印染废水电渗析脱盐中试及影响因素

以某印染厂高密度澄清池出水为处理对象,通过中试试验确定了电渗析法的极限电流密度,研究了电压、进水流量对电渗析处理工艺出水水质的影响。结果表明中试条件下电渗析器的极限电流为25 A、极限电流密度为11.57 m A/cm2、最佳电压为80 V、单位容积电渗析器进水流量为5.2 L/h。在最佳工艺运行条件下电渗析淡水电导率低至1 500μs/cm,脱盐率、脱硬率和脱氯率分别达到78.07%、85.88%和88.50%。脱盐速率随着电压增大逐渐增大,当电压为85 V时脱盐速率出现最大值(56.35 mg/L·s);脱盐速率随着流量的增大逐渐减小,当流量为1 100 L/h时脱盐速率出现最小值(54.40 mg/L·s)。电渗析脱盐成本低,具有广阔的应用前景。     

1,3-丙二醇发酵液离子交换耦联电渗析脱盐的中试研究

对1,3-丙二醇发酵液离子交换耦联电渗析脱盐工艺进行了初步研究,在发酵液小试脱盐研究的基础上,主要研究了电渗析脱盐实验、离子交换树脂的选型和离子交换耦联电渗析工艺。结果表明,单独采用电渗析脱盐1,3-丙二醇损失率为11.41%;通过比较多种阴阳离子交换树脂的pH、电导率以及处理能力,确定耦联中试实验采用树脂LSI296和LSI010;采用离子交换耦联电渗析两步脱盐,效率提高到96.2%,损失率降低到5.88%。     

电渗析用于高含盐葡萄糖溶液的脱盐处理

采用电渗析技术对葡萄糖盐溶液进行脱盐处理,通过单因素实验探究了电流、葡萄糖浓度以及淡室初始盐浓度对电渗析脱盐效果的影响,确定了脱盐最佳操作工艺条件.实验结果表明,在电流为5A,葡萄糖浓度为0.05mol/L,淡室初始盐浓度为1.0 mol/L,电渗析处理90 min时脱盐效果最佳.在该操作条件下脱盐率为87.3％,葡萄...     

电渗析深度处理炼化废水回用试验研究

为降低炼化企业新鲜水消耗量及污水排放量,开展了电渗析脱盐深度处理炼化废水的工程化应用试验研究。通过20 t/h电渗析脱盐中试装置的3个月连续运行,探讨了电渗析脱盐深度处理炼化废水回用于循环水补水的可行性,并优化电渗析脱盐装置运行参数,考察装置连续稳定运行性能,为该技术的工程化推广应用提供参考。     

1,3-丙二醇发酵液电渗析脱盐工艺的优化

研究了1,3-丙二醇发酵液电渗析脱盐过程中某些工艺参数,例如不同交联度离子交换膜的选择、不同碱离子发酵液以及原料液预处理方式等工艺对脱盐过程的影响。同时在前期实验的基础上,研究了淡浓室流速比、淡室流速和浓室初始浓度三因素对电渗析脱盐操作过程的影响,并利用正交试验对脱盐过程的工艺优化作了进一步的探讨。     

α-癸基甜菜碱两性表面活性剂的电渗析脱盐

采用电渗析法对油脂基两性表面活性剂α–癸基甜菜碱进行脱盐纯化,考察了操作电压、淡室流量、溶液pH值等操作条件对电渗析脱盐的影响。实验表明,电渗析可有效脱除两性表面活性剂中的无机盐,在α–癸基甜菜碱两性表面活性剂的等电点pH值7.50,操作电压10 V,淡室流量20 L/h的条件下,α–癸基甜菜碱粗产品脱盐率达到92%,回收率92.3%。     

电渗析技术回收树脂脱附液中盐分中试研究

自制电渗析中试装置,用于某饮用水领域树脂脱附液盐分回收,在原有研究的基础上,对电渗析系统的运行条件和参数进行进一步优化。结果表明:电渗析中试浓缩室和淡化室的最佳运行流量为2.5 m~3/h;浓缩室和淡化室体积比取3∶1～4∶1为宜;饮用水脱附液的主要有机成分是腐殖质类荧光组分,电渗析运行前后料液的CODMn、三维荧光强度、UV-vis强度表现出相似的变化规律,即二级淡化液一级淡化液脱附液原液一级浓缩液二级浓缩液。     

