膜法海水淡化中试研究

采用超滤及反渗透膜法技术处理某钢铁厂热法海水淡化产生的浓水,浓水温度约为42℃,预处理采用冷却塔将原浓水温度分别降至32和28℃,分别采用一级和二级反渗透进行处理,考察了温度、反渗透级数对产水中氯离子浓度的影响,一级和二级反渗透系统的回收率以及预处理中砂滤及超滤的除浊效果。结果表明,随着水温的升高,系统对氯离子的去除率降低,当水温达到32℃时,采用一级反渗透无法保证产品水中氯离子浓度满足要求,系统采用一、二级反渗透产水混合方式即可满足出水水质要求;一级和二级反渗透的回收率分别为40%和90%;砂滤产水浊度受系统进水浊度影响严重,超滤产水浊度一直很稳定;系统脱盐率稳定达到99.7%以上。     

硼对反渗透海水淡化发展的影响预期

水资源量与经济社会发展需求相比严重不足,使得海水淡化迅速发展起来,规模呈大型化发展趋势,用途也逐渐从工业向市政供水扩展.很多人对海水淡化水作为饮用水的安全性存在疑虑,其中硼是人们一直比较关注的问题.概括了硼在海水中的存在形式、不同海水淡化方法产水的硼含量、脱硼方法及影响因素分析,同时介绍了国外大型反渗透海水淡化工程的脱硼情况、硼对人体健康的影响和对农作物的影响,以及国内外饮用水水质标准对硼含量的规定和发展趋势.     

两级反渗透系统中给、浓、产水的pH值分析

分析了一、二级反渗透系统中给水、浓水及产水pH值之间的关系,确定了一、二级系统透盐率最低时的给水pH值均为7.75,调节二级给水的pH值对全系统透盐率影响较大;得到了浓水、产水pH值随给水pH值的变化规律及其沿流程的变化趋势;明确了最佳给水、浓水加权平均p H值的概念。     

反渗透海水淡化脱硼技术研究现状

硼在水中以硼酸的分子形式存在,其浓度过高对农作物和人体会产生不利的影响。由于硼的分子半径小,且不具有电性,因此反渗透海水淡化需要与其他方法相结合才能使硼含量达到饮用水的卫生要求。介绍了目前反渗透海水淡化中的脱硼方法。     

北小河污水处理厂反渗透系统的调试运行和保存

北小河污水处理厂采用反渗透系统处理市政污水,规模为1×104m3/d,以MBR工艺作为预处理。在北京奥运会期间,反渗透产水供给鸟巢等奥运场馆。结合一年多的运行实践,分析了膜通量、进水电导率、温度、SDI值、水量波动、产水pH值、产水率、阻垢剂投加等因素对反渗透系统的影响;对反渗透前保安过滤器的运行模式、滤芯更换故障进行了探讨;结合清洗实例,分析了系统的污堵和运行情况,对清洗效果进行了评价;对系统停运后的保存方法进行了探讨,提出了反渗透工艺的合理运行模式及改造思路,可为今后市政污水处理反渗透系统的稳定运行提供参考。     

絮凝—沉淀一体化设备对海水的预处理效果

采用絮凝-沉淀一体化设备对渤海海水进行反渗透海水淡化预处理的试验,考察了该设备的处理效果。当聚合氯化铁（PFC）的投量为5．0mg／L、聚丙烯酰胺（PAM）的投量为3.0mg／L时,在适宜的pH条件下（pH值约为11）,经该设备处理后,出水的浊度〈1.0NTU,SDI值〈4．0,CODMn〈3.0mg／L。出水水质可满足反渗透工艺对进水的水质要求。     

脱盐水站浓水反渗透系统的节水改造

对某炼化企业脱盐水站浓水反渗透系统的节水改造进行技术可行性分析,设计新的工艺改造方案,选用高性能反渗透膜和高效膜阻垢剂,调节浓水进水pH值,实时优化系统回收率,改造后的浓水反渗透系统运行平稳,并取得了一定的经济效益。     

基于天然矿化材料的淡化海水再矿化实验研究

根据海水淡化反渗透出水水质低硬度和腐蚀性特征,利用CO₂酸化淡化海水溶解天然矿化材料(麦饭石、电气石和扇贝壳),进行再矿化处理,提高淡化海水的水质稳定性。研究pH值、进水流量和三种矿化材料组合对矿化效果的影响。结果表明,随着pH和进水流量的降低,矿化效果明显提高。在pH值为4.3、进水流量为30 L/h的条件下,随着麦饭石和扇贝壳的增加,添加少量的电气石,可以提高矿化出水的硬度、碱度、偏硅酸和锶溶出量。矿化产水经NaOH调质后,出水水质达到基本稳定状态,满足市政管网的供水要求,为淡化海水再矿化工艺中矿化材料的选择及组合提供了新的思路。     

两级膜法海淡系统的能耗及回收率模拟研究

膜法海水淡化系统设计的关键是有效降低系统能耗并提高回收率。试验建立了两级膜法海水淡化系统的数学模型,通过对该模型的计算分析,研究了能量回收装置、二级反渗透浓水回流措施及一、二级反渗透工况运行参数对系统比能耗和回收率的影响。结果表明,采用能量回收装置回收一级反渗透高压浓盐水的高压能极大降低系统比能耗,采取二级反渗透浓水回流至一级反渗透进水增压泵前的措施可有效提高系统回收率;当设置能量回收装置并采取回流措施时,系统比能耗的低值范围主要分布在一级反渗透回收率的低值区和二级反渗透回收率的高值区,而系统回收率的高值范围主要分布在一、二级反渗透回收率的高值区。当开展膜法海淡系统设计时,可采用提出的数模分析方法,在综合评判系统比能耗和系统回收率的基础上,确定系统优化策略,以求膜法海淡生产经营效益的最大化。     

天津反渗透海水淡化示范工程(1000m~3/d)

介绍了天津反渗透海水淡化示范工程(1 000 m3/d)的项目概况、工艺设计、设备配置、运行状况及造水成本分析.结果表明,针对天津海域海水浊度高、污染重的特点,采用初步预处理/双膜法淡化工艺完全能达到设计产水量和产水水质指标,并实现系统的稳定运行.     

