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Chemical Cleaning Of Ultrafiltration Membrane After Treatment Of Oily Wastewater

Abstract: Oily wastewaters and Oil–in-water emulsions are two of the major pollutants of the environment. Ultrafiltration (UF) membranes play an important role in the treatment and reuse of oily wastewaters. Fouling of UF membranes is typically caused by inorganic and organic materials present in wastewaters that adhere to the surface and pores of the membrane and result in the deterioration of performance with a consequent increase in energy costs and membrane replacement. In the experiments, polyacrylonitrile (PAN) and outlet wastewater of the API (American Petroleum Institute) separator unit of Tehran refinery as membrane and feed were used, respectively. Fouling and cleaning experiments were performed with oily wastewater and selected cleaning agents using a laboratory scale cross flow test unit. The results showed that metal chelating agent (ethylene diamine tetra acetic acid disodium salt-2-hydrate (EDTA)) and an anionic surfactant (sodium dodecyl sulfate (SDS)) were able to Clean the fouled UF membrane effectively by optimizing chemical (pH) and physical (cleaning time, cross flow velocity (CFV) and temperature) conditions during cleaning. Flux recovery and resistance removal were found to improve with increasing CFV, temperature, pH, cleaning time and concentration of the cleaning chemicals. In this paper, the cleaning mechanism is also investigated.
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Chemical Cleaning Of Ultrafiltration Membrane After Treatment Of Oily Wastewater

Abstract: Oily wastewaters and Oil–in-water emulsions are two of the major pollutants of the environment. Ultrafiltration (UF) membranes play an important role in the treatment and reuse of oily wastewaters. Fouling of UF membranes is typically caused by inorganic and organic materials present in wastewaters that adhere to the surface and pores of the membrane and result in the deterioration of performance with a consequent increase in energy costs and membrane replacement. In the experiments, polyacrylonitrile (PAN) and outlet wastewater of the API (American Petroleum Institute) separator unit of Tehran refinery as membrane and feed were used, respectively. Fouling and cleaning experiments were performed with oily wastewater and selected cleaning agents using a laboratory scale cross flow test unit. The results showed that metal chelating agent (ethylene diamine tetra acetic acid disodium salt-2-hydrate (EDTA)) and an anionic surfactant (sodium dodecyl sulfate (SDS)) were able to Clean the fouled UF membrane effectively by optimizing chemical (pH) and physical (cleaning time, cross flow velocity (CFV) and temperature) conditions during cleaning. Flux recovery and resistance removal were found to improve with increasing CFV, temperature, pH, cleaning time and concentration of the cleaning chemicals. In this paper, the cleaning mechanism is also investigated.
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Chemical Cleaning Effects On Properties And Separation Efciency Of An RO Membrane

Abstract: This study aims to investigate the impacts of chemical cleaning on the performance of a reverse osmosis membrane. Chemicals used for simulating membrane cleaning include a surfactant (sodium dodecyl sulfate, SDS), a chelating agent (ethylenediaminetetraacetic acid, EDTA), and two proprietary cleaning formulations namely MC3 and MC11. The impact of sequential exposure to multiple membrane cleaning solutions was also examined. Water permeability and the rejection of boron and sodium were investigated under various water fluxes, temperatures and feedwater pH. Changes in the membrane performance were systematically explained based on the changes in the charge density, hydrophobicity and chemical structure of the membrane surface. The experimental results show that membrane cleaning can significantly alter the hydrophobicity and water permeability of the membrane; however, its impacts on the rejections of boron and sodium are marginal. Although the presence of surfactant or chelating agent may cause decreases in the rejection, solution pH is the key factor responsible for the loss of membrane separation and changes in the surface properties. The impact of solution pH on the water permeability can be reversed by applying a subsequent cleaning with the opposite pH condition. Nevertheless, the impacts of solution pH on boron and sodium rejections are irreversible in most cases
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Chemical Cleaning Effects On Properties And Separation Efciency Of An RO Membrane

Abstract: This study aims to investigate the impacts of chemical cleaning on the performance of a reverse osmosis membrane. Chemicals used for simulating membrane cleaning include a surfactant (sodium dodecyl sulfate, SDS), a chelating agent (ethylenediaminetetraacetic acid, EDTA), and two proprietary cleaning formulations namely MC3 and MC11. The impact of sequential exposure to multiple membrane cleaning solutions was also examined. Water permeability and the rejection of boron and sodium were investigated under various water fluxes, temperatures and feedwater pH. Changes in the membrane performance were systematically explained based on the changes in the charge density, hydrophobicity and chemical structure of the membrane surface. The experimental results show that membrane cleaning can significantly alter the hydrophobicity and water permeability of the membrane; however, its impacts on the rejections of boron and sodium are marginal. Although the presence of surfactant or chelating agent may cause decreases in the rejection, solution pH is the key factor responsible for the loss of membrane separation and changes in the surface properties. The impact of solution pH on the water permeability can be reversed by applying a subsequent cleaning with the opposite pH condition. Nevertheless, the impacts of solution pH on boron and sodium rejections are irreversible in most cases

California Desalination Planning Handbook

Introduction: Desalination is receiving increased attention as a means for addressing the water supply challenges of California. Growing population, much of which is located in semi-arid regions of the state, and various other water demands pose increased pressure on existing water supplies. Much of California’s water supply depends on snow accumulation in the winter, providing spring runoff that flls reservoirs and replenishes often depleted groundwater supplies. But in periods of drought, water supply shortages can be encountered throughout the state, particularly in the central valley and southern portion of the state. All indications suggest the impacts of global warming will include a change in the timing of runoff and less snowfall. This will put more pressure on existing supplies, and exacerbate the impacts of drought. As the implications of global warming become clearer, more emphasis will likely be given to developing new sources of water supply to meet existing and projected demand. While conservation and recycling are recommended as the frst course of action, other alternatives (such as desalination and increased surface and groundwater storage) are receiving increased attention.
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California Desalination Planning Handbook

