Phosphate removal in seawater reverse osmosis feed water: An option to control biofouling

Purpose This paper aims to determine the optimum arrangement of a reverse osmosis system in two methods of plug and concentrate recycling. Design/methodology/approach To compare the optimum conditions of these two methods, a seawater reverse osmosis system was considered to produce fresh water at a rate of 4,000 m3/d for Mahyarkala city, located in north of Iran, for a period of 20 years. Using genetic algorithms and two-objective optimization method, the reverse osmosis system was designed. Findings The results showed that exergy efficiency in optimum condition for concentrate recycling and plug methods was 82.6 and 92.4 per cent, respectively. The optimizations results showed that concentrate recycling method, despite a 36 per cent reduction in the initial cost and a 2 per cent increase in maintenance expenses, provides 6 per cent higher recovery and 19.7 per cent less permeate concentration than two-stage plug method. Originality/value Optimization parameters include feed water pressure, the rate of water return from the brine for concentrate recycling system, type of SW membrane, feedwater flow rate and numbers of elements in each pressure vessel (PV). These parameters were also compared to each other in terms of recovery (R) and freshwater unit production cost. In addition, the exergy of all elements was analyzed by selecting the optimal mode of each system.

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Enhancing boron rejection in seawater reverse osmosis facilities

Water Science & Technology Water Supply ◽

10.2166/ws.2008.117 ◽

2008 ◽

Vol 8 (5) ◽

pp. 519-525 ◽

Cited By ~ 2

Author(s):

R. P. Huehmer ◽

F. Wang ◽

J. Lozier ◽

L. Henthorne

Keyword(s):

Reverse Osmosis ◽

World Health ◽

Feed Water ◽

Natural Seawater ◽

Potential Health ◽

Pass System ◽

Wide Range ◽

Seawater Reverse Osmosis ◽

Health Organization ◽

High Rejection

Linked to potential health problems and toxicity to crops, boron is present in seawater at concentrations of ranging from 4 to 7 mg/L, and not readily removed by reverse osmosis technology. Commercially available seawater reverse osmosis (SWRO) membranes possess a wide range of rejection characteristics for boron in seawater under ambient temperature and pH, ranging from approximately 50% for low-energy membranes to greater than 90% for the newest high rejection membranes. This level of rejection is typically insufficient to reduce boron concentrations in natural seawater to less than recommended levels. Current World Health Organization (WHO) drinking water concentrations for boron are limited to 0.5-mg/L. Two techniques utilized to mitigate boron concentrations are (1) increasing the dissociation of boric acid by increasing pH prior to SWRO; and, (2) utilizing a second pass reverse osmosis system, potentially coupled with pH adjustment. Utilizing these techniques, the authors tested commercially available SWRO membranes from three different manufacturers utilizing feed water alkalization, coupled with a second pass system. Utilizing feed water alkalization alone, the authors found that all three SWRO membranes were able to produce permeate complying with WHO regulations. Using second pass RO, a boron concentration of less than 0.5 mg/L was achieved for feed pH greater than 6, and less than 0.1-mg/L for pH of 10.

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Kristal® 2000 PVDF hollow fiber UF membrane in the pretreatment for seawater desalination

Water Practice & Technology ◽

10.2166/wpt.2012.058 ◽

2012 ◽

Vol 7 (4) ◽

Cited By ~ 2

Author(s):

Zanguo Peng ◽

Zhaoxuan Zhang ◽

Pandurangan Mohan ◽

Kasinathan Manimaran ◽

Dongfei Li

Keyword(s):

Water Quality ◽

Pilot Study ◽

Reverse Osmosis ◽

Hollow Fiber ◽

Large Scale ◽

Operating Costs ◽

Feed Water ◽

Seawater Desalination ◽

Seawater Reverse Osmosis ◽

Uf Membranes

Membrane technology has emerged as a dominant solution to seawater desalination due to its superior advantages such as stable output water quality, lower energy consumption, ease of operation and smaller footprint. However, the design of spiral wound reverse osmosis (RO) membranes used in desalination does not allow for backwash or air scouring, thus rendering the RO membrane highly susceptible to fouling. Pretreatment for the RO system is therefore essential to ensure a long service life of the RO membranes. For waters containing suspended solids of up to 75 mg/L (such as that in the SingSpring Desalination Plant at Tuas, Singapore), conventional pretreatment methods (such as dissolved air floatation and filtration (DAFF), chemical dosing and cartridge filtration) require regular operator intervention to produce a permeate of reasonably quality. Ultrafiltration (UF) as a pretreatment for seawater desalination can offer better treated water, lower operating costs, a smaller footprint, and flexibility in dealing with poor or varying feed water quality. By improving the pretreatment permeate water quality, reducing operating costs and the footprint, capital expenses can be lowered. Greater stability is also achieved during times of poor or variable feed water conditions (such as periods of algalbloom). A pilot study was conducted at SingSpring to track the performance of Hyflux's Kristal® 2000 hollow fiber UF membranes as pretreatment for the seawater reverse osmosis (SWRO) system. The results of the pilot study will enable the design of future large-scale UF-SWRO membrane projects for seawater desalination.

