共查询到19条相似文献,搜索用时 156 毫秒
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工业循环冷却水旁流软化-净化处理技术进展 总被引:2,自引:0,他引:2
概括叙述了工业循环冷却水系统旁流处理在节约用水量、降低处理成本、改善水处理效果和减轻排污水环境污染等方面的作用,深入分析了石灰-纯碱软化、弱酸树脂软化和膜分离技术等软化或净化处理单元的工艺原理、影响因素和研究进展,重点介绍了HEROTM、电渗析"零排放"、Hydronautics"零排放"和三级旁流处理技术等组合工艺的基本流程、工艺特点和应用前景,探讨了工业循环冷却水旁流处理技术的研究方向和具体要求. 相似文献
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采用“化学软化+TUF”对焚烧厂垃圾渗滤液MBR产水进行预处理,探究了不同Ca(OH)2加药量的软化效果、管式超滤膜的运行稳定性及组合工艺的处理效果、膜污染控制方式和反渗透运行稳定性。结果表明:Ca(OH)2加药量占比为90%时,组合工艺对硬度、SiO2、COD的去除率分别为94.3%、66.7%、30.0%,出水浊度为0.22 NTU,说明组合工艺对硬度、COD、SiO2、浊度均有较好的去除效果。管式膜产水平均通量在390 L/(m2·h)左右,运行压力稳定在0.25 MPa,通量和压力运行稳定,反洗通量恢复性好。采用HCl(5%)+NaOH(3%)+NaClO(5%)的化学清洗方式可能较好地恢复膜通量。组合工艺除硬除浊处理后,后续反渗透运行稳定性明显改善。本研究可以为“化学软化+TUF”在焚烧厂渗滤液废水预处理阶段的应用提供参考。 相似文献
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纳滤膜脱盐性能及其在海水软化中应用的研究 总被引:6,自引:0,他引:6
选择了ESNA1型纳滤膜对NaCl、MgCl2、Na2SO4、MgSO4等4种无机单盐水溶液体系进行分离实验;考察操作压力和料液浓度等的变化对纳滤膜分离性能的影响及纳滤膜脱盐的稳定性,得到一些纳滤膜脱盐的规律;并对ESNA1膜在人工海水和海水软化脱盐中的应用作了初步探索.无机盐体系脱盐实验结果显示:随操作压力升高和料液浓度增大,ESNA1膜对4种盐溶液中的离子的截留率分别增大和减小,操作压力和料液浓度的变化对一价盐溶液的截留率影响较大,对二价盐溶液的截留率影响较小.人工海水和海水软化脱盐试验结果显示:ESNA1纳滤膜在实验过程中稳定性好,在较低的操作压力下膜通量也较高,且ESNA1纳滤膜对Ca2 、Mg2 、SO42-离子的截留率均>90%,初步判断此种纳滤膜可用于海水软化预处理. 相似文献
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以阜阳市某生活垃圾填埋场渗滤液为研究对象,针对渗滤液高硬度、低碱度的特点,考查软化+微滤膜中试工艺对填埋场总硬度的处理效能,分析微滤膜运行参数对膜通量和产水流量的影响.中试结果表明:软化+微滤膜工艺可有效去除水源中钙镁离子污染问题,控制软化装置的反应池pH在11.5,总硬度(以CaCO3计)的去除率在94%以上,出水总硬度(以CaCO3计)稳定<100 mg/L.软化微滤工艺对渗滤液中COD的平均去除率为16.2%.单支微滤膜正常运行,反洗频率30 min时,可将膜通量恢复至初始通量的90%以上.由中试可知,微滤膜具有良好的抗污染性能,在进膜污泥浓度为4.97 g/L及以上时,初始膜通量仍能保持较高值. 相似文献
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CO2再生离子交换法是一离子交换的新工艺。由于这种工艺采用价廉而对环境无污染的CO2作再生剂,所以这种工艺颇为人们所重视。本文讨论了这种工艺的原理,介绍了在水的软化和脱盐处理中采用这种工艺的初步结果,最后对这种工艺在工业水处理中推广应用的前景进行了探讨。 相似文献
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纳滤膜软化技术在海岛饮用水制备中的应用 总被引:23,自引:3,他引:20
本文以海岛高硬度苦咸水为水源 ,采用纳滤膜软化技术制备饮用水 ,系统连续正常运行 2 7个月 ,淡化水符合国家生活饮用水卫生标准。文中还以纳滤的分离特点及高硬度下实际运行的注意点作了进一步的探讨 相似文献
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当反渗透进水硬度过高时,容易污堵膜,需要采用预处理进行软化,文章研究了进水在经过双碱软化之后,硬度下降60%,但产水电导率和COD与没有经过软化时相比较没有大的变化,都能够达到很高的去除率.最重要的是膜的污堵状况得到了很大的改善,使得膜的清洗周期延长到没有软化前的三倍. 相似文献
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Nanofiltration (NF) membrane process has become increasingly attractive due to their unique characteristics to selectively remove specific compounds or ions. The most commonly NF membranes are negatively charged which is unsuitable for hardness removal. Therefore, the development of novel NF membranes with a positively charged skin has become a key issue for low pressure water softening. 相似文献
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操作条件对NF90膜软化水过程的影响 总被引:1,自引:0,他引:1
以模拟硬水为水样,针对压力、温度和pH值等操作因子对NF90型纳滤膜软化水过程的影响进行了试验研究。结果表明,在处理暂时硬度为300 mg.L-1(以CaCO3计)的硬水时,NF90膜有较高的通量和Ca2+截留率,适用于水质软化过程。在操作压力为0.5~2.0 MPa、温度为13℃~37℃、水样pH值为6.0~8.0的条件下,膜通量随操作压力、温度的升高而升高,但受pH值的影响不大。在试验条件范围内,Ca2+的截留率均>97%。 相似文献
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为解决工业冷却循环水系统中水垢沉积导致换热效率降低和管路腐蚀等问题,本文提出了一种电化学-微滤耦合反应体系,以Ti/SnO2-Sb2O5-RuO2-IrO2钛滤膜为阴极,利用电解过程营造的局域强碱性和本身的微滤功能,同步实现钙硬度的高效结晶与分离。在膜反洗阶段,倒极后钛滤膜为阳极,其原位电解产生的H+能够溶解附着在膜表面和孔道内的水垢,实现水垢的剥离。结果表明,膜孔径越小,钙硬度去除率越高,以孔径为2μm的钛滤膜作阴极时,钙硬度去除率可达79%。电流密度从1mA/cm2增加到5mA/cm2时,钙硬度去除率从28%增加至86%,但电流密度进一步增加至10mA/cm2后,钙硬度去除率下降至78%。碱度增加有利于钙硬度的去除,当[HCO3-]/[Ca2+]摩尔比从0.7∶1提升至1.4∶1时,钙硬度去除率从53%增加至83%。当流速从5mL/min增加到20mL/min时,钙硬度去除率从84%下降至46%,能耗由3.06kWh/kgCaCO3降为1.38kWh/kgCaCO3,远低于传统电化学除硬体系。膜表面滤饼形成和膜孔内堵塞是引起钛滤膜污染的主要机制,经极性反转后,膜通量可恢复至78%左右。XRD和SEM分析表明,钛滤膜表面富集的CaCO3主要为方解石晶型。电化学-微滤耦合除硬以及膜反洗过程主要由电子驱动,避免了大量膜清洗剂的使用,为循环水系统中硬度离子的去除提供了新思路。 相似文献
