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采用扩散渗析法回收含铜退镀液中的HNO3,考察流量、流量比、温度等因素对硝酸的回收率、回收液中硝酸浓度以及铜和镍离子截留率的影响.将单级扩散渗析仪改装成新的三级扩散渗析仪,考察了三级逆流扩散渗析对实验结果的影响.单级扩散渗析的结果表明,最佳条件:水/料的流比为1∶1、流量90 mL/h、温度19℃,其硝酸回收率为86.95%、回收浓度6.04 mol/L、Cu2+和Ni2+的截留率分别为90.19%、92.71%.相对于单级扩散渗析,自行改装的三级扩散渗析过程能达到更高回收酸浓度和单位时间内处理更多的料液.在含铜退镀液体系下,利用国产扩散膜实现了扩散渗析对于H+和金属离子具有良好的分离,同时达到了回收硝酸浓度高于原退镀液的效果. 相似文献
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《膜科学与技术》2019,(5)
甲基二乙醇胺(MDEA)溶液在吸收天然气中的CO_2时发生可逆化学反应,因此对MDEA富液的再生可进一步完善天然气生产工业.实验采用聚丙烯(PP)膜组件作为富液再生器,利用减压膜蒸馏法再生含CO_2的MDEA富液.研究富液温度、真空度、流量和富液中CO_2浓度对分离因子和脱碳率的影响,探究各参数影响能力的大小并寻找出最佳操作参数.研究表明,脱碳率随温度、真空度、流量和CO_2浓度增大而增大;分离因子随温度、真空度和CO_2浓度增大而增大,随流量增大而减小.最佳操作条件为温度50℃,真空度65 kPa.各参数对减压膜蒸馏影响顺序为温度真空度流量CO_2浓度. 相似文献
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电渗析法回收含Cu,Fe,Ni硫酸溶液中的硫酸 总被引:4,自引:0,他引:4
本文研究了用电渗析法从含铜、铁、镍离子的酸性溶液中回收硫酸的行为。测定了电流密度、给液的初始酸浓度、金属离子类别和浓度对硫酸回收效率的影响,实验结果表明:给液中初始硫酸浓度为10 ̄200g/l,金属离子浓度4 ̄50g/l时,硫酸可以通过电渗析法有效地进行回收,有少量金属离子随同硫酸一起进入产物液,对产物液的污染程度为:铜>>铁>镍,这一现象可由实验所测得的膜电阻:铜<铁<镍得到解释。电渗析过程中硫 相似文献
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为了解决精氨酸生产过程中的无机酸回收和循环再利用问题,采用阴膜扩散渗析法,针对模拟的精氨酸和盐酸混合液,在静态扩散条件下测定了盐酸的渗析系数,并考察动态扩散渗析操作参数如流速、流速比对酸回收率的影响.结果表明,采用DF-120阴离子交换膜,在静态扩散渗析中,盐酸能够顺利地透过膜,精氨酸几乎不能透过;动态扩散实验中流速、流速比对酸的回收率和回收酸的浓度有重要影响:随着流速的增加,盐酸的回收率逐渐降低,精氨酸的截留率基本上没有改变,均达到98.5%以上;流速为2 mL/min时,盐酸回收率最高,可达82%;水/料液流速比增大时,盐酸的回收率增大,但是过高的水/料液流速比又会使回收酸的浓度降低.经济核算表明,对于一个年产30 t精氨酸的装置,相对于中和法,膜扩散渗析法一年能节省的化学原料总费用约98万元,投资回收期为8个月. 相似文献
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采用溶液相转移法,通过特殊结构的纺丝喷头,制备了品字形PVDF中空纤维膜,讨论了PVDF固含量和芯液组成对品字形膜形态结构和性能的影响。结果表明,随PVDF固含量的增大,品字形膜支撑层空穴变小,膜丝外形融合程度减小,海绵体结构更致密,超滤水通量、透气系数和膜蒸馏通量相应减小,膜丝断裂强力增大;随芯液中溶剂DMAc含量的增加,品字形膜支撑层空穴变小,融合部分海绵体变致密,超滤水通量、透气系数减小,膜蒸馏通量略微提高,膜丝断裂强力增大;优化后的品字形膜的水通量较单芯膜有所降低,但断裂强力显著提高,接近单芯膜的3倍。 相似文献
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正渗透是新的非热能驱动膜过程。采用界面聚合的方法制备了中空纤维复合膜。以Na2SO4、MgSO4、NaCl和Mg-Cl2水溶液作为驱动液进行了正渗透实验。实验表明,正渗透通量随着驱动液浓度的增加而增加,其中Na2SO4、MgCl2水溶液的渗透通量大于MgSO4、NaCl水溶液的。驱动液中无机盐向原水中扩散的渗透速率随无机盐浓度的增加而增加,且MgCl2>NaCl>Na2SO4>MgSO4。原水流速对正渗透通量的影响极小,而驱动液流速对正渗透通量的影响较大。 相似文献
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Mahmood Aliofkhazraei Eskandar Keshavarz Alamdari Mohammad Zamanzade Mobin Salasi Saeed Behrouzghaemi Jafar Heydari D. F. Haghshenas Vahid Zolala 《Journal of Materials Science》2007,42(23):9622-9631
Electrical conductivities and densities of acidic zinc, cadmium and manganese sulphate solutions were measured. Empirical
equations have been derived to represent the measured values with high accuracy. Electrical conductivity of solutions has
been shown to be expressed as a logarithmic function of temperature, a second order polynomial function of sulphuric acid
concentration and a linear function of metal ion concentration. It can be deduced that the density of solution can be described
as a linear function of metal ion concentration, temperature and sulphuric acid concentration. These equations could be used
to improve the electrowinning or electrorefining process conditions. 相似文献
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This work investigated the performance of ammonium sulphate as a draw solution in a fertilizer drawn forward osmosis (FDFO) desalination process using thin-film composite (TFC) membrane. Performance has been assessed by the water flux, reverse permeation and the forward rejection of the feed solutes. A logarithmic relation has been determined between flux and ammonium sulphate concentration. As water flux increased, the specific reverse solute flux (SRSF) of NH4 + and SO4 2? ions dropped, which is