵母液中的HCN

研究了磷酸三丁酯(TBP)-磺化煤油体系从重庆某企业甘氨酸生产副产物硫酸铵母液中萃取分离HCN的工艺,考察了萃取体系、TBP体积分数、母液初始pH值、相比(Vorg∶Vaq)对萃取HCN的影响以及氢氧化钠浓度、相比(Vaq∶Vorg)和平衡pH值对HCN反萃的影响。结果表明:选用TBP作为萃取剂能够对硫酸铵母液中的HCN进行快速有效的萃取;TBP体积分数、母液初始pH值及相比对HCN萃取率影响显著;以含体积分数35%TBP的有机相作萃取剂,在相比(Vorg∶Vaq)为2∶1的条件下,pH值为2.92的含氰1.71 g/L的硫酸铵母液经3级错流萃取,萃余液中含氰低于0.5 mg/L,氰的萃取率接近100%;在相比(Vaq∶Vorg)为1∶1条件下,以0.6 mol/L的氢氧化钠为反萃液,控制反萃液平衡pH值大于13.0,氰的单级反萃率大于96%;含氰0.78 g/L的有机相在相比为1∶1条件下,经过2级错流反萃,氰基本上被反萃完全,贫有机相不经过处理可循环使用。     

萃取置换法预处理氟苯生产废水的实验研究

以磷酸三丁酯(TBP)为萃取剂、NaOH水溶液为反萃剂,采用萃取置换法回收处理氟苯生产废水中的苯酚。研究了萃取剂浓度、萃取时间、pH值及相比对萃取率的影响和相比、反萃时间及NaOH溶液浓度对反萃率的影响。经3级萃取和2级反萃,苯酚的回收率达98%,废水中苯酚含量可降至19.7 mg/L。萃取置换法操作简单,费用低廉,易于工业化。     

中空纤维更新液膜技术处理模拟含铜电镀废水

以10%(体积分数)LIX984N/煤油为液膜相,2 mol/L硫酸溶液为反萃相,研究了中空纤维更新液膜(HFRLM)技术对模拟电镀废水中二价铜离子的去除及浓缩效果,并讨论了停留时间对二价铜离子去除率的影响.结果表明,中空纤维更新液膜技术可同时实现废水中二价铜离子的分离与富集.经7级处理后,废水中二价铜离子的含量低于1.0 mg/L,二价铜离子的去除率为99.0%,达到国家排放标准;富集液中二价铜离子的浓度达1700 mg/L,富集因子为25.中空纤维更新液膜技术在含铜废水处理方面具有广阔的应用前景.     

萃取置换法回收处理氟苯生产废水中的苯酚

以磷酸三丁酯(TBP)为萃取剂、NaOH水溶液为反萃剂,采用萃取置换法回收处理氟苯生产废水中的苯酚.研究了萃取剂浓度、萃取时间、pH值及相比对萃取率的影响和相比、反萃时间及NaOH溶液浓度对反萃率的影响.经3级萃取和2级反萃取,苯酚的回收率达98%,废水中苯酚含量可降至19.7 mg/L.萃取置换法操作简单,费用低廉,易于工业化.     

乳状液膜法萃取废水中氰化物的特性

针对氰化废水的特点,以三正辛胺（TOA）为载体、煤油为膜溶剂、液体石蜡为膜助剂、NaOH水溶液为内水相,采用乳状液膜技术处理工业废水中的氰化物。重点考察了表面活性剂用量、流动载体用量、内相液NaOH浓度等因素对氰化物萃取率的影响规律。研究结果表明：当TOA体积分数为2%、表面活性剂Span-80体积分数为3%、液体石蜡体积分数为1%、内水相NaOH质量分数为2%、油内比为1︰1、乳水比为1︰7、萃取时间为15min时,氰化废水中氰化物的萃取率达到95%以上。在实验得出的最优条件下,考察最优条件对初始浓度不同的实际废水的适用范围,分别对初始浓度为322.23mg/L、483.35mg/L、644.46mg/L和966.70mg/L的氰化废水进行处理,可得该体系下处理氰化废水的较佳的浓度范围为300～500mg/L,氰化废水中氰化物的萃取率可达到95%以上。综上所述,乳状液膜法在工业上具有良好的应用前景。     

