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EDI产水水质影响因素的试验及分析 总被引:1,自引:0,他引:1
研究了淡、浓水流量对膜堆电流、电压的影响,并重点研究了当膜堆电流一定时,淡、浓水流量对EDI产水水质的影响。结果表明:淡水流量的变化对膜堆电流的影响很小;增加浓水流量会减小膜堆电流。当膜堆电流一定时,淡、浓水流量对产水水质的影响主要取决于进出口的淡、浓水压差。当进出口的淡、浓水压差足够时.EDI的产水水质能够得到保证:反之,产水水质则会发生恶化,其中以出口处的淡、浓水压差对产水水质的影响更为突出。试验还发现,当膜堆电流一定时,淡水流量过低会导致产水水质下降;浓水流量的增加则有利于产水水质的提高. 相似文献
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研究了淡、浓水流量对膜堆电流、电压的影响,并重点研究了当膜堆电流一定时,淡、浓水流量对EDI产水水质的影响。结果表明:淡水流量的变化对膜堆电流的影响很小;增加浓水流量会减小膜堆电流。当膜堆电流一定时,淡、浓水流量对产水水质的影响主要取决于进出口的淡、浓水压差。当进出口的淡、浓水压差足够时(大于0.02MPa),EDI的产水水质能够得到保证;反之,产水水质则会发生恶化, 相似文献
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减压膜蒸馏法浓缩反渗透浓水试验研究 总被引:9,自引:2,他引:7
利用新型聚偏氟乙烯(PVDF)中空纤维疏水膜,采用减压膜蒸馏(VMD)法对石化企业废水的反渗透(RD)浓水进行脱盐、浓缩处理.研究了对浓水及预处理除硬后浓水的VMD浓缩过程中膜的通量、产水和浓缩液水质的变化规律;采用扫描电镜(SEM)及能谱议(EDS)分析了膜表面形貌及元素组成,研究了VMD过程通量下降的原因.结果表明,微溶无机盐的沉积是造成VMD过程通量降低的主要原因.RO浓水经过预处理后,在真空度0.095MPa,原水温度70℃,流速0.66m·s-1,的条件下,VMD过程通量达25.83 kg·m-2·h-1将其浓缩至20倍时通量仍保持在11.7 kg·m-2·h-1,产水电导保持在4 uS·cm-1以下. 相似文献
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采用电渗析技术对焦化生化出水如曝气生物滤池出水及反渗透浓水进行脱盐,考察不同废水中的离子迁移、废水脱盐及离子交换膜污染情况。结果表明:2种焦化废水采用电渗析处理具有较好的脱盐效果,其中不同离子的迁移脱除与其浓度、离子半径等密切相关。膜电阻测试表明,不同焦化废水电渗析体系中不同离子交换膜的污染存在差别。扫描电镜和红外分析表明,曝气生物滤池出水主要由有机物造成阴离子交换膜污染,而反渗透浓水主要在电渗析浓室侧的膜表面形成颗粒状的无机污染,且阳膜浓室侧比阴膜浓室侧更显著。 相似文献
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系统分析了膜堆构型、工艺流程和工艺参数对ED脱盐过程的能耗和脱盐效果影响,采用脱盐率、能耗和电阻来表征ED膜堆性能。结果表明,在膜堆结构方面,脱盐率为30%时,填充树脂的膜堆相比未填充的膜堆节约能耗约33.3%;采用均相膜的膜堆比采用非均相膜的节约能耗约27.8%。工艺流程方面,脱盐率为30%时,浓淡水逆流的膜堆吨水能耗比顺流的膜堆节约能耗约16.8%;极水并联的膜堆能耗比极水串联的膜堆能耗节约约11.1%,一极两段的膜堆能耗比一极一段的膜堆能耗约节约26.3%;在工艺参数方面,在苦咸水含量范围内,相同的脱盐率的条件下,提高浓度进水、降低浓淡室流量有利于降低ED过程的能耗。 相似文献
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A steady-state model was established to simulate EDI process for producing ultrapure water (MixEDI), the dilute compartment of which is filled with mixed cation and anion-exchange resins. By calculating the mathematical model which includes water dissociation mechanism, ionic status of ion-exchange resin, concentration polarization status and the concentration distribution of water dissociation products are obtained. The influence of water dissociation on the current efficiency, removal rate and pH value of EDI effluent is investigated. The existence of water dissociation catalyst at anion-exchange membrane (AM) makes the water dissociation current of the AM much larger than that of CM. The result is that the amount of electro-regenerated cation-exchange resins is much larger than that of anion resins. This is the reason why the removal rate of salt cation much larger than that of salt anion in EDI for producing ultrapure water. Thus, at the target percentage removal, water dissociation at AM surface is excessive and the one at CM surface is insufficient. We assume that there is also some water dissociation catalyst at CM surface. It is found that the improved water dissociation at CM could increase the percentage removal of salt anions and the current efficiency. 相似文献
