Existing and the future planned desalination facilities in the Gaza Strip of Palestine and their socio-economic and environmental impact

The present study analyzes the economic viability of an Integrated Energy System (IES) that couples a Reverse Osmosis (RO) water desalination facility with a Nuclear Power Plant (NPP). The case study is conducted in collaboration with Arizona Public Service (APS), the operating owner of the Palo Verde Generating Station (PVGS) NPP. A challenge APS is facing is that their cooling water acquisition contract with the Sub Regional Operating Group (SROG) will expire soon and a renewal can only be done for a significantly higher price of the water. Therefore, APS is seeking alternative sources for their cooling water. One opportunity is to pump brackish water from the regional ground water. Although much less expensive than the water from the new SROG contract, the salinity of the brackish water is so high that a blend of brackish and SROG water will need additional treatment to improve its quality for use in the PVGS cooling towers. A study has been conducted in 2018 at Idaho National Laboratory (INL) to investigate the economics of an PVGS onsite RO desalination plant that would reduce the salinity of a SROG and brackish water blend to an acceptable level. One of the main findings of that study was that the overall economics of water desalination can be greatly improved if, in addition to cooling water for PVGS, potable water could also be produced and sold for profit. In fact, the study concluded that only producing cooling water for PVGS via RO desalination is not economically viable compared to buying all needed cooling water from the SROG. The present report investigates the economic impact of a large, regional RO desalination plant that could provide potable water for the region, considering the conclusions from last year’s scoping study. The study looks in particular at the water-market situation in the West Valley of Phoenix; i.e., in the area of the municipalities of Buckeye, Goodyear, Avondale and Tolleson. In addition to providing potable water for the adjacent municipalities, the concentrate from the regional RO plant would be taken and treated by PVGS to provide some cooling water for a (hopefully) lower cost than that of the SROG water. Furthermore, a cost structure could be put in place for the treatment of the concentrate from the regional RO that would offset some of the water acquisition cost for APS. The analysis used the Nuclear-Renewable Hybrid Energy System (N-R HES) software framework, which was developed at INL in 2016. The framework has reached some level of maturity, such that it can be applied to more than simple demonstration cases; i.e., real industry problems. The analysis in this report considers two cases (for various scenarios): First, the Base Case is the most economic one for APS, as no RO is built, i.e. the case for which cooling water acquisition and treatment cost are lowest. The 2018 INL study showed that some brackish water can be blended with the effluent SROG water without having to build the onsite RO. The Base Case is where APS pumps the maximum volume of less-expensive brackish water (limited by water chemistry in the cooling towers), blends it with the effluent from the SROG, and no RO is built. Second, the proposed RO Case includes two RO plants, one onsite at PVGS and another larger, regional one close to the brackish water wells. The regional RO produces potable water that is sold to the regional municipalities, while the PVGS RO onsite treats (part of) the regional ROs' concentrate and brackish water blend. The desalinated water from the PVGS RO is used in the cooling towers at PVGS. The analysis evaluates the difference in economics, using the Net Present Value (NPV) and Internal Rate of Return (IRR), between the cases. By comparing the two cases, in addition to evaluating the economics of the regional RO, we can also assess the impact of the regional RO on PVGS and consequently APS economics. The study shows that (for the Base Case) to offset the treatment cost for the RO concentrate, the cost of concentrate treatment to be paid by the regional RO to APS would be between 5 – 35 $/m3 of concentrate (depending on the regional RO size envisaged). Correspondingly, the Levelized Cost of Potable Water (LCOPW), which is the average or unit cost, for the regional RO is in the 0.55 – 0.6 $/m3 range of potable water. Or, considering the residential water demand model developed for the Phoenix West Valley, the NPV of the regional RO would be between $20 and 100 billion.