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Lebea N Nthunya Leonardo Gutierrez Sebastiaan Derese Edward N Nxumalo Arne R Verliefde Bhekie B Mamba Sabelo D Mhlanga 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2019,94(9):2757-2771
Membrane distillation (MD) is a thermally driven process that uses low-grade energy to operate and has been extensively explored as an alternative cost-effective and efficient water treatment process compared to conventional membrane processes. MD membranes are synthesized from hydrophobic polymers, e.g. polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) or polypropylene (PP), using various methods including phase inversion and electrospinning techniques. Recent literature on MD membranes clearly shows their important role in surface water/wastewater treatment and seawater desalination. Modification of MD membranes with nanoscale materials significantly improves their performance, preventing wetting and fouling. This review presents a critical assessment of the progress on the use of nanomaterials for the modification of MD membranes. The techniques commonly used to synthesize MD membranes, the modifications that have been adopted for the incorporation of nanomaterials onto membranes, and the unique properties these nanomaterials impart on the membranes are discussed. The use of modified membranes in different MD configurations and their application in groundwater, surface water, wastewater, brackish water and seawater treatment is reviewed. Finally, cost implications, commercial viability, environmental sustainability, and future prospects of MD are also discussed to elucidate promising approaches for a future and successful implementation of MD at an industrial scale. © 2019 Society of Chemical Industry 相似文献
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C Charcosset I Limayem H Fessi 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(3):209-218
Membrane emulsification has received increasing attention over the last 10 years, with potential applications in many fields. In the membrane emulsification process, a liquid phase is pressed through the membrane pores to form droplets at the permeate side of a membrane; the droplets are then carried away by a continuous phase flowing across the membrane surface. Under specific conditions, monodispersed emulsions can be produced using this technique. The purpose of the present paper is to provide a review on the membrane emulsification process including: principles of membrane emulsification, influence of process parameters and industrial applications. Small‐scale applications such as drug delivery systems, food emulsions, and the production of monodispersed microspheres are also included. Compared with conventional techniques for emulsification, membrane processes offer advantages such as control of average droplet diameter by average membrane pore size and lower energy input. Copyright © 2004 Society of Chemical Industry 相似文献