Global Water Sustainability Research Articles

The Rise and Transfer of the River Chief System: A Review of Chinese Water Governance and Its Potential to Transfer to the Global Community

As a result of water sustainability issues, China has enacted a range of policies to improve its water ecosystem since the middle of the 20th century. These measures include the creation of the Seven River Conservancy Commissions, the development (combination and recombination) of ministries and departments to address environmental pollution and degradation, and recently, the implementation of the river chief system. Considering the importance of global water sustainability and the positive impact Chinese measures have had in this area, the author will examine if the river chief can be transferred to other political jurisdictions. To do this, the author gathered data using keyword searches of the Web of Science and Google Scholar, official government sites, media sites and key international organizations. Based on this, the author reviews the development of the river chief system in the context of broader ecological reforms, places the rise of the river chief in the context of potential lessons for future improvement, and speculates on the possibility that China could transfer the river chief to countries facing similar challenges in their water governance regimes.

Integration of coagulation–flocculation and photolysis processes for treating reverse osmosis concentrate (ROC) of pharmaceutical wastewater management

ABSTRACT This study provides novel insights into optimizing the integral treatment process, contributing to ROC treatment strategies. A comprehensive treatment approach for reverse osmosis concentrate (ROC) from pharmaceutical wastewater was investigated using an integral system consisting of a coagulation-flocculation and photolysis process. Ferric chloride (FC) and poly-aluminum chloride (PAC) are examined as coagulants within the range (0.1–1) gL−1, focusing on turbidity, chemical oxygen demand (COD), and total organic carbon (TOC) removal. The findings show that the optimal FeCl3 dosage is 0.4 gL−1, achieving significant turbidity reduction to 1 NTU. PAC at 0.2 gL−1 is optimal, reducing turbidity to 1 NTU and exhibiting non-linear behavior in COD and TOC removal, introducing them as a starting point to the post-treatment. Photolysis of treated samples at pH 7 yields COD reductions of 60.5% for PAC and 79.5% for FC, with respective TOC reductions of 79.5% and 75.23% over 360 min. At (pH 3.5) showed a significant reduction in the COD and TOC of treated ROC. The FC coagulant could decrease the COD from 261 to 5 mgL−1 (98% COD removal) and the TOC from 143.9 to 5 mgL−1 (74.8% TOC removal). The FAC coagulant could decrease the COD from 675 to 39 mgL−1 (93% COD removal) and the TOC from 186 to 13.1 mgL−1 (69.7% TOC removal). The conventional oxidant (H2O2) at optimal dosages enhanced COD and TOC removal at pH 7, with treated PAC and FeCl3 achieving 81.8% and 97.2% COD reduction and 89% and 98% TOC reduction at 360 minutes. These results were supported by the cost analysis in which this system was cost effective manner. This system can offer a solution for the efficient treatment of other types of industrial wastewater and open the door to new applications for water reuse on a broad scale, contributing to global water sustainability.

Optimizing energy efficiency in brackish water reverse osmosis (BWRO): A comprehensive study on prioritizing critical operating parameters for specific energy consumption minimization

Reverse osmosis (RO) systems offer a viable solution for treating brackish water (BW), a common but underutilized water resource. However, the energy-intensive nature of brackish water reverse osmosis (BWRO) systems poses affordability challenges to water supply, necessitating a focus on minimizing their energy consumption to support SDG6's goal of providing safe and affordable drinking water for all. This study addresses the critical need to minimize the specific energy consumption (SEC) of a typical BWRO system, defined as the energy consumed per unit of water recovered, mathematically and experimentally. Empirical models were developed proving there is a global minimum SEC while adjusting the operating conditions. Furthermore, we identified the key operating factors influencing SEC and their priority levels, along with their interactive effects. Notably, no prior study has discussed the significance and interaction of these operating factors (e.g., feed water salinity, temperature, pressure, flowrate and membrane permeability) on SEC of a BWRO system. Employing a full factorial experimental design with mixed levels of operating parameters, the study developed regression models that elucidate the mechanistic interaction between these parameters and system performance. Moreover, the models were validated experimentally, with a new dataset demonstrating their accuracy and reliability. ANOVA statistical analysis identified feed salinity, pressure, flow rate, feed flow rate×pressure, salinity×pressure, and temperature as influential operating parameters in reducing SEC, in descending order of importance. Operating within the determined optimum range resulted in a 36 % decrease in SEC and a more than fourfold increase in water recovery. The study's systematic approach and findings can be extrapolated to optimize the performance of other desalination technologies and diverse feed water types, contributing significantly to global water sustainability efforts.

