Estimating the cost of desalination plants using a cost database

Impact of solar energy cost on water production cost of seawater desalination plants in Egypt

Hybrid membrane system for desalination and wastewater treatment : Integrating forward osmosis and low pressure reverse osmosis

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Chronic Kidney Disease of uncertain etiology (CKDu) is a fatal disease which causes death from kidney failure due to the unknown risk factors and has already affected more than 400,000 people in rural agricultural landscape (dry zone) of Sri Lanka. This has become a major health hazard in Sri Lanka. The drinking water is supplied using bowsers and several reverse osmosis (RO) plants have been installed in some areas of Sri Lanka and they are not viable solutions. Therefore, rainwater comes up as an alternative for drinking water. The primary objective of this study is to determine whether rainwater can be used as an alternative safe drinking water source in Girandurukotte area in terms of water quality. The physical, chemical and biological analysis were performed to compare the water quality parameters of 3 water sources (groundwater, surface water and rainwater) in the Girandurukotte area. The sample size of each source is 20 (n=20) and rainwater collected in pre-monsoon and post-monsoon periods. The most common storage tanks (polyethylene (PE) and ferrocement (FC) were subjected to this study to compare the water quality depending on the material of the rainwater tank. The results show that there is a significant difference in rainwater in terms of water quality compared to groundwater and surface water. There is a significant difference (p<0.05) in parameters such as, colour, turbidity, pH, Cd, As, Zn, Pb, Na, K, Mg, free ammonia, fluoride, total hardness, total alkalinity, nitrate and nitrite. In the comparison of storage material, rainwater in FC tank was high in pH while rainwater in PE tank was lower in pH and have a significant difference (p<0.05) for some water quality parameters such as pH, total alkalinity and total dissolved solids. Still water quality of rainwater collected in both tanks (PE and FC) was within portable drinking water standards (Sri Lanka Standards; 614, 2013) and there is no likelihood of Cd, Pb and As contamination in rainwater and fluoride content, hardness is well below safe limits. Keywords: CKDu, Rainwater harvesting, Groundwater, Ferrocement, Polyethylene

Design of a 1.4 mgd desalination plant based on MSF and RO processes for an arid area in India

Design of a 1.4 mgd desalination plant based on MSF and RO processes for an arid area in India

Design of a small mobile PV-driven RO water desalination plant to be deployed at the northwest coast of Egypt

Purpose: review of existing technologies and methods of seawater desalination for drinking water supply. Discussion. Based on modern research methods using statistical data and a review of domestic and foreign literature, a review of methods and technologies for desalination and desaltation of highly mineralized natural waters was carried out. The use of sea water for domestic purposes is impossible due to the high content of minerals, however, after desalination, such water can be used for drinking. The choice of technologies and methods of desalination is primarily determined by the quality of source water, as well as the requirements for the quality of treated water, plant productivity and technical and economic calculations. For the drinking water supply purposes, the most efficient and cost-effective method is desalination using reverse osmosis technology, used for both sea and groundwater with high salinity. Reverse osmosis technology has significant advantages over thermal desalination, especially when applied to small-scale plants of small domestic water supply systems. The use of reverse osmosis plants will significantly increase productivity of drinking water output per watt of electricity consumed. Conclusions. The introduction of modern technologies and careful attention to water consumption play a significant role in maintaining water balance in different countries. The most cost-effective and efficient method is seawater desalination using reverse osmosis plants. Despite the fact that water desalination and desaltion plants are very expensive, the conservation of natural waters is a priority nowadays.

Quality of produced water is usually the criterion for selecting between different desalination technologies for turning seawater into drinking water. However, contemporary trend in drinking water treatment sees a convergence between different technologies for the same water quality. Hence, how do different desalination technologies differentiate amongst each other? Awareness of climate change impact as well as price of produced water, energy use per unit of treated water is an oft-used criterion for assessing the effectiveness and efficiency of different desalination technologies. Specifically, comparing multi-effect flash evaporation and reverse osmosis, the latter enjoys a significant energy use advantage given the lack of the need for converting water into the vapor phase as in multi-effect flash evaporation. Thus, energy used in producing drinking water is significantly higher in multi-effect flash evaporation compared to the high pressure process of reverse osmosis. From the operation perspective, reverse osmosis also benefits from its ability to scale linearly in increasing water production capacity through addition of extra membrane modules, which is not the case for multi-effect flash evaporation where a new distillation column is required for significant increase in production capacity. Collectively, with the same quality of water produced by different desalination technologies, comparison between different technologies increasingly relies on the energy use per unit of produced water. Using this criterion, reverse osmosis membrane desalination has a significant advantage relative to multi-effect flash evaporation in energy cost, which translates to a lower price of produced water.

Desalination of brackish water by nanofiltration and reverse osmosis

In the past few years, the commercialization of small scale reverse osmosis (RO) plant for low total dissolved solids (TDS) brackish and contaminated groundwater water desalination offered an alternative solution to obtain drinking water with TDS lower than 500 mg/L. Due to rapid development in membrane technology the technical and economical usefulness of RO process has been improved. In the current research work, a prototype Reverse Osmosis (RO) wastewater treatmentplant has been developed and its performance was evaluated to produce the safe and drinkable water at local small community.Salt rejection and ermeatewater flowrate are the key performance parameters. These performance parameters are influenced by other variable parameters such as applied feed pressure, temperature, recovery and feed water salinity.The RO plant performance has been evaluated through testing different water quality parameters; including physical, chemical and biological analysis of the treated sample. The plant was operated by varying feed water pressures and feed water salinity which indicated that the product water has the highest quality and maximum permeateflow rate at 25 bar of applied feed water pressure for feed water salinity upto 4000 mg/L. The water quality results indicate that permeate obtained after treatment has excellent quality free physical and microbial contaminants.

