Impacts of Climate Change on Seawater Temperature and Total Dissolved Solids: Challenges and Sustainable Solutions for Reverse Osmosis Desalination in the Arabian Gulf Region

This article examines the influence of seawater temperature and total dissolved solids (TDS) on reverse osmosis (RO) desalination in the Arabian Gulf region, with a focus on the impact of climate change. The study highlights the changes in seawater temperature and TDS levels over the years and discusses their effects on the efficiency and productivity of RO desalination plants. It emphasizes the importance of monitoring TDS levels and controlling seawater temperature to optimize water production. The article also suggests various solutions, including intensive pre-treatment, development of high-performance membranes, exploration of alternative water sources, and regulation of discharges into the Gulf, to ensure sustainable water supply in the face of rising TDS levels and seawater temperature. Further research and comprehensive monitoring are recommended to understand the implications of these findings and develop effective strategies for the management of marine resources in the Arabian Gulf.

SWRO+MCR工艺处理电镀废水零排放工程研究

针对某电镀公司生产线排放废水的特点及相关处理要求,采用反渗透海水淡化装置(SWRO)与膜化学反应器(MCR)工艺,并结合高频电力系统,对含镍、含铬及综合电镀废水进行了处理,处理规模总计为60 m^(3)/d。结果表明:经SWRO+MCR工艺处理后的电镀废水,出水水质满足标准GB/T19923-2005标准中的相关要求,出水可全部回用于工业用水及杂用水,处理后干污泥及蒸发釜液则委外处置,实现了电镀废水的零排放。工程总费用约为643万元,废水处理成本约为97.27元/m^(3)。可见,工艺流程及工程案例能够为电镀废水的零排放处理工艺创新及同类项目提供一定的参考。

指向社会责任的“海水稻渗透现象”主线式情境教学实践

以“渗透现象”一节教学为例,在“海水稻”这一主线真情境中,学生经历“起境、承境、转境、合境”等情境的变化。在问题生成、任务驱动下,积极地进行了科学实验探索,培养批判性思维、创新思维等科学思维能力和社会责任意识。

Study on the Effect of Osmosis-regulating Substances and Organic Appendices on Somatic Embryogenesis in Wheat

[Objective] The study aimed to reveal the effect of osmosis-regulating substances and organic appendices on somatic embryogenesis in wheat. [Method] The suitable concentration combination of appendices was optimized by adding different concentrations of osmosis-regulating substances including mannitol, sorbitol and organic appendices such as Gln, CH and LH, into the somatic embryogenesis in wheat. [Result] The mannitol or sorbitol lower than 40 g/L was helpful for improving somatic embryogenesis; there was no significant difference in the induction rate of somatic embryogenesis when 300-500 mg/L Gln、CH or LH was respectively added into the induced medium, while somatic embryogenesis could be enhanced dramatically in the presence of 500 mg/L Gln together with 300 mg/L CH. [Conclusion] Somatic embryogenesis could be improved to some extent by different concentrations of osmosis-regulating substances and organic appendices, which laid foundation for establishing a more perfect system of somatic embryogenesis in wheat.

BWRO复合膜和SWRO复合膜的本质对比(英文)

采用均苯三甲酰氯和间苯二胺通过界面合法分别得到苦咸水反渗透复合膜和海水反渗透复合膜。两者在低盐浓度时,对氯化钠的脱除率相近;在高盐浓度时,苦咸水反渗透复合膜对氯化钠的脱除率明显低于海水反渗透复合膜。用扫描电镜、原子力显微镜分析两者表面形态发现海水反渗透复合膜表面粗糙度更小。X射线光电子能谱分析结果表明,海水反渗透复合膜表面的羧酸根含量更多。

反渗透海水淡化(SWRO)能量回收技术应用分析

反渗透技术已经在国内外的海水淡化工程中得到广泛应用,能量回收装置的应用使得反渗透海水淡化产水能耗大大降低,制水成本大幅下降。本文简要介绍了反渗透海水淡化能量回收技术及其经济成本分析,反渗透海水淡化能量回收装的分类,并对主流能量回收装置进行比较分析。SWRO系统中的流体能量回收利用技术有着良好的前景。

膜蒸馏技术用于垃圾渗滤液处理的研究进展与挑战

综述了膜蒸馏(MD)技术在垃圾渗滤液反渗透浓水处理及渗滤液原液处理方面的应用研究进展,从无机、有机、生物污染3个方面系统分析了MD技术用于工业化垃圾渗滤液处理所面临的膜污染问题,并进一步从污水预处理、抗污染膜材料组件开发和膜污垢清洗方面对MD技术用于垃圾渗滤液处理的膜污染控制进行了探讨与建议。