Half of twenty-first century global irrigation expansion has been in water-stressed regions

The expansion of irrigated agriculture has increased global crop production but resulted in widespread stress on freshwater resources. Ensuring that increases in irrigated production occur only in places where water is relatively abundant is a key objective of sustainable agriculture and knowledge of how irrigated land has evolved is important for measuring progress towards water sustainability. Yet, a spatially detailed understanding of the evolution of the global area equipped for irrigation (AEI) is missing. In this study, we used the latest subnational irrigation statistics (covering 17,298 administrative units) from various official sources to develop a gridded (5 arcmin resolution) global product of AEI for the years 2000, 2005, 2010 and 2015. We found that AEI increased by 11% from 2000 (297 Mha) to 2015 (330 Mha), with areas of both substantial expansion, such as northwest India and northeast China, and decline, such as Russia. Combining these outputs with information on green (that is, rainfall) and blue (that is, surface and ground) water stress, we also examined to what extent irrigation has expanded unsustainably in places already experiencing water stress. We found that more than half (52%) of the irrigation expansion has taken place in areas that were already water-stressed in the year 2000, with India alone accounting for 36% of global unsustainable expansion. These findings provide new insights into the evolving patterns of global irrigation with important implications for global water sustainability and food security.

Case study of continental‐scale hydrologic modeling's ability to predict daily streamflow percentiles for regulatory application

AbstractRegulatory practitioners use hydroclimatic data to provide context to observations typically collected through field site visits and aerial imagery analysis. In the absence of site‐specific data, regulatory practitioners must use proxy hydroclimatic data and models to assess a stream's hydroclimatology. One intent of current‐generation continental‐scale hydrologic models is to provide such hydrologic context to ungaged watersheds. In this study, the ability of two state‐of‐the‐art, operational, continental‐scale hydrologic modeling frameworks, the National Water Model and the Group on Earth Observation Global Water Sustainability (GEOGloWS) European Centre for Medium‐Range Weather Forecasts (ECMWF) Streamflow Model, to produce daily streamflow percentiles and categorical estimates of the streamflow normalcy was examined. The modeled streamflow percentiles were compared to observed daily streamflow percentiles at four United States Geological Survey stream gages. The model's performance was then compared to a baseline assessment methodology, the Antecedent Precipitation Tool. Results indicated that, when compared to baseline assessment techniques, the accuracy of the National Water Model (NWM) or GEOGloWS ECMWF Streamflow Model was greater than the accuracy of the baseline assessment methodology at four stream gage locations. The NWM performed best at three of the four gages. This work highlighted a novel application of current‐generation continental‐scale hydrologic models.

Bias correcting discharge simulations from the GEOGloWS global hydrologic model

The Group on Earth Observations (GEO) Global Water Sustainability (GEOGloWS) hydrologic model provides global river discharge hindcasts and daily forecasts at approximately one million subbasins worldwide. The model is meant to sustainably provide discharge data during emergency situations and to underdeveloped countries which do not have sufficient local capacity. The primary model error is biased flow magnitudes which reduce the usefulness of the results. We applied a revised implementation of the SABER bias correction method to correct GEOGloWS model results. SABER uses a combination of watershed clustering with machine learning, geospatial analysis, and statistics to generalize bias patterns in gauged basins so they can also be applied to ungauged basins. We validated the bias corrected data created using the improved SABER method at 12,965 gauges globally and showed that this method reduced the mean error at 90% of gauges. We present an analysis of the improved SABER method using several metrics including mean error, root mean squared error, and Kling Gupta Efficiency. We found that the GEOGloWS model is usually biased high but our results indicate a reduction in the bias of the GEOGloWS model worldwide. We evaluate the varied performance of the bias correction procedure and significance of the improvements which vary based on stream order the watershed classifications derived in our analysis. We provide guidance on the use of bias corrected global data to local scale applications and discuss implications for the GEOGloWS model in the future.