支撑液膜法制备头孢氨苄的研究

建立一个三相体系,实现对头孢氨苄的合成与分离。对支撑液膜及其传质机理进行了简要介绍。实验中,以Isopar L为萃取剂,甲基三辛基氯化铵(Aliquat 336)为载体,1-癸醇为载体助溶剂。萃取部分考察了进料相头孢氨苄的浓度、进料液pH、进料相和有机相体积比对萃取率的影响。反萃部分考察了反萃液pH对反萃率的影响,对比了几种反萃液的反萃效果,最终选择pH=9.0的D-苯甘氨酸甲酯盐酸盐(PGME)溶液作为反萃液。选择进料头孢氨苄浓度为20 mmol/L,进料液pH为9.0,进料相与有机相体积比为1∶1进行实验,得到头孢氨苄的最终收率为58.43%。     

乳状液膜系统稳定性的显微研究及Cr(VI)离子分离效率分析

采用毛细显微摄像技术,对乳状液膜系统的稳定性进行了微观研究并分析了稳定性对液膜分离效率的影响. 实验中将含重金属离子Cr(VI)的工业废水作为外水相,采用TBP-Span80-煤油体系作为油膜相,NaOH溶液作为内水相,制备了单个W1/O/W2型双重乳液颗粒系统,通过显微镜直观、实时地观察不同组成的双重乳液系统的稳定性,同时采用此乳状液膜体系对废水中的Cr(VI)进行了去除实验,将实验与机理研究相结合,通过研究pH值、表面活性剂、载体及内水相组成等对乳状液膜稳定性和Cr(VI)提取率的影响,阐明了液膜稳定性与液膜法去除Cr(VI)的分离效率之间的内在联系. 实验结果表明,在选择条件下,经过一次性处理10 min后,Cr(VI)的提取率可达99.3%以上,残余质量浓度降至0.5 mg/L,达到国家排放标准.     

磷酸三丁酯/煤油支撑液膜体系中苯酚的传质分离

研究了苯酚在以多孔聚丙烯平板膜(Celgard2500)为支撑体、磷酸三丁酯(TBP)为膜载体和煤油为膜溶剂的支撑液膜体系中的传质过程;用传统萃取法测定了TBP/煤油体系中苯酚络合物摩尔比为1∶1,同时得到25.0℃萃取平衡常数为96.72;考察了原料相pH值、初始质量浓度、膜二侧转速、载体浓度和反萃取相碱浓度对苯酚传质的影响,确定了该体系分离苯酚的最佳条件:原料相pH<9,苯酚初始质量浓度<1 000 mg/L,膜二侧转速>300 r/m in,载体浓度为0.55 mol/L,反萃取相碱浓度0.10 mol/L;根据双膜理论提出苯酚的传质动力学方程,采用直线斜率法计算了苯酚在TBP/煤油支撑液膜体系中的扩散层厚度和膜内扩散系数,计算结果表明动力学方程计算值能较好地与实验值吻合,平均相对误差在2%以内。     

离子交换法处理含Cr(Ⅵ)废水的研究

采用201×7强碱性阴离子交换树脂处理模拟含Cr(Ⅵ)废水,探讨了废水酸度、交换时间、浓度对Cr(Ⅵ)去除率的影响以及树脂再生所需的合适温度和再生剂浓度。结果表明,201×7强碱性阴离子交换树脂处理模拟含Cr(Ⅵ)废水,具有交换容量大、交换效果好、树脂再生条件较简单等优点。并对实际含铬废水进行了处理,废水中Cr(Ⅵ)的初始浓度为1 540 mg/L,处理量达52 BV(床体积)时,出水中Cr(Ⅵ)的浓度仍小于0.5 mg/L,达到国家排放标准。树脂交换容量约80 mg/g。用8%NaOH溶液,在50℃条件下进行再生效果较好,再生率大于95%,可实现树脂的重复使用。     

Use of bulk liquid membrane for the removal of chromium (VI) from aqueous acidic solution with tri-n-butyl phosphate as a carrier