无机高盐废水电渗析规律的研究

考察了自制一级一段式电渗析装置在焦化厂的高盐、高硬度废水中的脱盐效果和规律。为了防止结垢对膜组件的影响,首先对高盐、高硬度废水进行了软化处理,随后确定了该软化废水的分解电压,最后详细考察了运行时间、电压、中间室废水流量及阴、阳极室废水流量对电渗析脱盐效率的影响规律。结果表明,电渗析脱盐效率随运行时间的延长而逐步下降,随着电压的升高而增大,随中间室流量的减小而增加,随阴、阳极室流量的增大而升高。当操作电压为2.8 V,中间室流量为78 mL·h^-1,阴、阳极室流量为42 mL·h^-1,连续运行30和60 min时的平均脱盐效率分别为6.7%和6.4%。     

多级逆流电渗析技术用于硫酸铵水溶液脱盐

在恒流操作条件下,分别采用单级和多级电渗析对0.52mol/L硫酸铵水溶液进行脱盐实验.结果表明,采用多级逆流电渗析操作能明显缓解单级电渗析后期的浓差扩散和水渗漏现象.与单级电渗析相比,两级和三级电渗析淡室中盐脱除量分别提高了7.9%和22.5%,浓室中盐浓度提高了1.6%和6.5%,膜通量提高了7.0%和18.5%,能耗分别降低12.0%和32.0%.     

焦化生化出水电渗析脱盐研究

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。     

电渗析深度处理二级出水实现零排放和资源回收

采用电渗析法对二级出水进行深度处理实现"零排放",同时实现氮磷等资源的回收,考察了流速、电压和浓缩室电导率对脱盐率和氮磷回收率的影响。实验采用三膜对结构,结果表明,淡化室脱盐效果明显,电导率均可降到1μS/cm,氯离子、硝酸根和磷酸根去除率均在98%以上。改变反应器流速,发现流速较大时离子迁移更快,氮磷去除速率和回收率更高。减小外加电压,实验运行时间较长,迁移离子较慢,磷回收率下降。改变浓缩室电导率,电流效率和能量消耗等均未发生明显变化。     

倒极电去离子苦咸水淡化技术的试验研究

在常规电去离子(EDI)的浓缩室中采取与淡水室相同的树脂填充策略构成频繁倒极电去离子(EDIR)过程,以模拟苦咸水为处理对象,重点考察了阴阳树脂比例、树脂粒径、隔板厚度、树脂填充方式对EDI苦咸水淡化过程的影响。结果表明,在阴阳树脂体积比4:6、树脂粒径0.45～0.71 mm、采用隔板厚度3 mm以及树脂均匀混合填充时,可获得最低的产水能耗。对于3 000 mg/L的进水含盐量,EDIR的脱盐率可达90%以上,耗电量1.95 kWh/m3,过程运行稳定。EDIR有望成为具备较强竞争力的苦咸水淡化新技术。     

电渗析法处理污染三甘醇工艺优化研究

以长庆靖边气田被污染的三甘醇溶液为实验对象,采用四室电渗析反应器对其进行净化处理,研究了操作电压、运行时间、淡室进液流量、进液总溶解性固体(TDS)浓度等因素对处理后溶液品质的影响。在单因素实验的基础上,采用响应面分析法对电渗析工艺进行了优化。优化的工艺条件为:操作电压48.92 V,运行时间128.09 min,淡室进液流量12.00 L/h,当被污染的三甘醇溶液TDS质量浓度为1 968 mg/L时,在此工艺条件下处理后TDS浓度可降至(38.3±1.2)mg/L。实验中对电渗析过程的极限电流进行了测定,在淡室进液流量为12.00 L/h时,测得极限电流为0.189 A,对应的极限电压为66 V,说明装置在优化条件下运行不会出现浓差极化等不正常现象。     