Removal of boron compounds in pressure-driven desalination of the Black Sea water

The article has investigated the process of removing boron from the water of the Black Sea during its pressure-driven desalination using an OPMN-P nanofiltration membrane (ZAO NTTs Vladipor) and an ESPA-1 reverse-osmosis membrane (Hydronautics). It has been shown that the boron removal degree in a two-stage treatment (nanofiltration and reverse osmosis) is much lower than in a single-stage one (reverse osmosis). For the first time it was shown that there is a substantial impact of salts of calcium and magnesium on the boron retention coefficient with reverse-osmosis membranes. We have studied the conditioning process in terms of the content of boron (using an Amberlite IRA-743 boron-containing sorbent and the method of reverse osmosis in the alkaline medium) permeate obtained in the two-stage desalination of the Black Sea water.     

A comparative life cycle assessment of hybrid osmotic dilution desalination and established seawater desalination and wastewater reclamation processes

The purpose of this study was to determine the comparative environmental impacts of coupled seawater desalination and water reclamation using a novel hybrid system that consist of an osmotically driven membrane process and established membrane desalination technologies. A comparative life cycle assessment methodology was used to differentiate between a novel hybrid process consisting of forward osmosis (FO) operated in osmotic dilution (ODN) mode and seawater reverse osmosis (SWRO), and two other processes: a stand alone conventional SWRO desalination system, and a combined SWRO and dual barrier impaired water purification system consisting of nanofiltration followed by reverse osmosis. Each process was evaluated using ten baseline impact categories. It was demonstrated that from a life cycle perspective two hurdles exist to further development of the ODN-SWRO process: module design of FO membranes and cleaning intensity of the FO membranes. System optimization analysis revealed that doubling FO membrane packing density, tripling FO membrane permeability, and optimizing system operation, all of which are technically feasible at the time of this publication, could reduce the environmental impact of the hybrid ODN-SWRO process compared to SWRO by more than 25%; yet, novel hybrid nanofiltration-RO treatment of seawater and wastewater can achieve almost similar levels of environmental impact.     

Reverse osmosis desalination: Water sources, technology, and today's challenges

Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.     

过冷水动态制冰冷冻法处理酸铜电镀废水研究

电镀中常用的酸铜工艺的水洗废水为强酸性,pH值超过了反渗透膜允许的范围,无法应用反渗透法进行浓缩回用于电镀槽。为此,采用全新的过冷水动态制冰技术,对酸铜工艺电镀水洗废水进行冷冻法处理。结果表明,一次冷冻结晶冰融水的溶质去除率超过90%,可满足一级水洗槽补充水洗水的要求;二次冷冻浓缩液达到电镀槽电镀液浓度的80%,可回用于电镀槽补充电镀液。     

双膜法在防伪纸生产废水深度处理与回用中的应用

针对防伪纸厂废水处理站的二沉池出水,采用中试规模的连续膜过滤(CMF)/反渗透(RO)集成工艺进行深度处理,以期能够满足回用的要求.结果表明,超滤膜有较强的抗污染能力,其过滤出水浊度<0.5 NTU,SS值基本为零,SDI值<3,完全能够满足RO的进水要求;RO产水COD平均为1.7 mg/L,电导率为10 μS/cm,满足防伪纸生产工艺回用水质的要求.采用双膜法深度处理防伪纸生产废水并回用具有工程可行性.     

Full-scale simulation of seawater reverse osmosis desalination processes for boron removal: Effect of membrane fouling

The objective of this study is to further develop previously reported mechanistic predictive model that simulates boron removal in full-scale seawater reverse osmosis (RO) desalination processes to take into account the effect of membrane fouling. Decrease of boron removal and reduction in water production rate by membrane fouling due to enhanced concentration polarization were simulated as a decrease in solute mass transfer coefficient in boundary layer on membrane surface. Various design and operating options under fouling condition were examined including single- versus double-pass configurations, different number of RO elements per vessel, use of RO membranes with enhanced boron rejection, and pH adjustment. These options were quantitatively compared by normalizing the performance of the system in terms of E_min, the minimum energy costs per product water. Simulation results suggested that most viable options to enhance boron rejection among those tested in this study include: i) minimizing fouling, ii) exchanging the existing SWRO elements to boron-specific ones, and iii) increasing pH in the second pass. The model developed in this study is expected to help design and optimization of the RO processes to achieve the target boron removal at target water recovery under realistic conditions where membrane fouling occurs during operation.     

改良A~2/O工艺在长春北郊污水厂的应用

改良A2/O污水厂工艺运行稳定,具有较强的抗冲击性能,出水水质优于设计标准。平均进水COD为433mg/L时,平均出水COD为58.8mg/L,平均COD去除率达到86.3%,平均BOD5去除率达到91.8%,平均NH3-N去除率达到88.5%,平均TP去除率达到81.1%,均达到国家GB18918-2002污水排放一级B标准。