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Characterization of seawater reverse osmosis fouled membranes from large scale commercial desalination plant

10.31221/osf.io/96zj5 ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Reverse Osmosis ◽

Large Scale ◽

Retention Rate ◽

Local Level ◽

Microscopic Analysis ◽

Transmembrane Pressure ◽

Hydraulic Permeability ◽

Seawater Reverse Osmosis ◽

A Chain

The objective of this work is to study the ageing state of a used reverse osmosis (RO) membrane taken in Algeria from the Benisaf Water Company seawater desalination unit. The study consists of an autopsy procedure used to perform a chain of analyses on a membrane sheet. Wear of the membrane is characterized by a degradation of its performance due to a significant increase in hydraulic permeability (25%) and pressure drop as well as a decrease in salt retention (10% to 30%). In most cases the effects of ageing are little or poorly known at the local level and global measurements such as (flux, transmembrane pressure, permeate flow, retention rate, etc.) do not allow characterization. Therefore, a used RO (reverse osmosis) membrane was selected at the site to perform the membrane autopsy tests. These tests make it possible to analyze and identify the cause as well as to understand the links between performance degradation observed at the macroscopic scale and at the scale at which ageing takes place. External and internal visual observations allow seeing the state of degradation. Microscopic analysis of the used membranes surface shows the importance of fouling. In addition, quantification and identification analyses determine a high fouling rate in the used membrane whose foulants is of inorganic and organic nature. Moreover, the analyses proved the presence of a biofilm composed of protein.

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Numerical methodology and CFD simulations of a rotary vane energy recovery device for seawater reverse osmosis desalination systems

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2021.116788 ◽

2021 ◽

Vol 190 ◽

pp. 116788

Author(s):

Fanghua Ye ◽

Giuseppe Bianchi ◽

Sham Rane ◽

Savvas A. Tassou ◽

Jianqiang Deng

Keyword(s):

Reverse Osmosis ◽

Energy Recovery ◽

Cfd Simulations ◽

Seawater Reverse Osmosis ◽

Reverse Osmosis Desalination

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Full-Scale Seawater Reverse Osmosis Desalination Plant Simulator

IFAC-PapersOnLine ◽

10.1016/j.ifacol.2020.12.780 ◽

2020 ◽

Vol 53 (2) ◽

pp. 16561-16568

Author(s):

Mariam Elnour ◽

Nader Meskin ◽

Khlaed M. Khan ◽

Raj Jain ◽

Syed Zaidi ◽

...

Keyword(s):

Reverse Osmosis ◽

Full Scale ◽

Desalination Plant ◽

Seawater Reverse Osmosis ◽

Reverse Osmosis Desalination

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Seawater reverse osmosis at high pressures

Desalination ◽

10.1016/0011-9164(85)80003-5 ◽

1985 ◽

Vol 54 ◽

pp. 19-26 ◽

Cited By ~ 3

Author(s):

C.T. Sackinger

Keyword(s):

Reverse Osmosis ◽

High Pressures ◽

Seawater Reverse Osmosis

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Novel pre-treatment method for seawater reverse osmosis: Fibre media filtration

Desalination ◽

10.1016/j.desal.2009.09.023 ◽

2010 ◽

Vol 250 (2) ◽

pp. 557-561 ◽

Cited By ~ 17

Author(s):

J.J. Lee ◽

M.A.H. Johir ◽

K.H. Chinu ◽

H.K. Shon ◽

S. Vigneswaran ◽

...

Keyword(s):

Reverse Osmosis ◽

Treatment Method ◽

Seawater Reverse Osmosis ◽

Pre Treatment

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Environmental Performance of Small-Scale Seawater Reverse Osmosis Plant for Rural Area Water Supply

Membranes ◽

10.3390/membranes11010040 ◽

2021 ◽

Vol 11 (1) ◽

pp. 40

Author(s):

Latifah Abdul Ghani ◽

Nora’aini Ali ◽

Ilyanni Syazira Nazaran ◽

Marlia M. Hanafiah

Keyword(s):

Drinking Water ◽

Global Warming ◽

Water Supply ◽

Reverse Osmosis ◽

Resource Scarcity ◽

Small Scale ◽

Seawater Desalination ◽

Seawater Reverse Osmosis ◽

Desalination Technology ◽

The Impact

Seawater desalination is an alternative technology to provide safe drinking water and to solve water issues in an area having low water quality and limited drinking water supply. Currently, reverse osmosis (RO) is commonly used in the desalination technology and experiencing significant growth. The aim of this study was to analyze the environmental impacts of the seawater reverse osmosis (SWRO) plant installed in Kampung Pantai Senok, Kelantan, as this plant was the first installed in Malaysia. The software SimaPro 8.5 together with the ReCiPe 2016 database were used as tools to evaluate the life cycle assessment (LCA) of the SWRO plant. The results showed that the impact of global warming (3.90 kg CO2 eq/year) was the highest, followed by terrestrial ecotoxicity (1.62 kg 1,4-DCB/year) and fossil resource scarcity (1.29 kg oil eq/year). The impact of global warming was caused by the natural gas used to generate the electricity, mainly during the RO process. Reducing the environmental impact can be effectively achieved by decreasing the electricity usage for the seawater desalination process. As a suggestion, electricity generation can be overcome by using a high-flux membrane with other suitable renewable energy for the plant such as solar and wind energy.

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