A theoretical analysis on upgrading desalination plants with low-salt-rejection reverse osmosis

Brine salty water that is produced from Reverse Osmosis desalination plants usually has very large quantity and contains much higher salts ratio than that found in the sea. The disposal of such brine water has risks on environment. The objective of the research is to investigate the best brine disposal option in Gaza Strip. Five options for the disposal of brine were studied: 1) disposal of brine to the sea; 2) discharge of brine to wastewater plant; 3) deep well injection; 4) evaporation pond and 5) land irrigation. The new desalination plant Short-Term Low Volume (STLV) of a capacity of 6000 m3/d was used as a case study. Initially, the cost for each option was calculated separately, where it was found that the least cost is to pump the brine to the sea without affecting the seawater and marine life. To support this decision, two methods were used to reach the optimal option for the disposal of brine: Multi-Criteria Analysis (MCA) and Analytic Hierarchy Process (AHP). In MCA the measurement includes: economic, environmental, technical, political and social aspects, depending on a group of academics and experts in that field to fill in the questionnaire, which is a part of the analysis. As a result of that, the highest percentage among other options goes to pump the brine directly to the sea. On the other hand, the second method, which is Analytic Hierarchy Process (AHP), used the method of matrices among the different options and linked it with the standards that have been selected in the first method (MCDA). AHP method indicated also the best disposal of brine by pumping the brine to the sea.

Brine disposal from reverse osmosis desalination plants in Oman and the United Arab Emirates

Water quality evaluation of small scale desalination plants in the Gaza Strip, Palestine

Saline groundwater is the primary water source for agricultural development in the United Arab Emirates (UAE). Many small-scale reverse osmosis (RO) desalination plants have been installed to desalinize saline groundwater for use in irrigating vegetables (mainly in green houses), forages, date palm and fruit trees. Twelve plants in inland areas and three plants in coastal areas were studied to evaluate the existing brine disposal practices. The capacity of ROs varied from 28 to 325 m3 d-1. Pre-treated brackish groundwater, salinity varying from 4 to 37 dS m-1, was used as feed water. Higher groundwater salinity was observed in coastal areas due to sea-water intrusion. Chemical analysis of brine and soils at the disposal sites showed trace existence of heavy metals. The methods of brine disposal include (i) surface disposal (to excavated/non-excavated pits or mountain terrain or steep edge of sand dunes), (ii) well injection or dug well, (iii) pipeline discharge to sea beach, (iv) irrigation of salt-tolerant plants or blending brine with feed water for irrigating date palm, (v) use in cooling pads of green houses, and (vi) discharge to wadi beds. Among the disposal methods, surface disposal and dug well near the RO plants are critical as feed water can be further polluted by brine and chemicals used in the desalination process. These disposal practices could be replaced by environmental friendly methods such as non-leaking evaporation ponds and biosaline agriculture.

Capital cost estimation of RO plants: GCC countries versus southern Europe

Seawater desalination is a vital source of drinking water, especially in coastal and remote areas. However, its sustainability is constrained by the high energy requirement. The need for fresh water supplies continues to rise due to its intensive use in many development sectors, such as agriculture and industry, as well as the continued increase in population. This has led to the idea of using nuclear power in seawater desalination to reduce the stress on the main electrical grid and enhance sustainable. The paper's goal is to optimize a reverse osmosis (RO) desalination plant to produce 100,000 m3 of fresh water daily. The best membrane is selected by testing 10 FilmTec membranes, with a focus on achieving optimal product quality (TDS) while maintaining an acceptable level of specific energy consumption (SEC). The study aims to address the challenge of delivering potable water by designing and modeling a standalone desalination plant powered by small modular reactors (SMRs). According to ROSA's analysis, the optimal RO desalination unit consists of two stages with a total of 175 membranes. The FilmTec SW30XHR-400 is identified as the best option based on superior water quality. This membrane has a specific energy consumption of 5.17 kWh/m3 and a low TDS of 141.4 mg/L. The total power consumption of the RO plant is approximately 21.5 MW; therefore, the KAREM-25 MWe reactor has been selected to be coupled with the RO desalination plant.