a favourable condition. Reverse permeation values obtained at flux less than 10 L/m2/h are significantly higher than that for flux more than 10 L/m2/h. Thus, it is recommended to operate the process at a flux higher than 10 L/m2/h to avoid loss of draw solute by reverse permeation. SRSF was almost constant irrespective of ammonium sulphate concentration. TFC membrane used in this study exhibited high rejection of feed solution ions for almost all draw solution concentrations except when operated at low ammonium sulphate concentration and high feed solution concentration. In conclusion, ammonium sulphate is an efficient draw solution for FDFO process when run at water flux more than 10 L/m2/h exhibiting high osmotic pressure, low reverse solute permeation and high rejection of feed solute. 相似文献
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膜蒸馏淡化处理油田高含盐废水的实验研究 总被引:12,自引:2,他引:12
采用减压膜蒸馏技术处理油田高含盐废水,研究了真空度、废水温度、流量以及废水含盐量对膜通量与截留率的影响。实验结果表明:随着膜下游真空度增加,膜通量先缓慢增大,当真空度超过某一临界值后,膜通量急剧增加;废水温度增加,膜通量增大,且真空度越高,膜通量随温度变化的曲线越陡;提高废水流量可增大膜通量;随着废水含盐量增加,膜通量减小,当废水含盐量大于220g/L时,馏出液电导率明显增加,但各次实验的截留率仍然接近100%,表明实验用聚丙烯中空纤维膜具有很好的疏水性。 相似文献
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Mahmoud A. Zarraa 《Materialwissenschaft und Werkstofftechnik》1996,27(11):540-545
The effect of surfactants on the rate of diffusion-controlled cementation of copper from dilute copper sulphate solutions on a stationary zinc disc in a stirred vessel was studied. Variables investigated were rotational speed of the impeller, concentration and type of surfactants and concentration of copper sulphate solution. These variables were studied for their effect on the mass transfer coefficient of copper cementation. The mass transfer coefficient was found to increase with increasing rotational speed of the impeller and concentration of copper sulphate solution. It was found that surfactants decrease the rate of mass transfer during cementation by an amount ranging from 9.5 to 25° depending on the rotational speed of the impeller and type of surfactant added. Increasing surfactant concentration was found to decrease the mass transfer coefficient. The ability of different surfactants to decrease the mass transfer coefficient increases in the order: CTMAB < SABS < NPPGE. Mass transfer data were correlated, in absence and in presence of surfactants, by the following equations respectively: Where Sh is Sherwood number, Re is Reynolds number, and Sc is Schmidt number. 相似文献
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稀土对42CrMo钢等离子体氮碳共渗表层组织的影响 总被引:1,自引:0,他引:1
对42CrMo钢在不同温度和时间下进行有、无稀土添加的脉冲等离子体氮碳共渗的工艺进行研究。通过金相检验和XRD分析,归纳出稀土对等离子体氮碳共渗的影响。结果表明:稀土的添加改善了渗层的显微组织,并降低了渗氮初期的化合物层厚度;使渗层的e相含量降低,γ'相含量增加;并且使表面氮含量提高。 相似文献
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PVDF疏水中空纤维膜的膜蒸馏含盐废水处理性能研究 总被引:5,自引:0,他引:5
利用新型高通量聚偏氟乙烯(PVDF)中空纤维疏水膜,对石化企业废水经反渗透(RO)处理的浓排水进行减压膜蒸馏(VMD)处理实验.研究了RO浓排水流速、温度和冷侧真空度对VMD过程中PVDF膜性能的影响,考察了PVDF膜在VMD法RO浓水浓缩过程中的性能变化.结果表明,原液流速对膜性能无明显影响;原液温度或冷侧真空度提高都会使膜的产水通量明显上升,而产水电导保持稳定.在冷侧真空度为-0.095MPa、原液温度70℃、流速0.66m/s的条件下,经15.2h实验,将RO浓排水浓缩20倍,膜的产水通量从25.8L/(m2*h)降低至11.8L/(m2*h),产水电导低于4霺/cm,脱盐率高于99.99%,产水CODCr值约30mg/L.经过5次浓缩实验后,PVDF膜的通量和产水电导均保持稳定. 相似文献
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以聚全氟乙丙烯(FEP)为成膜聚合物, 采用熔融纺丝-拉伸法制备FEP中空纤维膜, 研究了后拉伸倍数对FEP中空纤维膜结构与性能的影响。结果表明, 初生FEP中空纤维膜结构较为致密, 拉伸后出现微孔结构。随着拉伸倍数的提高膜的孔隙率和氮气通量明显增大, 而液体渗透压(LEP)有所降低。将所得FEP中空纤维膜用于减压膜蒸馏(VMD)研究, 并将其与常规熔融纺丝-拉伸法聚丙烯(PP)中空纤维膜比较。结果表明, 所得FEP中空纤维膜的疏水性能、液体渗透压力和力学强度均优于PP中空纤维膜。较强的疏水性能使其稳定运行而不被液体渗透, 脱盐率稳定在99%以上。同时, FEP中空纤维膜具有较大的内径(0.74 mm), 在保证较高脱盐率前提下可采用内压式减压膜蒸馏, 且真空膜蒸馏通量随着进料温度的升高显著增高。 相似文献