MICP纤维加筋优化电渗法加固软黏土的试验研究

目的为缓解传统电渗法加固软黏土过程中土体开裂和不均匀沉降等问题,改善软黏土的工程性质,提出微生物诱导碳酸钙沉淀(MICP)技术联合玄武岩纤维加筋优化电渗法处理效果。方法通过开展软黏土室内电渗模型试验,分析电渗过程中的排水量、电流强度和有效电阻,以及电渗处理后土体表面沉降量、含水率、抗剪强度和pH,结合SEM图像探究不同掺量的玄武岩纤维以及MICP-玄武岩纤维联合作用机制对电渗加固效果的影响机理。结果结果表明:(1)不同掺量的玄武岩纤维对电渗效果影响差异显著,纤维加入软黏土后可抑制电渗过程中的土体裂缝发展与电流衰减,掺量为0.4%的试验组最佳效果;(2)MICP技术与玄武岩纤维加筋的联合使电渗过程变得更加均衡与顺畅,有效改善了电渗固结排水导致的土体表面不均匀沉降;(3)在电渗过程中,MICP反应在土颗粒与纤维表面上生成的碳酸钙沉淀填充加固了土体,提升了土体强度均匀性;(4)MICP技术的加入在提升土体强度的同时减少了土体孔隙液的排出,降低了废液处理的压力,具有更高的环境适应性。结论该研究结果为提升电渗法加固软黏土地基的处理效果提供了新思路,拓展了加固软黏土方法新的可能性。

聚酰胺膜耐氯改性及氯化修复研究进展

介绍了间苯二胺-均苯三甲酰氯和哌嗪-均苯三甲酰氯两种典型的PA膜,深入剖析其最新的氯化破坏机理.在此基础上,进一步探讨了针对这两种膜的耐氯改性方法,包括改变单体结构、本体掺杂技术、物理涂覆方法以及化学接枝手段等.对PA膜氯化修复领域的最新研究进展进行了简要论述,包括初期氯化后的还原法修复和氯化降解后的修补剂修复.分析表明,耐氯PA膜的研制仍面临巨大挑战,PA膜的耐氯改性研究应在不牺牲其分离性能的前提下,综合考虑膜的其他各项性能,灵活运用各种改性方法.

Performance of Nanofiltration and Reverse Osmosis Membranes in Metal Effluent Treatment

The performance of different nanofiltration （NF） and reverse osmosis （RO） membranes was studied in treating the toxic metal effluent from metallurgical industry. The characteristics and filtration behavior of the processes including the wastewater flux, salt rejection and ion rejection versus operating pressure were evaluated. Then the wastewater flux of RO membrane was compared with theoretical calculation using mass transfer models, and good consistency was observed. It was found that a high rejection rate more than 95% of metal ions and a low Chemical Oxygen Demand （COD） value of 10 mg·L^-1 in permeate could be achieved using the RO composite membrane, while the NF rejection of the salt could be up to 78.9% and the COD value in the permeate was 35 mg·L^-1. The results showed that the product water by both NF and RO desalination satisfied the State Reutilization Qualification, but NF would be more suitable for large-scale industrial practice, which offered significantly higher permeate flux at low operating pressure.

Substrate matters:The influences of substrate layers on the performances of thin-film composite reverse osmosis membranes

Thin-film composite(TFC) reverse osmosis(RO) membranes are playing the dominating role in desalination.Tremendous efforts have been put in the studies on the polyamide selective layers. However, the effect of the substrate layers is far less concerned. In this review, we summarize the works that consider the impacts of the substrates, including pore sizes, surface hydrophilicity, on the processes of interfacial polymerization and consequently on the morphologies of the active layers and on final RO performances of the composite membranes. All the works indicate that the pore sizes and surface hydrophilicity of the substrate evidently influence the RO performances of the composite membranes. Unfortunately, we find that the observations and understandings on the substrate effect are frequently varied from case to case because of the lack of substrates with uniform pores and surface chemistries. We suggest using track-etched membranes or anodized alumina membranes having relatively uniform pores and functionalizable pore walls as model substrates to elucidate the substrate effect.Moreover, we argue that homoporous membranes derived from block copolymers have the potential to be used as substrates for the large-scale production of high-performances TFC RO membranes.