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为了实现化工行业高纯水全自动生产,本文利用电除盐(electrodeionization,EDI)技术替代传统的混床技术,并研究了人工神经网络对EDI产水过程模拟仿真的可行性,采用误差反向传播网络(BP网络)建立了进水流量、电导率、pH值以及工作电压与EDI透过水电阻率之间关系的动态模型,并对不同的训练样本归一化方法和训练方法进行比较。结果表明,在网络隐含层层数为1、节点数为13时,采用归一化方法三能够较好的预测EDI透过水电阻率,且该模型可用于EDI除盐过程的动态描述,为实现化工行业高纯水全自动生产奠定了基础。 相似文献
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在玉门炼化总厂老脱盐装置上进行了青西原油电脱盐超声破乳工业试验,介绍了工艺流程、超声波破乳原理及试验方法。实验结果表明,使用超声波替代破乳技术后,原油的含盐量由脱后的平均148.09mg.L-1降低到37.01mg.L-1,达到脱后小于50.0mg.L1的指标要求,同时电脱盐操作电流由平均150A下降到35A左右,且电脱盐操作运行平稳,总排水的水质得到明显改善。 相似文献
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The electrodeionization process (EDI) is usually operated at overlimiting current density, and is thus characterized by water dissociation and concentration polarization. We attempt to study the useful and harmful effects of water dissociation on the EDI process. A numerical steady state model was established to simulate the process of EDI, accounting for the effects of water dissociation. The differences in concentration polarization of membranes were investigated to study the effects of water dissociation on cation and anion membranes. Protons produced by water dissociation caused the resin to transform into the H-form. The H-form resin, which has high conductivity and high transport number, depletes protons in the interstitial solution. This explains the experimentally detected phenomenon that at high current densities, the pH value of the effluency of the dilute compartment (DC) stops decreasing when current increases. We suggest that the useful role of water dissociation in EDI is due to the H-form resin bringing more salt cations of the interstitial solution into the resin phase, thus producing a high conductivity channel for the electro-migration of the salt cations. This mechanism avoids the decrease in salt ion conductivity brought about by concentration polarization. The disadvantageous effect of concentration polarization on the transportation of salt ions in interstitial solution is thus lessened. An intermediate point between the useful and harmful effects of water dissociation was determined by the dependence of current efficiency and removal rate for both cations and anions as a function of current density. 相似文献
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采用烧杯混凝实验,分别以实验室配水和松花江水为本底,研究了水合二氧化锰强化三氯化铁共沉降去除水中微量镉的效能。详细探讨了影响水合二氧化锰强化三氯化铁共沉降去除水中微量镉的主要因素。结果表明:两种水质条件下,水合二氧化锰均可强化FeCl3混凝去除水中的微量镉,镉的去除率明显高于单纯FeCl3混凝。水体pH值、浊度、腐殖酸等水质参数对于水合二氧化锰强化三氯化铁共沉降去除水中微量镉的效能有不同程度的影响。其中水体pH值对水合二氧化锰强化三氯化铁共沉降去除水中微量镉的影响十分显著,Cd(Ⅱ)的去除效果随着水体pH增加显著升高。 相似文献