Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems
Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems

Author: Nirajan Dhakal

Publisher: CRC Press

Published: 2017-12-01

Total Pages: 175

ISBN-13: 1351056085

DOWNLOAD EBOOK

Seawater desalination is a rapidly growing coastal industry that is increasingly threatened by algal blooms. Depending on the severity of algal blooms, desalination systems may be forced to shut down because of clogging and/or poor feed water quality. To maintain stable operation and provide good feed water quality to seawater reverse osmosis (SWRO) systems, ultrafiltration (UF) pre-treatment is proposed. This research focused on assessing the ability of UF and other pre-treatment technologies to reduce biofouling in SWRO systems. An improved method to measure bacterial regrowth potential (BRP) was developed and applied at laboratory, pilot and full scale to assess the ability of conventional UF (150 kDa) and tight UF (10 kDa) alone and in combination with a phosphate adsorbent to reduce regrowth potential and delay the onset of biofouling in SWRO. The improved bacterial regrowth potential method employs a natural consortium of marine bacteria as inoculum and flow cytometry. The limit of detection of the BRP method was lowered to 43,000 ± 12,000 cells/mL, which is equivalent to 9.3 ± 2.6 μg-Cglucose/L. The reduction in bacterial regrowth potential after tight UF (10 kDa) was 3 to 4 times higher than with conventional UF (150 kDa). It was further reduced after the application of a phosphate adsorbent, independent of pore size of the UF membrane. Pilot studies demonstrated that the application of tight UF (10 kDa) coupled with a phosphate adsorbent consistently lowered the bacterial regrowth potential and no feed channel pressure drop increase was observed in membrane fouling simulators (MFS) over a period of 21 days. The study also showed that non-backwashable fouling of UF membranes varied strongly with the type of algal species and the algal organic matter (AOM) they release. The presence of polysaccharide (stretching -OH) and sugar ester groups (stretching S=O) was the main cause of non-backwashable fouling. In conclusion, this study showed that an improved BRP method is suitable for the assessment of SWRO pre-treatment systems and it can be a useful tool to develop potential strategies to mitigate biofouling and improve the sustainability of SWRO systems.

Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems
Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems

Author: Nirajan Dhakal

Publisher: CRC Press

Published: 2017-12-01

Total Pages: 208

ISBN-13: 1351056093

DOWNLOAD EBOOK

Seawater desalination is a rapidly growing coastal industry that is increasingly threatened by algal blooms. Depending on the severity of algal blooms, desalination systems may be forced to shut down because of clogging and/or poor feed water quality. To maintain stable operation and provide good feed water quality to seawater reverse osmosis (SWRO) systems, ultrafiltration (UF) pre-treatment is proposed. This research focused on assessing the ability of UF and other pre-treatment technologies to reduce biofouling in SWRO systems. An improved method to measure bacterial regrowth potential (BRP) was developed and applied at laboratory, pilot and full scale to assess the ability of conventional UF (150 kDa) and tight UF (10 kDa) alone and in combination with a phosphate adsorbent to reduce regrowth potential and delay the onset of biofouling in SWRO. The improved bacterial regrowth potential method employs a natural consortium of marine bacteria as inoculum and flow cytometry. The limit of detection of the BRP method was lowered to 43,000 ± 12,000 cells/mL, which is equivalent to 9.3 ± 2.6 μg-Cglucose/L. The reduction in bacterial regrowth potential after tight UF (10 kDa) was 3 to 4 times higher than with conventional UF (150 kDa). It was further reduced after the application of a phosphate adsorbent, independent of pore size of the UF membrane. Pilot studies demonstrated that the application of tight UF (10 kDa) coupled with a phosphate adsorbent consistently lowered the bacterial regrowth potential and no feed channel pressure drop increase was observed in membrane fouling simulators (MFS) over a period of 21 days. The study also showed that non-backwashable fouling of UF membranes varied strongly with the type of algal species and the algal organic matter (AOM) they release. The presence of polysaccharide (stretching -OH) and sugar ester groups (stretching S=O) was the main cause of non-backwashable fouling. In conclusion, this study showed that an improved BRP method is suitable for the assessment of SWRO pre-treatment systems and it can be a useful tool to develop potential strategies to mitigate biofouling and improve the sustainability of SWRO systems.

Biofouling of Spiral Wound Membrane Systems
Biofouling of Spiral Wound Membrane Systems

Author: Johannes Simon Vrouwenvelder

Publisher: IWA Publishing

Published: 2011-03-15

Total Pages: 355

ISBN-13: 1843393638

DOWNLOAD EBOOK

The study of membrane biofouling has increased strongly in the past four years, compared to the previous twenty two years, indicated by the more than doubling of the number of scientific papers. However, no single source gives an updated overview of biofouling. Biofouling of Spiral Wound Membrane Systems gives a complete and comprehensive overview of all aspects of biofouling, bridging the gap between microbiology, hydraulics and membrane technology. High quality drinking water can be produced with membrane filtration processes like reverse osmosis (RO) and nanofiltration (NF). As the global demand for fresh clean water is increasing, these membrane technologies are increasingly important. One of the most serious problems in RO/NF applications is biofouling – excessive growth of biomass – affecting the performance of the RO/NF systems. This can be due to the increase in pressure drop across membrane elements (feed-concentrate channel), the decrease in membrane permeability or the increase in salt passage. These phenomena result in the need to increase the feed pressure to maintain constant production and to clean the membrane elements chemically. Biofouling of Spiral Wound Membrane Systems relates biomass accumulation in spiral wound RO and NF membrane elements with membrane performance and hydrodynamics and determines parameters influencing biofouling. It focuses on the development of biomass in the feed-concentrate (feed-spacer) channel and its effect on pressure drop and flow distribution. It can be used to develop an integral strategy to control biofouling in spiral wound membrane systems. Most past and present methods to control biofouling have not been very successful. An overview of several potential complementary approaches to solve biofouling is given and an integrated approach for biofouling control is proposed.