Estimating the Impacts of Ungauged Reservoirs Using Publicly Available Streamflow Simulations and Satellite Remote Sensing

On the Korean Peninsula, the Imjin River is a transboundary river that flows from North Korea into South Korea. Therefore, human intervention activities in the upstream region can have a substantial impact on the downstream region of South Korea. In addition to climate impacts, there are increasing concerns regarding upstream man-made activities, particularly the operation of the Hwanggang dam located in the territory of North Korea. This study explored the feasibility of using the publicly available global hydrological model and satellite remote sensing imagery for monitoring reservoir dynamics and assessing their impacts on downstream hydrology. “Naturalized” streamflow simulation was obtained from the Group on Earth Observation (GEO) Global Water Sustainability (GEOGloWS) European Centre for Medium-Range Weather Forecasts (ECMWF) Streamflow Services (GESS) model. To correct the biases of the GESS-based streamflow simulations, we employed quantile mapping using the observed streamflow from a nearby location. This method significantly reduced volume and variability biases by up to 5 times on both daily and monthly scales. Nevertheless, its effectiveness in improving temporal correlation on a daily scale in small catchments remained constrained. For the reservoir storage changes in the Hwanggang dam, we combined multiple remote sensing imagery, particularly cloud-free optical images of Landsat-8, Sentinel-2, and snow-free Sentinel-1, with the area–elevation–volume (AEV) curves derived from the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). In assessing its hydrological impacts, the study found that overall impacts within the downstream catchment in Pilseung bridge of South Korea were generally less significant compared to the upstream Hwanggang catchment. However, there was a higher probability of experiencing water shortages during wet months due to the upstream dam’s operations. The study highlights the potential benefits of utilizing the publicly available hydrological model and satellite remote sensing imagery to supplement decision makers with important information for the effective management of the transboundary river basin in ungauged regions.

Micro-hydropower systems for smallholder farmers in rural communities of Taraba state, Nigeria: Feasibility study, system analysis, design and performance evaluation (Part II)

This article deals with the feasibility study, system analysis, design, and performance evaluation of micro-hydropower systems for smallholder farmers in rural communities of Taraba state in Nigeria. The hydrologic data used to determine the available flow rate to produce the required hydraulic power were obtained from GEO Global Water Sustainability (GEOGloWS) Service. The principle of Darcy and Weisbach, applied in the Colebrook and Haaland’s equations were employed to analytically estimate the hydraulic head loss due to friction in the penstock, installed trash rack, and fitted valves. The Hydro-Power Plant (HPP) Design professional tool was used to size the different constituents of the proposed micro-hydropower plant, and to evaluate its overall performance. With a low net head of 5.2 m, and a maximum discharge of 1.21 m3/s, two vertical Kaplan turbines with combined peak power of 106 kW were obtained. The Kaplan turbines drive two 6-pole, 50-Hz asynchronous generators with nominal power of 50 kW each. The simulation results from the HPP design tool show that the system achieved a minimum efficiency of 56% with the flow ratio of 0.2, and maximum efficiency 86.1% with flow ratio ranging from 0.6 to 0.8. The Renewable Energy Project Analysis Software (RETScreen) Expert was utilized to perform cost, cash flows, financial sensitivity, and risk analysis of the proposed micro-hydropower plant in Wurno-Gassol. The RETScreen Expert estimated the risk level is at 10%, with minimum and maximum levels of confidence on risk associated with equity payback to occur in 4.6 years and 13.2 years respectively, with median level of confidence in year 7.2. Furthermore, the risk level on energy production cost is estimated at 10%, with minimum and maximum levels of confidence sitting at 101 USD/MWh and 140 USD/MWh respectively, with the median level of confidence at 118 USD/MWh.

