Conventional water resources in many regions are insufficient to meet the water needs of growing populations, thus reuse is gaining acceptance as a method of water supply augmentation. Recent ...advancements in membrane technology have allowed for the reclamation of municipal wastewater for the production of drinking water, i.e., potable reuse. Although public perception can be a challenge, potable reuse is often the least energy-intensive method of providing additional drinking water to water stressed regions. A variety of membranes have been developed that can remove water contaminants ranging from particles and pathogens to dissolved organic compounds and salts. Typically, potable reuse treatment plants use polymeric membranes for microfiltration or ultrafiltration in conjunction with reverse osmosis and, in some cases, nanofiltration. Membrane properties, including pore size, wettability, surface charge, roughness, thermal resistance, chemical stability, permeability, thickness and mechanical strength, vary between membranes and applications. Advancements in membrane technology including new membrane materials, coatings, and manufacturing methods, as well as emerging membrane processes such as membrane bioreactors, electrodialysis, and forward osmosis have been developed to improve selectivity, energy consumption, fouling resistance, and/or capital cost. The purpose of this review is to provide a comprehensive summary of the role of polymeric membranes and process components in the treatment of wastewater to potable water quality and to highlight recent advancements and needs in separation processes. Beyond membranes themselves, this review covers the background and history of potable reuse, and commonly used potable reuse process chains, pretreatment steps, and advanced oxidation processes. Key trends in membrane technology include novel configurations, materials, and fouling prevention techniques. Challenges still facing membrane-based potable reuse applications, including chemical and biological contaminant removal, membrane fouling, and public perception, are highlighted as areas in need of further research and development.
The installation of reverse osmosis (RO) desalination plants has been on the rise throughout the world. Thus, the estimation of their capital cost (CAPEX) is of major importance for governments, ...potential investors and consulting engineers of the industry. In this paper, parameters potentially affecting the direct capital costs of brackish water RO (BWRO) and seawater RO (SWRO) desalination plants, delivered through Engineering, Procurement & Construction (EPC) contracts, were assessed. The assessment was conducted based on cost data from 950 RO desalination plants contracted in the Gulf Cooperation Council (GCC) countries and in five southern European countries. The parameters assessed include plant capacity, location, award year, feed salinity, and the cumulative installed capacity within a region. Our results showed that plant capacity has the strongest correlation with the EPC cost. Plant type (SWRO or BWRO), plant award year and the region of the RO plant were also found to be statistically important. By utilizing multiple linear regression, a model was also developed to estimate the direct CAPEX (EPC cost) of RO desalination plants to be located either in the GCC countries or southern Europe, which was then verified using the k-fold test.
•Parameters affecting the direct capital costs of BWRO and SWRO plants were assessed.•Plants delivered through EPC contracts were considered.•Assessment was based on cost data from 950 RO plants in the GCC and southern Europe.•Plant capacity, type, award year, and region were found to affect RO CAPEX cost.•A model was also developed and verified for RO CAPEX estimation.
•Timeline of MD’s growth and development with major milestones.•Systematic map review of MD publications between 1960 and 2016.•MD practitioners’ survey on future application and research ...areas.•Alignment between MD researchers and industry for MD commercialization examined.
Research on membrane distillation (MD) experienced a slow growth from the 1970s through 90s but has gained revived interest recently. Despite recent developments, MD still has to overcome several hurdles to pave its path to successful commercialization. This article presents a systematic map review of all research publications available in the ScienceDirect database from 1970 to 2016 focusing on the key aspects of MD publication trends, applications, research topics and the studied membrane materials and configurations. The gathered information was compared with MD implementation trends to assess the alignment of academia and industry towards MD commercialization. A select group of MD experts, both from academia and industry, were then surveyed for their perspective on the future for MD commercialization. While desalination is the most studied MD application so far, brine concentration was unanimously identified as the most likely future application for MD. Industry experts believe topics of practical significance, such as fouling and wetting, deserve more research focus. On the contrary, improving energy efficiency in MD was the top pick by academic experts. The most researched topic, development of novel MD membranes, was at odds with the key research topics identified by the industry and research experts for MD’ growth and development.