Tri-n-butyl phosphate (TBP) was used as carrier for the transport of chromium (VI) through a hexane bulk liquid membrane. The transport efficiency of chromium (VI) by TBP was investigated under various experimental conditions such as pH of the feed phase (Cr (VI) solution), concentration of the receiving phase (NaOH solution), concentration of TBP in membrane, rate of stirring, effect of transport time, type of solvent, Cr (VI) concentration in feed phase, and effect of temperature. The transport efficiency increased with increasing carrier concentration from 7.5 × 10^− 2 to 2.25 × 10^− 1 mol/L. At high pH (donor phase) the transport rate of chromate ions decreased. At high stirring speed (300 rpm) the Cr (VI) transport from the feed phase to the strip phase was completed within 5 h at 27 °C. Under optimum conditions: donor phase 4.8 × 10^− 4 mol/L K₂Cr₂O₇ solution at pH 1.0 ± 0.1, acceptor phase 1.0 mol/L NaOH solution, membrane phase 2.25 × 10^− 1 mol/L, stirring speed 300 rpm, and temperature 27 °C, the flux rate was found to be 2.90 × 10^− 7 mol/m² s.     

Transport of Cr(VI) from HCl Media Using (PJMTH+Cl−) Ionic Liquid as Carrier by Advanced Membrane Extraction Processing

The transport of Cr(VI) from acidic media through pseudo-emulsion based membrane strip dispersion (PEMSD) containing the ionic liquid (PJMTH⁺Cl^?) as carrier in the form of a pseudo-emulsion with sodium hydroxide has been investigated. The ionic liquid was generated in situ by reaction of the primary amine Primene JMT and HCl. The transport of Cr(VI) is evaluated as a function of various experimental variables: stirring speed in the feed phase, concentration of Cr(VI) and HCl in the feed phase, carrier concentration, and organic diluents in pseudo-emulsion, and NaOH concentration in pseudo-emulsion as strippant. In PEMSD, pseudo-emulsion is an emulsion that is formed temporarily between the organic and the stripping solutions. Both solutions are separated when the stirring device is stopped. The value of the overall permeation coefficient obtained under standard experimental conditions was 3.1 × 10^?3 cm s^?1, whereas the transport process is controlled by diffusion of chromium species in the stagnant film of the feed phase. The performance of the system against other carriers (amines, quaternary phosphonium salt and quaternary ammonium salt) was also evaluated.     

Efficient transport and selective extraction of Cr(VI) from waste pickling solution of the stainless steel-cold rolled plate process using Aliquat 336 via HFSLM

The selective extraction of Cr(VI) from waste pickling solution of the stainless steel-cold rolled plate process by hydrophobic hollow fiber supported liquid membrane (HFSLM) was investigated. The effects of various parameters— types of organic extractants, i.e., metyl trioctylammonium chloride (Aliquat 336), tri-n-octylamine (TOA), tri-n-butyl phosphate (TBP) and the mixture of Aliquat 336 and TBP, concentration of the selected extractant, types of stripping solutions (NaCl and NaOH), pH and concentration of the selected stripping solution, and the operating temperature—were studied. The feed and stripping solutions flowed countercurrently. The results showed that the coexisting contamination in spent pickling solution of Fe(II) and Ni(II) ions had no significant effect on Cr(VI) extraction. Among the extractants used in this study, Aliquat 336 was a specific carrier to attain the highest percentage of Cr(VI) extraction. About 70% extraction was achieved by using 0.11 M Aliquat 336 and 0.5 M NaCl at pH 7. The percentage of stripping slightly increased when the concentration of NaCl increased. In addition, it was found that the operating temperature of 20, 30, 40, and 50 °C had almost no influence on the percentages of extraction and stripping of Cr(VI). The calculated diffusion energy of Cr(VI) extraction was 15.14 kJ/mol.     