A data‐oriented strategy to support water resource managers and researchers

AbstractGiven the wide diversity of data services provided to national water management agencies, the Group on Earth Observations (GEO) in collaboration with the Committee on Earth Observation Satellites (CEOS) developed the approach described in the report, Implementing the GEOSS Water Strategy—From Observations to Decisions to develop more coherent and equitable data services for water management through the use of Earth observations. Among other water resource issues, it recognized the need to enhance data‐enriched water management services to support decision making related to drought monitoring, flood warning, tracking and improving sustainable development and monitoring and ameliorating the impacts of climate change. Needs associated with the Strategy's four themes: improved data acquisition for essential water variables, research and product development, interoperability and coordination, and capacity development and decision support, are reviewed. Responses to the recommendations have been undertaken by GEO, led by its Global Water Sustainability (GEOGloWS) initiative which includes NASA contributions, CEOS, and the Global Terrestrial Network for Hydrology (GTN‐H). Progress on the themes is reviewed and benefits of these developments for international and US water management are identified. The commentary concludes with a summary of what has been achieved, what remains to be done, and the priority focus areas for implementation in the final year of the Strategy.

Advancing global hydrologic modeling with the GEOGloWS ECMWF streamflow service

AbstractMost people face some level of water insecurity. Wise water management practices to address water security issues typically require data derived from a combination of observation and model data. This data has historically proven difficult to sustainably supply in many areas of the world. We present the design and development of a global, modeled streamflow data source for the Group on Earth Observation (GEO) Global Water Sustainability (GEOGloWS) implemented at the European Centre for Medium‐Range Weather Forecasts (ECMWF). This GEOGloWS ECMWF Streamflow Service (GEOGloWS Service) is a solution and prototype to sustainably address this need for data. The GEOGloWS Service centralizes computing and human resources to build a global hydrologic model and exposes data and mapping web services that allow users to consume the resulting data to meet their specific needs. The global hydrologic model produces global 15‐day ensemble streamflow forecasts and a historical simulation since January 1979. We present case studies in several countries and research environments which demonstrate the utility of the approach taken by the GEOGloWS Service. The case studies show how the global modeled data are being applied to make informed decisions and advance projects in ways that otherwise would not have been possible.

Toward a better understanding of virtual water trade: Comparing the volumetric and impact-oriented virtual water transfers in China

The scarcity and spatial mismatch of water resources exert increasing pressure on global water sustainability. Interregional virtual water transfer through trade can alleviate or aggravate pressure on water resources because of the heterogeneity in regional water endowments. However, previous studies have mainly focused on volumetric virtual water transfers without considering actual impacts on local water resources. This study compares the volumetric and impact-oriented water footprints (WFs) in China in 2012 and 2015 using a multiregional input–output model (MRIO). Unlike the volumetric WF, which focuses on the volume of water used, the impact-oriented WF refers to the potential environmental impacts of water withdrawal in view of water availability. The results show a clear gap between the pattern of the volumetric virtual water flow and that of the impact-oriented virtual water flow. As a water-scarce region, North China imported 23824×106 m3 and 12338×106 m3 of volumetric virtual water from other regions in 2012 and 2015, respectively, but exported a large amount of impact-oriented virtual water to almost all other regions. Additionally, most water-rich regions transferred water scarcity risk as virtual water importers to water-scarce regions. For example, the largest net impact-oriented virtual water flows in 2012 (4421×106 m3 H2Oeq) and 2015 (4014×106 m3 H2Oeq) were from North China to East China. Our results highlight the importance of simultaneously considering both the volume and the impact of water use in virtual water trade analyses. Understanding these mechanisms is essential for helping to identify the actual receivers of water scarcity risk in virtual water trade network and develop sustainable virtual water strategies.