Introduction: Desalination is receiving increased attention as a means for addressing the water supply challenges of California. Growing population, much of which is located in semi-arid regions of the state, and various other water demands pose increased pressure on existing water supplies. Much of California’s water supply depends on snow accumulation in the winter, providing spring runoff that flls reservoirs and replenishes often depleted groundwater supplies. But in periods of drought, water supply shortages can be encountered throughout the state, particularly in the central valley and southern portion of the state. All indications suggest the impacts of global warming will include a change in the timing of runoff and less snowfall. This will put more pressure on existing supplies, and exacerbate the impacts of drought. As the implications of global warming become clearer, more emphasis will likely be given to developing new sources of water supply to meet existing and projected demand. While conservation and recycling are recommended as the frst course of action, other alternatives (such as desalination and increased surface and groundwater storage) are receiving increased attention.

Basics of Reverse Osmosis

What is Reverse Osmosis? Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi permeable membrane. This paper is aimed towards an audience that has little of no experience with Reverse Osmosis and will attempt to explain the basics in simple terms that should leave the reader with a better overall understanding of Reverse Osmosis technology and its applications.
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Basics of Reverse Osmosis

What is Reverse Osmosis? Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi permeable membrane. This paper is aimed towards an audience that has little of no experience with Reverse Osmosis and will attempt to explain the basics in simple terms that should leave the reader with a better overall understanding of Reverse Osmosis technology and its applications.

Assessment Of Best Available Technologies For Desalination In Rural/Local Areas

Introduction: The Sustainable Water Integrated Management (SWIM) is a European Union(EU)-funded Regional Technical Assistance Program [1] that “aims at supporting water governance and mainstreaming by promoting sustainable and equitable water resources management to become a prominent feature of national development policies and strategies (agriculture, industry, tourism, etc).” [2] Countries in the south of the Mediterranean are facing increasing water scarcity. This scarcity is driving the need for augmenting conventional water supply with alternative water sources. Rural and remote areas are particularly disadvantaged because such areas are often located far away from municipal water supply systems and conventional water sources, and are often not connected to the electric power grid. There is good potential for addressing the water scarcity problem in rural and remote areas through sustainable saline water desalination technologies. Seawater and brackish water desalination are well-established industries comprising a wide variety of available technologies with decades of accumulated experience. There are many advancements and evolution in desalination technologies. The numerous technologies and processes available have different characteristics, advantages and disadvantages that make each suitable for particular market segments or specific niches. Moreover, much of the cumulative technology experience is related to large urban supply plants that are either connected to the grid, or are themselves part of large power and desalination cogeneration plants. Rural and remote areas have special requirements that influence the appropriate selection of technologies. These include technical requirements related to small-scale application using renewable energy sources, ease of operation and maintenance, and simple design; requirements dictated by geographical location; as well as socio-economic and socio-cultural requirements related to the communities that are intended to operate and benefit from the technology. Successful implementation and long term sustainability (operational and environmental sustainability) of desalination projects for rural and remote locations requires that all the relevant requirements be identified and addressed from the earliest stages of the project.
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Assessment Of Best Available Technologies For Desalination In Rural/Local Areas

Introduction: The Sustainable Water Integrated Management (SWIM) is a European Union(EU)-funded Regional Technical Assistance Program [1] that “aims at supporting water governance and mainstreaming by promoting sustainable and equitable water resources management to become a prominent feature of national development policies and strategies (agriculture, industry, tourism, etc).” [2] Countries in the south of the Mediterranean are facing increasing water scarcity. This scarcity is driving the need for augmenting conventional water supply with alternative water sources. Rural and remote areas are particularly disadvantaged because such areas are often located far away from municipal water supply systems and conventional water sources, and are often not connected to the electric power grid. There is good potential for addressing the water scarcity problem in rural and remote areas through sustainable saline water desalination technologies. Seawater and brackish water desalination are well-established industries comprising a wide variety of available technologies with decades of accumulated experience. There are many advancements and evolution in desalination technologies. The numerous technologies and processes available have different characteristics, advantages and disadvantages that make each suitable for particular market segments or specific niches. Moreover, much of the cumulative technology experience is related to large urban supply plants that are either connected to the grid, or are themselves part of large power and desalination cogeneration plants. Rural and remote areas have special requirements that influence the appropriate selection of technologies. These include technical requirements related to small-scale application using renewable energy sources, ease of operation and maintenance, and simple design; requirements dictated by geographical location; as well as socio-economic and socio-cultural requirements related to the communities that are intended to operate and benefit from the technology. Successful implementation and long term sustainability (operational and environmental sustainability) of desalination projects for rural and remote locations requires that all the relevant requirements be identified and addressed from the earliest stages of the project.

An Introduction To Membrane Techniques For Water Desalination

This course is adapted from the Unified Facilities Criteria of the United States government, which is in the public domain, is authorized for unlimited distribution, and is not copyrighted.
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An Introduction To Membrane Techniques For Water Desalination

This course is adapted from the Unified Facilities Criteria of the United States government, which is in the public domain, is authorized for unlimited distribution, and is not copyrighted.
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