Intakes and Outfalls for Seawater Reverse-Osmosis Desalination Facilities
Intakes and Outfalls for Seawater Reverse-Osmosis Desalination Facilities

Author: Thomas M. Missimer

Publisher: Springer

Published: 2015-04-07

Total Pages: 551

ISBN-13: 3319132032

DOWNLOAD EBOOK

The book assembles the latest research on new design techniques in water supplies using desalinated seawater. The authors examine the diverse issues related to the intakes and outfalls of these facilities. They clarify how and why these key components of the facilities impact the cost of operation and subsequently the cost of water supplied to the consumers. The book consists of contributed articles from a number of experts in the field who presented their findings at the "Desalination Intakes and Outfalls" workshop held at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia in October, 2013. The book integrates coverage relevant to a wide variety of researchers and professionals in the general fields of environmental engineering and sustainable development.

Membranes for Water Treatment
Membranes for Water Treatment

Author: Klaus-Viktor Peinemann

Publisher: John Wiley & Sons

Published: 2010-11-29

Total Pages: 251

ISBN-13: 9783527631414

DOWNLOAD EBOOK

This ready reference on Membrane Technologies for Water Treatment, is an invaluable source detailing sustainable, emerging processes, to provide clean, energy saving and cost effective alternatives to conventional processes. The editors are internationally renowned leaders in the field, who have put together a first-class team of authors from academia and industry to present a highly approach to the subject. The book is an instrumental tool for Process Engineers, Chemical Engineers, Process Control Technicians, Water Chemists, Environmental Chemists, Materials Scientists and Patent Lawyers.

Assessing Bacterial Growth Potential in Seawater Reverse Osmosis Pretreatment
Assessing Bacterial Growth Potential in Seawater Reverse Osmosis Pretreatment

Author: Almotasembellah Abushaban

Publisher: CRC Press

Published: 2020-01-21

Total Pages: 146

ISBN-13: 1000034704

DOWNLOAD EBOOK

Seawater desalination is increasingly being used as a means to augment freshwater supplies in regions with high water stress, and reverse osmosis is increasingly the technology of choice because of the low energy consumption. However, seawater reverse osmosis (SWRO) systems suffer from various types of fouling, which can increase energy consumption and the use of chemicals during SWRO operation. In practice, pre-treatment systems are put in place to reduce the particulate and biological fouling potential of SWRO feed water. However, simple, reliable and accurate methods to assess the extent to which biological fouling potential is reduced during pre-treatment are not available for seawater. This research developed a new method to measure bacterial growth potential (BGP) using the native bacterial consortium in seawater. New reagents to extract and detect ATP in microbial cells were specifically developed for seawater. The new lysis and detection reagents overcame the salt interference in seawater and allow low detection of total ATP, free ATP and microbial ATP in seawater. Incorporating a filtration step further increased the sensitivity of the method six fold, enabling ATP detection of ultra-low levels of microbial ATP in seawater. The newly developed ATP-based BGP method was applied to monitor and assess the pre-treatment of five full-scale seawater desalination plants around the world. A good correlation was observed between BGP measured in SWRO feed water and the pressure drop increase in the SWRO systems, suggesting the applicability of using the ATP-based BGP method as a biofouling indicator in SWRO. Furthermore, a safe level of BGP ( In the future, on-line monitoring of BGP in SWRO feed water may further reduce the consumption of chemicals and energy and improve the overall sustainability of seawater desalination by reverse osmosis.

Osmotically Driven Membrane Processes
Osmotically Driven Membrane Processes

Author: Hongbo Du

Publisher: BoD – Books on Demand

Published: 2018-03-28

Total Pages: 283

ISBN-13: 9535139215

DOWNLOAD EBOOK

Osmotically driven membrane processes (ODMPs) including forward osmosis (FO) and pressure-retarded osmosis (PRO) have attracted increasing attention in fields such as water treatment, desalination, power generation, and life science. In contrast to pressure-driven membrane processes, e.g., reverse osmosis, which typically employs applied high pressure as driving force, ODMPs take advantages of naturally generated osmotic pressure as the sole source of driving force. In light of this, ODMPs possess many advantages over pressure-driven membrane processes. The advantages include low energy consumption, ease of equipment maintenance, low capital investment, high salt rejection, and high water flux. In the past decade, over 300 academic papers on ODMPs have been published in a variety of application fields. The number of such publications is still rapidly growing. The ODMPs' approach, fabrications, recent development and applications in wastewater treatment, power generation, seawater desalination, and gas absorption are presented in this book.

Osmotically Driven Membrane Processes
Osmotically Driven Membrane Processes

Author: Muharrem Ince

Publisher: BoD – Books on Demand

Published: 2022-02-16

Total Pages: 136

ISBN-13: 1839689110

DOWNLOAD EBOOK

Osmotically Driven Membrane Processes provides an overview of membrane systems and separation processes, recent trends in membranes and membrane processes, and advancements in osmotically driven membrane systems. It focuses on recent advances in monitoring and controlling wastewater using membrane technologies. It explains and clarifies important research studies as well as discusses advancements in the field of organic-inorganic pollution.