Materials Innovation for Global Water Sustainability

ADVERTISEMENT RETURN TO ARTICLES ASAPPREVEditorialNEXTMaterials Innovation for Global Water SustainabilityYouhong Guo*Youhong GuoMaterials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States*E-mail: [email protected] (G. Yu).More by Youhong Guohttps://orcid.org/0000-0003-3118-7878 and Guihua Yu*Guihua YuMaterials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States*E-mail: [email protected] (Y. Guo).More by Guihua Yuhttps://orcid.org/0000-0002-3253-0749Cite this: ACS Materials Lett. 2022, 4, XXX, 713–714Publication Date (Web):March 20, 2022Publication History Published online20 March 2022https://doi.org/10.1021/acsmaterialslett.2c00187Published 2022 by American Chemical SocietyRIGHTS & PERMISSIONSArticle Views409Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (392 KB) Get e-Alerts Get e-Alerts

Tethys App Store: Simplifying deployment of web applications for the international GEOGloWS initiative

Portability of web applications between web servers of different organizations can be challenging and can complicate sharing and collaborative use of such tools. Given the distributed nature of the web, this lack of portability is usually not a concern because a user in one organization can link to and use a web application hosted by another organization. However, access control or differentiation may be needed by an organization in terms of area of interest, input data, analytical techniques, access control, presentation, branding, and language. This is true for many government organizations, and their associated web sites, and servers. In such cases, there are compelling political, branding, security, and privacy motivations that require each organization or agency to host and manage web applications on their own servers rather than using third party web sites over which they have little or no control. We present the design, development, and testing of a system for discovering, installing, and configuring environmental analysis web applications on localized web servers. The system works with applications developed using Tethys Platform, which is an open-source software stack for creating geospatially enabled web-based applications. The developed Tethys App Store includes a Tethys application user interface that allows a server manager to retrieve applications from the central repository and install them on a local server with relative simplicity, similar to the installation of a mobile application to a mobile device from a mobile application store. The system was developed to support deployment of water and environmental analysis web apps for the international Group on Earth Observations (GEO) Global Water Sustainability (GEOGloWS) initiative of the National Aeronautics and Space Administration (NASA) and several partner organizations.

Predicting Disasters Using Global Water Intelligence

Accurate knowledge of the water cycle is essential for predicting disasters such as floods and droughts. However, it’s not easy to obtain good information from traditional weather and water forecasts. The Group on Earth Observations Global Water Sustainability initiative (GEOGloWS) provides hydrologic forecasts through an accessible web service to assist local water users. Partnering with water scientists worldwide, Professor Jim Nelson of Brigham Young University worked with the European Centre for Medium-Range Weather Forecasts to develop a global streamflow service. This service provides local communities with actionable water intelligence, enabling them to focus on solutions to water-related problems.

Extended field investigations of ozone-biofiltration advanced water treatment for potable reuse