Investigation on removing recalcitrant toxic organic polluters in coking wastewater by forward osmosis

Investigation was made on the efficiency of two commercial membranes in removing via forward osmosis(FO)the low molecular weight organic compounds typical of coking wastewater. The membranes were supplied by Poten and HTI companies. The organics in the simulated coking water were indole and pyrridine. Under FO mode, the rejection to the organics by Poten membrane was around 50%, whereas that for HTI membrane was obviously higher, ranging from 65% to 74%. The response of the two membranes in terms of Water flux and reverse salt flux(RSF) towards changing feed/draw solution(DS) flow rates in FO mode showed similar tendency,but different degree. Generally, the flux in FO using HTI membranes was lower. For HTI membrane, FO operated with pressure retarded osmosis(PRO) mode was also performed and the overall rejection of the organics was slightly lower than that in FO mode. In the long term FO test within 15 days, both Poten and HTI membranes displayed flux reduction and rejection enhancement. But the variation with Poten membrane was much more obvious. Discussion was carried out about the reasons and the mechanisms behind the FO performance difference between two membranes and the variation in flux and rejection with operation conditions. Characterizations by SEM, FTIR, AFM, XRD and XPS were tried to support the proposed explanations.

Inhibition of CaCO_3 Scaling in Reverse Osmosis System by Zinc Ion

Scaling of reverse osmosis (RO) membrane surface is one of the main problems in desalination proc- esses. To mitigate scales, organic anti-scalants are often used. If the dosages of anti-scalants are reduced, by using other much cheaper scale inhibitors, RO running cost will decrease greatly. The present paper investigated the inhi- bition of CaCO3 precipitation by zinc ions in RO system. The results show that the zinc ion concentration of 2mg?L-1 was able to exert a marked suppression effect on both bulk precipitation of CaCO3 and on membrane scaling on waters of moderate hardness.

Study of reverse osmosis membranes fouling by inorganic salts and colloidal particles during seawater desalination

Fouling phenomenon is considered among the major reasons that cause significant increase of operating cost of desalination plants equipped with reverse osmosis(RO)membranes.This phenomenon is studied in the present work in the case of RO polyamide aromatic membranes using model seawater containing inorganic salts and colloidal compounds.Different solubility conditions of CaCO3 and CaSO4 were applied to study RO performances with and without colloid presence.During experiments,the membrane permeate fluxes were continuously monitored.Moreover,studies of chemical composition,structure,and morphology of the materials deposited on the membrane surface were conducted using energy dispersive microanalysis(EDS)X-ray diffraction and scanning electronic microscopy(SEM).Results show that in conditions of calcium carbonate oversaturation there is a reduction in the permeate flow of 11.2%due to fouling of the membrane by the precipitation of this compound.While in the same conditions of calcium sulphate oversaturation the reduction of the flow is 5%,so we can conclude that in conditions of oversaturation of both salts,calcium carbonate produces a greater fouling of the membrane that in its view causes greater decrease in the flow of permeate.All this based on the results of the test with both salts in oversaturated conditions.Resulting in the formation of calcite and gypsum crystals onto the membranes as XRD analyses stated.Additional presence of colloidal silica in those conditions intensifies strongly the fouling,leading until to 24.1%of permeate flux decrease.

Spontaneous imbibition characteristics of shale oil reservoir under the influence of osmosis

The spontaneous imbibition(SI)process in shale oil reservoirs is not only infuenced by capillary force,but also by the osmotic pressure between the fracturing fuid and formation water in the nanopores media.In this study,experimental methods are used to investigate the mechanisms of osmosis in the SI,taking into account the presence of initial formation water in shale oil reservoirs.To investigate the efect of osmosis,SI experiments were performed on the fne-grained felsic shale of the Qikou sag of Dagang oilfeld.Low-feld NMR testers and high-precision electronic balances are utilized for the measuring of oil–water migration.The results show that,when Sw≠0,high-salinity fuid SI can be divided into four stages:initial imbibition stage,drainage stage,secondary imbibition stage and stationary stage;when Sw=0,there is no drainage stage of high-salinity fuid SI;when Sw≠0 or Sw=0,low-salinity fuid SI can be called the“osmosis-enhanced SI”;and we have found that“newly formed pores or microfractures”as well as reducing salinity can promote SI.This article presents a systematic study of SI of shale oil reservoirs under the infuence of osmosis,which provide useful information for reservoir numerical simulation and development program design.