With a reverse osmosis (RO) desalination plant designed to satisfy only the contracted-for water supply, the water company would be missing out on potential benefits that could have been obtained selling water in periods of high demand. On the other hand, sizing the RO desalination plant to produce water to satisfy peak demand means incurring additional costs as well as having the plant partially idle during periods of average or low demand. A model was developed using Excel macros to perform dynamic programming to optimize the capacity expansion of an RO desalination plant. The objective function is to maximize the present value of the total net benefits over the lifetime of the RO desalination plant. The model can be used to test different scenarios to capture time-variant tourism demand and price uncertainties on investment decisions. This study focuses on tourism dominated arid coastal regions, using Sharm El Sheikh (Sharm) in South Sinai, Egypt, as an example.19 RO plants in Sharm were surveyed and data were collected including unit production costs, O&M costs, energy consumption rates, contracted-for water supply, and utilization. Unit production cost of an RO desalination plant varies according to the degree of operation of the plant. This fact has to be taken into consideration when calculating the costs of RO desalination and when deciding on the plant capacity in order to maximize the total net benefit. Using the collected data, cost functions were developed for O&M costs as a function of utilization and plant capacity. The cost model calculated similar values to the actual total net benefit for one of the surveyed RO plant taken as an example. Using the optimization model, the maximum total net benefit is obtained with a smaller installed capacity than the actual case. A modified pricing structure is suggested in the paper that ties the water selling price to consumption in an effort to reduce demand in excess of contracted-for water supply aiding the water company to fulfill its contractual commitments to all users. However, price elasticity has to be taken into consideration to determine the impact of price change on water demand.

We are continually inundated with news and views about the demand for water outpacing supply. Our unsustainable development along rivers that do not reach the sea, declining ground water levels, damage to wetlands, high costs associated with acquiring new sources of water, and potential shortages related to global climate change are common news items. In most developed economies, there is little or no unallocated fresh water left to exploit. So, the question becomes: Where do we find “new” water for our burgeoning population? The answer may lie in the treatment of both shallow, brackish ground water and postconsumer water. Recent advances in reverse-osmosis membranes have reduced operational costs and established a linear correlation between total dissolved solids and operational cost of desalination; thus, there is increased interest in brackish water as input source. In the Southwest, the El Paso, Texas, Water Utilities Public Service Board recently dedicated a 100 million L/d desalination plant. Surprisingly, Florida with its high rainfall of more than 100 cm a year and many lakes and rivers is commonly thought of as a water-“rich” state; yet it has more water desalination plants than any other state: the city of Tampa Bay has the largest active desalination plant in the United States and uses brackish water from Tampa Bay. It is estimated that the state of New Mexico contains 16,000 billion m3 (13 billion acre-feet) of shallow brackish ground water (total dissolved solids greater than 500 mg/L and less than sea water, which is 35,000 mg/L). I suspect that development of brackish water aquifers would, in general, have less impact on the ecology than development of fresh water aquifers. That being said, we know little about the extent and chemistry of brackish water aquifers and almost nothing about their boundary conditions. Thus, I propose a federal 10-year sunset assessment of 1‰ per 250 gallons on all the ground water that municipalities extract, or about $1.00 each year for the average household using ground water. It is envisioned that this study would quantify the regional hydrology of these aquifers following the USGS’s Regional Aquifer System-Analysis model for fresh water aquifers. It would also identify any potential deeper formations capable of sequestering desalination concentrate. This small investment coupled with reduced consumption from increased rate changes and conservation measures such as low-flush toilets, low-flow showerheads and watering restrictions will prolong our existing resources and give us time to install the necessary infrastructure. We need to wean ourselves from our “once through, throw it out” philosophy that dominates current water resource management. We also need to reframe the linguistic argument away from “sewerage” or “waste water” toward the more societally acceptable “postconsumer” or “surplus municipal water.” (Remember, it is not a “used” car, it is a “previously owned” car!) Cities will soon no longer have the luxury of passing their used municipal water downstream. “Dilution is the solution to pollution” is a dated and unfair concept of passing water quality problems to the aquatic environment and cleanup expenditures to downstream users. Newly engineered membranes in desalination plants are excellent at removing not only salts but also pharmaceuticals, endocrine disruptors, prions, and other undesirable products left untouched by conventional waste treatment facilities. Combining membrane-treated water with aquifer storage and recovery (ASR) offers some interesting water management possibilities. That is, by recharging refreshed water, which is generally of better quality than native ground water, into aquifers, one can control the blending ratio of refreshed to native ground water in producing well fields. Furthermore, the aquifer provides a unique environment to adjust the temperature and chemistry and continue filtering the recharged water, adding insurance against the transport of many undesirable contaminants. Desalination and ASR are, however, energy-intensive processes; thus, greenhouse gas–free energy is likely to be integrated in any future energy scenario. Currently, approximately 28% of all electrical power generated in the United States is greenhouse gas–free (nuclear 19.3%, hydro 6.5%, biofuels 1.6%, wind less than 1%, and solar less than 1%), so these are likely to be the energy sources for desalination. Because both the membrane and the ASR technologies are mature and well established, development of new water from brackish ground water and postconsumer water could be a rapid and straightforward resolution to many of the domestic and industrial demands of our nation’s water resources well into the future.

