First year performance review of Magong UF/RO Seawater Desalination Plant

Ion-exchange membrane electrodialytic salt production using brine discharged from a reverse osmosis seawater desalination plant

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

Preliminary experimental analysis of a small-scale prototype SWRO desalination plant, designed for continuous adjustment of its energy consumption to the widely varying power generated by a stand-alone wind turbine

Inorganic scaling is a major concern for thermal and reverse osmosis (RO) seawater desalination plants, which are the key technologies for meeting the increasing freshwater demand. Membrane scaling is a detrimental effect in both thermal and RO process that reduces its performance particularly by reducing the water flux and causing membrane wetting. In this chapter, the formation mechanisms of inorganic scaling in thermal and reverse osmosis plants are discussed. The factors contributing to scale formation such as temperature, pH, and ionic strength of the treated water and the scale indices frequently used to predict the scale formation are explained. Finally, prevention methodologies developed to mitigate inorganic scaling (pre-treatment strategies, cleaning processes, advanced materials, etc.) are enumerated and discussed. Overall, this chapter provides a fundamental perspective of the inorganic scaling in thermal and reverse osmosis seawater desalination plants.

Development of the most adequate pre-treatment for high capacity seawater desalination plants with open intake

Comparison of MF/UF pretreatment with conventional filtration prior to RO membranes for surface seawater desalination

ANN based-model for estimating the boron permeability coefficient as boric acid in SWRO desalination plants using ensemble-based machine learning

Optimization for design of large RO seawater desalination plants

Performance of an integrated membrane pilot plant for wastewater reuse: case study of oil refinery plant in Indonesia

Seawater reverse osmosis desalination plant at community-scale: Role of an innovative pretreatment on process performances and intensification

Fouling control in SWRO desalination during harmful algal blooms: A historical review and future developments

The increased interest in ultrafiltration technology in the last decade is caused by the search for new purification methods that allow obtaining high-quality drinking water that meets modern regulatory requirements. Modern water purification schemes use an ultrafiltration unit before reverse osmosis in softening, desalination and demineralization of water for food production. The pore size of ultrafiltration membranes ranges from 5 nm to 0.05-0.1 microns. Using ultrafiltration instead of the traditional water treatment scheme, makes it possible to obtain water with a low content of suspended and colloidal substances, increase the productivity and serviceability of reverse osmosis membranes. The water treatment scheme may contain the following modules: coarse filter; ultrafiltration unit, buffer tank; mixer; water container; reverse osmosis installation; pumps. The method of differential scanning microscopy is used to assess the quality of water during its purification. Water samples were cooled with liquid nitrogen to -30 ? and then heated to 30 ?. Crystals melting peaks were recorded on the DSC curves, and the thermal effect was calculated. During the water purification process, the value of the thermal effect of frozen water samples melting declines (from 515.1 to 261.2 J / g), the value of the temperatures at the onset (from 0.7 to -0.13 ?) and at the peak of crystal melting (from 7.45 up to 4.27 ?). The difference between the heat effect data for water samples after coarse filtration and ultrafiltration is small, which indicates that the ultrafiltration unit allows cations and anions to pass through, which preserves the salt balance of water.

Seawater desalination by reverse osmosis : Plant design, performance data, operation and maintenance (Tanajib, Arabian Gulf Coast)

A large-scale parallel-unit seawater reverse osmosis desalination plant contains many reverse osmosis (RO) units. If the operating conditions change, these RO units will not work at the optimal design points which are computed before the plant is built. The operational optimization problem (OOP) of the plant is to find out a scheduling of operation to minimize the total running cost when the change happens. In this paper, the OOP is modelled as a mixed-integer nonlinear programming problem. A two-stage differential evolution algorithm is proposed to solve this OOP. Experimental results show that the proposed method is satisfactory in solution quality.

The ability to produce fresh potable water is an ever-growing challenge, especially with an increase in drought conditions worldwide. Due to its capacity to treat different types of water, reverse osmosis (RO) technology is an increasingly popular solution to the water shortage problem. The major restriction associated with the treatment of water by RO technology is the fouling of the RO membrane, in particular through biofouling. Membrane fouling is a multifaceted problem that causes an increase in operating pressure, frequent cleaning and limited membrane lifespan. The current paper summarizes the impact of biofouling of RO membranes used in seawater desalination plants. Following a brief introduction, the elements that contribute to biofouling are discussed: biofilm formation, role of extracellular polymeric substances (EPS), marine environment, developmental phases of biofouling. Following this, is a section on the implications of membrane biofouling especially permeate flux and salt rejection. The final section focuses on the new phenomenon of compression and hydraulic resistance of biofilms. Lastly, considerations on future research requirements on biofouling and its control in seawater reverse osmosis (SWRO) membrane systems are presented at the end of the article.