皂化P204微乳液膜处理含锌废水的研究

研究以皂化P204为载体的微乳液膜配方及其稳定性.采用P204/Span80/煤油/NaOH微乳体系萃取废水中Zn^2＋,考察了P204与煤油和Span80的质量比、NaOH的浓度、乳水比、外水相pH值、油相重复使用次数等因素对Zn^2＋萃取率的影响.结果表明,当P204与煤油的质量比为1：2.5,P204与Span80的质量比为1：1,NaOH浓度为1.5mol/L,乳水比为1：4（体积比）,废水pH值为5.5时,萃取10min,P204/煤油/NaOH微乳液膜对Zn^2＋萃取率可达99.72%,P204/Span80/煤油/NaOH微乳液膜对Zn^2＋萃取率可达99.98%,微乳液膜不仅稳定性好、萃取效率高,而且工艺简单、膜相可自动破乳、油相可重复使用.     

Studies on the Recovery of Uranium from Phosphoric Acid Medium by D2EHPA/n-Dodecane Supported Liquid Membrane

Abstract

Present studies deal with the application of supported liquid membrane (SLM) technique for the separation of uranium (VI) from phosphoric acid medium using Di-2 ethyl hexyl phosphoric acid (D2EHPA)/n-dodecane as a carrier and ammonium carbonate as a receiving phase. The studies involve the investigation of process controlling parameters like feed acidity of phosphoric acid, carrier concentration, stripping agents, and the effect of thickness and the pore size of the membrane. The transport of uranium decreases with increase in the concentration of phosphoric acid in feed solution whereas it increases with increase in carrier concentration in supported liquid membrane. More than 90% uranium (VI) is recovered in 360 minutes using 0.5 M D2EHPA/dodecane as carrier and 0.5 M ammonium carbonate as stripping phase from the 0.001 M H₃PO₄ feed. Lower concentration of phosphoric acid and higher carrier concentration is found to be the most suitable condition for maximum transport of uranium (VI) from its lean sources like commercial phosphoric acid and analytical wastes generated from the analysis of uranium by Volumetric (Davis-Gray) method.     

乳化液膜法处理含铬废水的研究

采用span-80-煤油－NaOH液膜体系对含Cr(VI)废水的处理进行了研究，讨论了不同操作条件对Cr(VI)去除率的影响，得出了提取Cr(VI)的最佳实验条件，实验结果表明：含Cr(VI)废水经液膜处理后，Cr(VI)的去除率可达98％。     

Carrier-Mediated Transport of Molybdenum(VI) through Supported Liquid Membranes

Abstract

The liquid membrane transport of Mo(VI) from an acidic solution into an alkaline stripping solution was carried out by using a mobile carrier, 5,8-diethyl-7-hydroxy-dodecan-6-one oxime (LIX 63). Further transport of MoO₄ ^2? from the alkaline solution was performed by using another carrier, trioctylmethylammonium chloride (TOMAC). Molybdenum(VI) was effectively transported through double membranes composed of LIX 63/dilute NaOH solution/TOMAC from a feed solution (10^?3 M HNO₃) into a product solution (1 M NaOH). Molybdenum(VI) was concentrated with high recovery into a small volume of product solution. The separation of Mo(VI) from several ions was performed by means of the double membranes.     

L35-硫酸铵双水相体系萃取水溶液中Cr(VI)

以L35-(NH4)2SO4-H2O双水相体系萃取模拟废水中Cr(VI),考察了初始Cr(VI)浓度、水相pH值、胶束电荷调节剂1812用量、萃取时间、相分离时间、L35浓度、(NH4)2SO4浓度及萃取温度对Cr(VI)萃取率的影响. 结果表明,溶液pH值对Cr(VI)萃取率和分配系数影响最大;加入1812后,Cr(VI)萃取率和分配系数明显提高;随温度升高,两者均逐渐降低;随L35和(NH4)2SO4浓度增加,Cr(VI)萃取率逐渐提高并趋于恒定;萃取和相分离时间均较短;在最佳萃取条件下,Cr(VI)单级萃取率达92%(w),分配系数达15以上. 四级错流萃取的理论计算和实验结果基本一致,Cr(VI)浓度由2 g/L降到0.5 mg/L以下,达到国家排放标准. Cr(VI)依靠其相对疏水性以增溶方式及静电引力方式进入L35胶束内部而被萃取. 用NaOH水溶液对萃取相单级反萃取,Cr(VI)反萃率达99.5%(w)以上,浓缩倍数>4.