Recovering and reusing treated wastewater effluent is a sustainable and cost-effective practice for addressing global water sustainability. To date, most potable reuse advanced water treatment (AWT) solutions are based on reverse osmosis (RO), which generates a continuous reject stream of concentrated brine waste. Ozone-biofiltration based solutions have been investigated as a potential alternative for RO. However, implementation of ozone-biofiltration for potable reuse projects around the world has been limited. The goal of this study was to conduct an extended field investigation of ozone-biofiltration treatment to address regulatory, design, and operational hurdles that may hinder implementation in water-short areas. For 16 months, two parallel biological activated carbon (BAC) filters were operated at empty bed contact times (EBCTs) of 10 min and 20 min treating up to 60,000 and 30,000 bed volumes (BVs), respectively, of sand filtered effluent from a municipal wastewater treatment process. BAC 1 (EBCT = 10 min) and BAC 2 (EBCT = 20 min) used Calgon Filtrasorb 400 granular activated carbon (GAC) as filter media, with equal bed depths of 0.8 m. Increasing the specific ozone dose from 0.9 to 2.0 provided a muted response with respect to oxidation of contaminants of emerging concern (CECs) that are resistive to ozonation. N-Nitrosodimethylamine (NDMA) was generated during ozonation, with the average concentration of NDMA in ozonated effluent being 40.4 ng/L. In BAC 1 (EBCT = 10 min), NDMA was fully removed during the first month of study (<2000 BVs), partially removed between 2000 and 20,000 BVs, and completely removed when monitored between 57,000 and 62,000 BVs. These trends clearly reveal time-dependent interactions between carbon-based (e.g., adsorption) and non-carbon-based (e.g., biodegradation) removal mechanisms. In BAC 2 (EBCT = 20 min), almost all CECs, excluding NDMA, were removed consistently throughout the study (through ∼30,000 BVs). This indicates a somewhat different interaction between carbon-based and non-carbon-based removal in the more lightly loaded BAC 2, compared to BAC 1. After 482 days of operation, BAC 1 (EBCT = 10 min) produced effluent with lower NDMA concentration (<2 ng/L) than BAC 2 (10 ng/L), confirming prior evidence of cometabolic NDMA biodegradation pathways operable in more heavily loaded BACs. These findings emphasize the need for extended field testing (50,000 BVs or greater). BAC 1 removed TOC in effluent until it plateaued at around 6 mg/L after 60,000 BVs, whereas BAC 2 effluent plateaued at around 4 mg/L. Under plateau conditions, BAC 1 and BAC 2 with sand filter pretreatment and ozonation appear to have a gross TOC removal potential of around 0.2–0.3 kg of TOC removed per day per cubic meter of carbon media (kg/d/m3). A comparative analysis of findings from this study and results from a past ozone-BAC study in the Reno area (termed BAC 3 operated downstream of membrane filter with an EBCT of 30 min) shows that higher TOC removal was observed in BAC with shorter EBCT and upstream sand filter compared to BAC with longer EBCT and upstream membrane filter. The present study addresses the regulatory and financial concerns associated with ozone-BAC performance in potable reuse applications. Improved comprehension of ozone-BAC performance, coupled with its reduced capital and operations and maintenance (O&M) costs compared to RO, may accelerate the full-scale implementation of ozone-BAC treatment as a sustainable solution for the rapidly emerging potable reuse market.

Seasonal dynamics of cyanobacteria and eukaryotic phytoplankton in a multiple-reservoir recycling irrigation system

BackgroundAgricultural runoff recycling systems are manmade aquatic ecosystems of growing significance to global water sustainability, crop health, and production. This study investigated the seasonal dynamics of microbial community in a three-reservoir recycling irrigation system with a stepwise water flow and compared with that of an adjacent runoff-free stream. Runoff water from all production areas was captured in a sedimentation reservoir which overflowed to a transition reservoir then retention reservoir through a culvert. Stream water was pumped to replenish the reservoirs as needed during growing seasons.Results16S rDNA PCR clone libraries of quarterly water samples from three reservoirs and one stream were sequenced, and 575 operational taxonomic units (OTUs) were identified and assigned to cyanobacteria, eukaryotic phytoplankton, and other bacteria. When compared to the stream, three reservoirs consistently had low microbial diversity. A distinct seasonal pattern of microbial community structure was observed for each reservoir and the stream. Stream was consistently dominated by other bacteria. Retention reservoir was dominated by cyanobacteria during the summer and fall and eukaryotic phytoplankton during the winter and spring. Sedimentation reservoir was dominated by cyanobacteria beginning in the spring but that dominance was altered when water was pumped from the stream from early spring to fall seasons. Transition reservoir had the greatest shift of microbial community structure, being dominated by other bacteria in the summer, cyanobacteria in the fall, and eukaryotic phytoplankton in the winter and spring. Water temperature and ammonium level were the two most important contributing factors to the seasonality of microbial community in these reservoirs.ConclusionsThe three recycling irrigation reservoirs consistently had lower microbial diversity and distinct community structure when compared to the stream. These reservoirs were typically dominated by cyanobacteria during warm seasons and eukaryotic phytoplankton during cool seasons. This seasonal pattern was altered when water was pumped from the stream. The cyanobacteria dominance was associated with rising water temperature and ammonium level. These results highlight the importance of preventing agricultural runoff from entering natural waterways and water resources and provide a useful framework for further investigations into the ecological processes of this emerging ecosystem.