Water scarcity represents one of the most critical environmental and economic challenges worldwide, especially in arid and semi-arid regions lacking access to reliable freshwater sources. In response, seawater desalination has emerged as a strategic solution to ensure a sustainable and secure supply of potable water for various applications. Among desalination technologies, Reverse Osmosis (RO) stands out for its high efficiency and widespread adoption, primarily due to its relatively low specific energy consumption compared to thermal-based methods. However, high operational costs particularly those related to energy consumption remain a barrier, as most conventional desalination plants rely on fossil fuels, contributing significantly to greenhouse gas emissions and environmental degradation. In this context, integrating renewable energy sources, specifically solar photovoltaic (PV) and wind energy, offers a viable pathway to reduce operational expenditures and minimize environmental impact. Several studies have demonstrated that hybrid renewable energy systems can enhance the sustainability and energy autonomy of desalination plants, aligning with Global Sustainable Development Goals (SDGs). This study conducts a techno-economic analysis of a Seawater Reverse Osmosis (SWRO) plant located in Al Wajh, Saudi Arabia. Detailed Capital expenditures (CAPEX) and Operational Expenditures (OPEX) were estimated for both conventional electricity-based operation and for configurations utilizing solar and wind energy in the same location. An energy simulation model was conducted to determine the optimal number of wind turbines required to maximize energy efficiency while minimizing excess power generation. The analysis revealed that the SWRO powered by renewable energy achieved an energy efficiency of 99%, compared to its conventional electricity-powered counterpart, with an energy surplus of no more than 4%. CAPEX and OPEX cost projections were calculated for both scenarios: conventional grid electricity and renewable energy sources. The findings indicated that the unit production cost per cubic meter of the SWRO plant was 0.59–0.76 $/m3 in the case of grid electricity, whereas it was 0.74–1.12 $/m3 under renewable energy integration. This cost disparity is primarily attributed to the higher CAPEX required for the renewable energy-powered SWRO system, which amounted to 0.28–0.36 $/m3, in contrast to a significantly lower CAPEX of only 0.06–0.09 $/m3 for the electricity-based SWRO configuration. Moreover, artificial intelligence (AI) was employed to support the results and forecast future water demand based on regional climate conditions and consumption patterns. The study concludes with a set of recommendations aimed at optimizing the integration of renewable energy technologies into desalination systems to enhance long-term economic and environmental sustainability.

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&amp;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&amp;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.

Objectives The production cost of reverse osmosis (RO) seawater desalination plant is determined by the CAPEX (Capital expenditure) and OPEX (Operating expenditure). In detail, CAPEX and OPEX are composed of direct cost, overhead cost, electricity cost, and other O&M costs. However, CAPEX and OPEX may vary by country and region. Therefore, this study tries to estimate the production cost by calculating the construction and maintenance costs depending on production capacities based on the operation results such as TDS concentration and the energy consumption from a seawater desalination plant in Korea. Methods A two-stage RO based seawater desalination plant with a capacity of 10 MIGD (45,000 m3/d) was used in this study. The plant consists of a 2 MIGD (9,000 m3/d) unit having DABF (Dissolved air bio-ball filter) and UF (Ultrafiltration) as pretreatment processes, and another 8 MIGD (36,000 m3/d) unit having DABF and DMF (Dual media filtration) as pretreatment processes. To estimate the production cost, construction and maintenance costs were calculated by using GWI's Desaldata cost estimator. CAPEX (Capital expenditure) was calculated based on production capacity, recovery rate, TDS concentration and temperature of seawater, while OPEX (Operating expenditure) was calculated based on production capacity, country, energy consumption, and electricity unit price. Results and Discussion The energy consumptions from EMS (Energy Management System) were 5.48 kWh/m3 at SLC (9,000 m3/d) and 3.4 kWh/m3 at MLC (45,000 m3/d), respectively. In the CAPEX, MLC was reduced by 395,954 ￦/m3 compared to SLC, and the LLC was lower by 192,019 ￦/m3 than MLC. Overall, CAPEX decreased as the production capacity increased. The CAPEX of small plants with production capacity between 10,000 and 50,000 m3/d was significantly different; however, there was no significant difference in larger plants having a capacity above 100,000 m3/d. The OPEX for the annual production capacity showed a sizable difference with 742.3 ￦/m3, 636.5 ￦/m3 and 580.3 ￦/m3 for SLC, MLC, and LLC, respectively. The electricity cost was a substantial portion of OPEX. Also, the production costs based on the interest rates (3% and 5%) were 1,326-1,384 ￦/m3, 1,163-1,209 ￦/m3, and 1,023-1,070 ￦/m3 for SLC, MLC, and LLC, respectively. The results were consistent with 1.0 US$/m3, which is the average production costs presented from other references. Conclusions The production cost estimated using the Desaldata cost estimator based on the CAPEX and OPEX tends to decrease as the capacity increases. However, when the capacity increased over 50,000 m3/d, the production cost decreased by an average of 40 ￦/m3. Thus the decrement of production cost reduced. From these results, the production cost of tap water through seawater desalination was estimated between 1,023 ￦/m3 and 1,070 ￦/m3 above 100,000 m3/d. Therefore, it is difficult to introduce a large-scale desalination plant in Korea, because the average tap water price was 834.6 ￦ in Korea in 2017. However, It is expected that the seawater desalination will be introduced as an alternative water source whenever drinking water price rises, or when the quantity of available drinking water sources reduce due to climate change and water pollution, or whenever energy consumption is reduced as a result of the steady development of the component technologies such as the reverse osmosis membrane, high-pressure pump, and energy recovery device. Key words: Reverse osmosis seawater desalination plant, Water price, Capital expenditure, Operating expenditure, Energy consumption