A<scp>uthors</scp>’ R<scp>eply</scp>

Due to the continuing growth in RO desalination plants and the finite lifespan of the RO membranes, large stocks of the end-of-life (EoL) RO membranes are discarded to landfills. This has become a critical challenge in the RO desalination industry. The overall objective of this study was to validate the possibility of direct reuse of the end-of-life seawater reverse osmosis membranes (EoL SWRO) for brackish water desalination in order to limit the environmental impact of their disposal. This study investigates the membrane performance and characterization of four SWRO modules (EoL-M1, EoL-M2, EoL-M3, and EoL-M4). The hydraulic performance of the old membranes was assessed using 5,000 ppm synthetic (NaCl) brackish water and real brackish water, and was compared with the performance of two commercial membranes, namely brackish water RO membrane (BW30) and nanofiltration membrane (NF90). 84-92% NaCl rejection was achieved by direct reuse of EoL membranes, which was higher than the rejection characteristics obtained using commercial BW30 and NF90 membranes. Removal of common salts represent in natural water sources (Na2SO4, Mg2SO4 and MgCl2) and humic substances was also investigated using EoL membranes. The rejection of Na2SO4, MgSO4 and MgCl2 salt solutions was in the range of (50.0-85.8%) with a highest rejection value was obtained for Na2SO4 and the lowest rejection was observed for MgCl2 solution, while a complete rejection was achieved for humic acid. Salt rejection of real brackish water filtration by the EoL membranes (75-77%) presented NF-like properties (Salt rejection was obtained for NF90 membrane was 77%). Therefore, the potential of reusing EoL SWRO is promising and thus benefit the desalination industry and the environment in Oman.

Today, reverse osmosis membranes are the leading technology for new desalination installations, however, a challenge facing widespread application of RO technology is membrane fouling. In the present study, we used an environmentally friendly green inhibitor as anti-scaling and anti-biofouling in reverse osmosis (RO) desalination plants. The influence of Sargassum sp., Corallina mediterranea, and Avicennia marina on RO membrane mineral scaling was evaluated using gypsum as a model scalant. Antibacterial properties for three marine extracts from Sargassum sp., C. mediterranea, and Avicennia marina were investigated with Gram-positive bacteria (ArthrobactersulfureusYACS14, Staphylococcus aureus) and Gram-negative bacteria (VibrioanguillarumMVM425, Escherichia coli). The antimicrobial results were detected for the two selected extracts as the most potent extracts (ethyl acetate, methanol crude extracts of the Avicennia marina leaves). Data showed that ratios of 3 and 5% recorded the highest suppression percentages (100%) for all tested bacteria including bacterial community collected from Eastern Harbor. On the other side, data confirmed that the anti-scalant properties by 100 ppm of Avicennia marina leave extract giving 85% of scale inhibition. The effect of Avicennia marina leaves extract for calcium sulfate dihydrate (gypsum) scaling on selected reverse osmosis (RO) membrane surfaces was investigated. The effect of different concentrations of Avicennia marina leaves extract was observed in the extent of surface scale coverage and surface crystal size among the membrane studied.

A feasibility study of a small-scale photovoltaic-powered reverse osmosis desalination plant for potable water and salt production in Madura Island: A techno-economic evaluation

&#x0D; Seawater intake and its treatments are one of the main upstream processes of every seawater desalination plant (RO, ED, MSF, MED). However, the process has turned out to be of utmost importance for reverse osmosis (RO) desalination plant. It is to be sure that sufficient and steady flow and quality of water is available to the RO desalination plant. Prior to RO feed water, the seawater intake pre-treatment process has to be tailored and the quality of seawater intake to be treated either subsurface intake or open surface intakes, particularly when treating open surface intakes seawater (OSIS) with exceedingly unpredictable quality. According to the well-established membrane manufacturer and supplier, the RO membrane warranty and guarantee are depended on seawater intake quality and its pre-treatment. Thus, the current state-of-the-art RO membranes life and performance success for desalination processing depend upon OSIS pre-treatment processing techniques. This article is emphasizing an overview on recent OSIS and its pre-treatment techniques for RO desalination plant.&#x0D;