Field evaluation of membrane distillation technologies for desalination of highly saline brines

Membrane distillation (MD) is a hybrid thermal-membrane desalination process that uses low-grade waste heat and hydrophobic membrane to produce high quality distillate. The MD process can treat highly saline brines that other conventional desalination processes cannot treat. These unique features of the MD process make it an ideal candidate to desalinate concentrated brines from thermal desalination plants to augment fresh water production from existing facilities.A consortium consisting of ConocoPhillips Global Water Sustainability Center, Qatar University, and Qatar Electricity & Water Company was formed to evaluate the application of MD for the desalination of concentrated brines from thermal plants. Five different MD technologies were evaluated and the two most suitable technologies were selected for field-testing. The pilot units A & B are based on multi-effect vacuum and air gap MD technologies, respectively. These units were tested side-by-side at a full-scale thermal desalination plant in Qatar. Pilot unit A showed a stable flux of 6.2LMH under optimized conditions with excellent salt rejection (>99.9%). Pilot unit B achieved a distillate flux of 2.5LMH and salt rejection greater than 98.9%. Overall, MD was shown to be a feasible technology to produce potable quality water from the brines discharged from thermal desalination plants.

Screening of advanced produced water treatment technologies: overview and testing results

Produced water (PW) is the highest volume liquid waste stream generated by the petroleum industry. Historically, the treatment of PW has been limited to free oil and suspended solids removal, using physical separation technologies, and injection in disposal wells. However, because of new regulations combined with geological restrictions and water scarcity, the drive to have greater fraction of the PW more extensively treated and ultimately reused is increasing. This paper presents the results of laboratory investigations carried out by the ConocoPhillips Global Water Sustainability Center, where various treatment processes (membrane processes, membrane bioreactors, membrane distillation and ozonation) were evaluated as treatment methods for PW from different oil & gas fields. The preliminary results of investigations performed confirmed the potential of Membrane Filtration, MBRs and Ozonation to treat PW and produce an effluent suitable for reuse. Membrane distillation may have potential in the longer term.

Application of Membrane Distillation for desalting brines from thermal desalination plants

Membrane Distillation (MD) is a hybrid thermal-membrane process that can use low grade waste heat to generate a vapor pressure difference across a hydrophobic membrane to produce a high quality distillate from concentrated brines. The MD process presents several benefits compared to Reverse Osmosis (RO) including: superior product water quality; ability to treat high salinity brines, and potentially lower capital & operating costs. These unique features of the MD process make it an ideal technical solution to desalinate brines from thermal desalination plants to increase fresh water production in the Arabian Gulf region.This paper evaluated the feasibility of using MD technology to desalinate brines from thermal desalination plants. A state-of-the-art MD bench scale unit was built and the performance of different MD membranes was compared under various operating conditions using synthetic saline solutions, brine from a thermal desalination plant and seawater from the Arabian Gulf. Overall, MD was shown to be a feasible and effective process capable of consistently producing high quality distillate (conductivity <10μS/cm) from high salinity brines (70,000mg/l TDS) from a thermal desalination plant. A consortium consisting of the ConocoPhillips Global Water Sustainability Center (GWSC), Qatar University (QU) and Qatar Electricity & Water Company (QEWC) was formed to operate pilot-scale MD systems to desalinate brines from a full-scale thermal desalination plant in Qatar to determine process economics and address specific field conditions of the region.

Application of membrane distillation to produce freshwater from high salinity brines

Background: In Qatar, the production of freshwater is achieved by thermal desalination combined with power plants. This means that both hot concentrated brines and low grade waste heat are potentially available. Membrane distillation (MD) is a hybrid thermal membrane process that can use low grade waste heat to generate a vapor pressure difference across a membrane and therefore produce a high quality distillate from high salinity brines. The unique features of the MD process make it an ideal technical solution to increase freshwater production in Qatar. Objectives: The main objectives of the project are to investigate the suitability of the MD technology under conditions in Qatar and address scale-up and process optimization issues using real brines from a local thermal desalination plant. The project is a partnership of ConocoPhillips Global Water Sustainability Center at Qatar Science & Technology Park, Qatar University, and Qatar Electricity and Water Company. Results: Phase 1 - bench scale testing: T...