Utilizing low enthalpy geothermal resources in various applications, including desalination, has triggered continuously growing interest in the past decade. This work offers a preliminary ...techno-economic evaluation of coupling a low-enthalpy geothermal resource, commonly found in regions such as the Arabian Gulf countries, and a suitable desalination technology. The desalination processes chosen, multiple effect distillation (MED) and reverse osmosis (RO), were designed as integrated energy–water systems and were compared and assessed in terms of their levelized cost of water produced. It was found that geothermal RO could potentially be a more cost-effective option for seawater geothermal desalination in the Gulf Cooperation Council (GCC) countries, based on our model results. A number of parameters, which can potentially alter the results of the analysis, were chosen to investigate their effect on the LCOW of the proposed schemes. These parameters include feed water quality, operational lifetimes of both the geothermal and desalination systems, quality of the geothermal resource, cost of well-drilling and finally, reinjection temperature of the utilized geofluid. By varying their values, the robustness of our initial model results was assessed.
•Techno-economic analysis of RO and MED using low enthalpy geothermal energy•A cost model was developed for estimation of the LCOW of each scheme.•RO is more cost-effective than MED when driven by the same geothermal source.•Sensitivity analysis conducted to study the effect of several parameters on LCOW•Quality and utilization efficiency of the geothermal resource affect LCOW the most.
•Low temperature sol-gel method was developed to functionalize polymeric membranes.•Vacuum, spray and sol gel coating were tested to make photocatalytic HF membranes.•Sol gel coating yielded higher ...permeability than spray and vacuum coating.•Membranes were carefully characterized to assess coating impact on their properties.•Coated membranes achieved 30–40% degradation of MB and CHD under solar light.
In this research, the degradation by heterogeneous photocatalysis of organic pharmaceutical waste compounds using TiO2 nanoparticles immobilized on polymeric commercial hollow fiber (HF) ultrafiltration membranes was studied. Three immobilization methods that were tested; spray-, vacuum- and sol-gel-coating. The latter was found most successful as it didn’t compromise the permeability of the membrane as much as the other two methods. The sol-gel coated membranes were characterized by multiple analytical techniques, such as Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD). The compatibility of the membrane components with the aqueous feed containing pharmaceutical waste compounds was confirmed using the Hansen solubility parameters. The effectiveness of TiO2-coated membranes was then assessed in the degradation studies of two organic compounds; Methylene Blue (MB) and Chlorhexidine Digluconate (CHD), serving as the model and the target pharmaceutical compound, respectively. Spray and vacuum coating were unsuccessful in obtaining a stable TiO2 coated membranes, whereas sol-gel coating yielded a stable TiO2 layer and hence was chosen for further optimization. The immobilization of TiO2 was confirmed by SEM images and Raman spectra. Degradation of more than 30 and 40% of MB and CHD, respectively, was achieved under filtration conditions with simulated solar light radiation.
Storing desalinated water within a strategic aquifer storage and recovery system has been identified as a potential cost-effective solution for the Gulf Council Cooperation (GCC) countries. In this ...study, we investigated a wind-driven reverse osmosis (RO) scheme to create fresh water for ASR. The ongoing Liwa ASR project in the United Arab Emirates (UAE) served as a case-study to assess the economic feasibility of the concept. As the RO plant is not destined to meet a real-time demand, its water production rate was allowed to vary, following a fluctuating wind power supply, thus avoiding the need for costly power storage. New generation wind turbines specifically designed to operate at low wind speed were investigated, which are better suited for the GCC. Sites were identified using Geographic Information System and the recently developed Wind Energy Resource Atlas of the UAE, followed by technical and cost analyses. Findings showed that the wind-driven RO scheme can be competitive with the current thermal desalination in the UAE. However, the avoidance of shut-down of a variable load RO plant hampers the effective use of the fluctuating wind power, resulting in increased plant capital costs due to plant over-sizing. Several scenarios were investigated in this regard.
•Wind-driven RO scheme was developed to create fresh water for ASR.•A cost model was developed for estimation of the LCOW of a variable-load RO.•Geographic feasibility analysis determined most suitable sites for wind-driven RO.•The LCOW was estimated to be in the range of USD $ 1.57–2.11 per m3.•The RO's CAPEX is the most important cost component in the cost breakdown.