National Research Center, Egypt
Question
Asked 24th Mar, 2016
What are the main difficulties for RO membrane used in desalination of sea/ocean water?
from operational and maintenance point view and their reflect on the plant recovery and lifetime.
Most recent answer
Prof Dr Gamal Khedr
Dear Mr Abdullah Albiladi
Our published research works showed that the main membrane problem in RO and NF applications, in the hot countries of the Middle East and the Arabian Gulf , is bio/organic fouling .It is found to be responsible about more than 70% of cases of plant failure. We have proposed long time ago a mechanism for the development of this form of membrane fouling which explained several of its aspects :" Membrane Fouling Problems in Reverse Osmosis Desalination Applications " , Desalination & Water Reuse, V 10/3 ( 2000).
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Popular answers (1)
Al-Quds University
Because RO requires forcing the sea water through progressively smaller membranes it also requires a lot of energy for pumping.
It's obvious that the massive amounts of energy used in desalination contribute to climate change-causing greenhouse gas emissions, possibly exacerbating the local drought conditions that require use of desalination in the first place. There are additional issues with the incoming and outgoing (waste) water. Inlet water from the ocean often contains fish and other sea life and passing through the desalination plant kills these organisms. Slowing the speed of the inlet water by using larger pipes can allow fish to escape by simply swimming back out.
On the outlet side the effluent of desalination plants is a brine that is far too salty for the marine life that it comes into contact with. Some desalination plants create sea salt for additional revenue, eliminating the need for any effluent. Another solution is to dilute the brine with the cooling water of a nearby power plant, or just with ocean water.
All desalination processes produce large quantities of a concentrate, which may be increased in temperature, and contain residues of pretreatment and cleaning chemicals, their reaction byproducts, and heavy metals due to corrosion. Chemical pretreatment and cleaning are a necessity in most desalination plants, which typically includes the treatment against biofouling, scaling, foaming and corrosion in thermal plants, and against biofouling, suspended solids and scale deposits in membrane plants.
Hoping this will be helpful,
Rafik
3 Recommendations
All Answers (5)
Sidi Mohamed Ben Abdellah University
je crois que le problème majeur d'utilisation des membranes d'osmose inverse c'est le colmatage. c'est pour quoi il faut faire un prétraitement , filtre à sable, filtre à cartouche...., avant chaque traitement, et il faut également effectuer un lavage du pilot après utilisation.
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Al-Quds University
Because RO requires forcing the sea water through progressively smaller membranes it also requires a lot of energy for pumping.
It's obvious that the massive amounts of energy used in desalination contribute to climate change-causing greenhouse gas emissions, possibly exacerbating the local drought conditions that require use of desalination in the first place. There are additional issues with the incoming and outgoing (waste) water. Inlet water from the ocean often contains fish and other sea life and passing through the desalination plant kills these organisms. Slowing the speed of the inlet water by using larger pipes can allow fish to escape by simply swimming back out.
On the outlet side the effluent of desalination plants is a brine that is far too salty for the marine life that it comes into contact with. Some desalination plants create sea salt for additional revenue, eliminating the need for any effluent. Another solution is to dilute the brine with the cooling water of a nearby power plant, or just with ocean water.
All desalination processes produce large quantities of a concentrate, which may be increased in temperature, and contain residues of pretreatment and cleaning chemicals, their reaction byproducts, and heavy metals due to corrosion. Chemical pretreatment and cleaning are a necessity in most desalination plants, which typically includes the treatment against biofouling, scaling, foaming and corrosion in thermal plants, and against biofouling, suspended solids and scale deposits in membrane plants.
Hoping this will be helpful,
Rafik
3 Recommendations
Shiraz University
High ionic concentrations result in very high osmotic pressures which cause very low water fluxes and also fouling problems due to the presence of sulphate ion in sea water are among the most serious problems encountered.
2 Recommendations
National Research Center, Egypt
Prof Dr Gamal Khedr
Dear Mr Abdullah Albiladi
Our published research works showed that the main membrane problem in RO and NF applications, in the hot countries of the Middle East and the Arabian Gulf , is bio/organic fouling .It is found to be responsible about more than 70% of cases of plant failure. We have proposed long time ago a mechanism for the development of this form of membrane fouling which explained several of its aspects :" Membrane Fouling Problems in Reverse Osmosis Desalination Applications " , Desalination & Water Reuse, V 10/3 ( 2000).
1 Recommendation
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