Desalination in Mexico

For the last 20 years Mexico has been gradually installing desalination plants for a diversity of purposes. Within the Mexican government desalination acitivities have been promoted by two agencies. The first has been responsible for desalination in service of better quality water for power generation while in the alternate the emphasis has been in brackish and saline water conversion for community potable and consumer related water supplies. The private sector has in most instances also relied on the government agencies for satisfying of industrial needs but not to the exclusion of private industry desalination plant construction.The paper presents the facts on accomplishments here. It comments on the effectiveness of the approach utilized by the government agencies active in the field and on the possible and potential impact of the use of desalination by the private sector.     

Application of the analytical hierarchy process in the selection of desalination plants

Seawater desalination plants have been utilized to supply fresh water to the Gulf Cooperation Council countries since the early 1950s. In spite of the fact that there are several types of desalination technology that can be used more efficiently and economically, one type of desalination technology, namely multi-stage flash, has been used extensively in the region. This work is an attempt to identify the most suitable technology for the specific use by soliciting expert opinions. Based on several relevant factors, the analytical hierarchy process (AHP) was utilized to select the most appropriate technology for seawater desalination. The selection process in this study was limited to seawater feed and seven factors and four commercially available desalination technologies, i.e., multi-stage flash, multi-effect desalination, vapor compression and reverse osmosis.     

二硫化钼作为海水淡化材料的研究进展

海水淡化是从丰富的海水资源中提取清洁淡水的技术,是解决淡水资源短缺的重要途径。传统的海水淡化技术在实际应用中已经暴露出高成本、高能耗和低效率等缺点,因此开发海水淡化新兴技术及材料成为研究重点。二硫化钼（MoS₂）是典型层状过渡金属硫化物,因其化学稳定、吸光能力优异等优点,在海水淡化领域具有极大的应用前景。作为一种高效环保的海水淡化材料,MoS₂及其复合材料在改善传统脱盐工艺和发展新兴脱盐技术中已得到广泛研究。本文主要论述和分析MoS₂基材料在电容去离子、膜脱盐及太阳能脱盐等海水淡化应用中的研究进展以及在工业化应用中面临的挑战,并展望其今后在脱盐领域的发展方向。     

Semiempirical kinetic modelling of water desalination by electrodialysis processes

Water desalination was performed by electrodialysis (ED) in batch recirculation mode by means of cationic and anionic membranes containing sulfonate and ammonium groups, respectively. Variations in sodium chloride (NaCl) concentration in dilute compartment versus time during ED experiments were recorded at different voltages, flow rates, and feed concentrations. ED experiments were modelled by means of a semiempirical kinetic model. A good agreement is found between experimental data and the model.     

Current challenges in hydrate-based desalination: Kinetic and thermodynamic perspective

Water scarcity is becoming a severe problem worldwide due to inadequate freshwater resources and swift population growth. Seawater desalination is one of the vital approaches to meet the demand for freshwater. However, energy and associated costs with conventional seawater desalination techniques are incentivizing non-conventional water desalination processes. Water desalination using gas hydrates formation is one of the emerging non-conventional processes. In this perspective article, recent advances in hydrate-based seawater desalination (HBSD) have been critically analyzed to outline a future path towards a clean and efficient hydrate-based desalination process. It provides a detailed comparison of various processes developed over decades, and measured desalination efficiencies with their process details. Moreover, the current challenges, limitations, and future perspectives of hydrate-based desalination are also discussed. The study also recapitulates the thermodynamics and kinetics aspects of the hydrate-based desalination process. In addition, various factors controlling the desalination efficiencies, such as control of the separation of hydrate crystals, salt deposition on hydrate particles, and hydrate morphology, were thoroughly investigated with their proposed process designs. The kinetics of hydrate formation is also assessed, with the possibility of a zero-induction regime and its consequent impact on hydrate morphology. The current capabilities of the thermodynamics models (Gibbs energy minimization + electrolyte equation of state) were discussed using various commercially available software. Additionally, the role of hydrate promotors is also discussed, which can reduce the higher cost associated with the hydrate-based desalination process.