A Combined Forward Osmosis and Membrane Distillation System for Sidestream Treatment

Separate treatment of high-nutrient sidestream is an efficient and cost effective way to decrease the loading on the main plant, resulting in lower effluent nutrient concentration. This study investigated the use of a combined forward osmosis-membrane distillation (FO-MD) system for the removal of nitrogen present in high concentration in sidestream from anaerobic digestion process. The combined system was able to achieve almost 100% rejection of solids and acetic acid, and more than 98% rejection of NH3-N from the sidestream. The high rejection of NH3-N was mainly achieved by the FO process. The solids in the feed solution contributed to fouling problem in both FO and MD, resulting in significant decline in flux. However, 76% or higher flux recovery was achieved for FO membrane by cleaning with tap water. We observed that flux recovery was due to removal of solids from the membrane surface by the cleaning process. FO membrane also demonstrated excellent performance for continuous operation when cleaned for 15 min in every 24 h interval. Overall, the combined FO-MD system was found to be an effective solution for treatment of nutrient rich sidestream.

Studies on Feasibility of Reverse Osmosis (Membrane) Technology for Treatment of Tannery Wastewater

Tanneries reusing wastewater by combination of conventional and advanced Reverse Osmosis (RO) treatment technologies were assessed for technical and economic viabilities. Conventional treatment methods such as neutralization, clari-flocculation and biological processes are followed to clean the effluents before feeding to RO membrane modules. The characteristics of untreated composite effluents such as pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS), and total chromium were in the range of 4.00-4.60, 680-3600 mg/L, 1698-7546 mg/L, 980-1480 mg/L, 4200-14500 mg/L, and 26.4-190 mg/L, respectively. Inorganic ions like Ca2+, Na+, Cl– and SO42– were found more in the wastewaters. Conventional treatments significantly removed the organic pollutants however failed to remove dissolved inorganic salts. Membrane technology removed the salts as well as remaining organic pollutants and the product water is reused in the process. The studied tanneries (5 numbers) have achieved 93-98%, 92-99% and 91-96% removal of TDS, sodium and chloride, respectively. Seventy to eighty five percentage of wastewater was recovered and recycled in the industrial processes. The rejects are subject to either solar evaporation system or Multiple Effect Evaporation (MEE) technology. The resulting salts are collected in polythene bags and disposed into scientifically managed secured land fill (SLF) site. The cost of wastewater treatment for operation and maintenances of RO including the pre-treatments (conventional methods) is INR 100-110 m-3.

Recent advances in nanofiltration,reverse osmosis membranes and their applications in biomedical separation field

In the face of human society's great requirements for health industry,and the much stricter safety and quality standards in the biomedical industry,the demand for advanced membrane separation technologies continues to rapidly grow in the world.Nanofiltration(NF)and reverse osmosis(RO)as the highefficient,low energy consumption,and environmental friendly membrane separation techniques,show great promise in the application of biomedical separation field.The chemical compositions,microstructures and surface properties of NF/RO membranes determine the separation accuracy,efficiency and operation cost in their applications.Accordingly,recent studies have focused on tuning the structures and tailoring the performance of NF/RO membranes via the design and synthesis of various advanced membrane materials,and exploring universal and convenient membrane preparation strategies,with the objective of promoting the better and faster development of NF/RO membrane separation technology in the biomedical separation field.This paper reviews the recent studies on the NF/RO membranes constructed with various materials,including the polymeric materials,different dimensional inorganic/organic nanomaterials,porous polymeric materials and metal coordination polymers,etc.Moreover,the influence of membrane chemical compositions,interior microstructures,and surface characteristics on the separation performance of NF/RO membranes,are comprehensively discussed.Subsequently,the applications of NF/RO membranes in biomedical separation field are systematically reported.Finally,the perspective for future challenges of NF/RO membrane separation techniques in this field is discussed.

Energy Recovery Device with a Fluid Switcher for Seawater Reverse Osmosis System

Energy recovery device （ERD） is an important part of the seawater reverse osmosis （SWRO） desalination system. There are principally two kinds of ERDs, the centrifugal type and the positive displacement （PD） type. The PD type is of extensive concern and is preferred in large-scale plants. In this article, an innovative fluid switcher was presented and a two-cylinder hydraulic energy recovery unit with a lab-scale fluid switcher was set up. Tap water was used as the working medium instead of the actual seawater and brine in SWRO desalination plants. Under steady state operating conditions, the experimental results were obtained on the variations of the pressure and flow rate to and from the energy recovery unit. The hydraulic recovery efficiency （En） of the energy recovery unit with the fluid switcher reached up to 76.83%.