1. Title, Journal and Authors
Title: “Preface to the special issue on Pressure Retarded Osmosis in Megaton Water System Project”
Journal: Desalination
Authors: Akihiko Tanioka
2. Summary
1, 2.
Because PRO has been verified to be available between concentrated salt water and pure water, it has become possible to establish a commercial salt generation plant by PRO. Many researchers have proposed a new membrane with high water flow to enable PRO between rivers and sea water.
Sidney Loeb's Pressure Restarded osmotic (PRO) paper (1975 Science and 1976 Journal of Membrane Science) gave the author a very strong impression because he proposed the cost of plant construction and power as well as the technology system.
According to Statkraft's prediction, PRO technology is profitable if the power density reaches 5W / m2.
Takeo Honda has developed a new membrane module system called "four division transducer" using CTA hollow fiber from Toyobo Co., Ltd. Modifying membrane modules was concluded to be the key to improving net output efficiency.
The author found that salt leaked from inside the membrane should be removed by reverse cleaning with pure water. The membrane used in the PRO bench scale plant was of the hollow fiber type. He also concluded that the internal structure of RO spiral modules with flat sheet membranes should be modified for RPO.
3.
The author divided the problems that need to be solved for PRO into three.
1. How to reduce the cost of obtaining purified water.
2. How to Develop Effective Films for PRO
3. How to Develop Effective Membrane Modules
The author has also organized three groups below to solve this problem.
1. Membrane Preparation (Development) Group
2. Membrane Performance Test and Simulation Group
3. Plant Test Group
The author concluded that removing the RO membrane system would give sufficient output power. To improve the efficiency of PROs,
1. Change CTA hollow fiber.
2. New effective film should be developed.
3. Sewage purification shall be done in a simple way.
And, author quoted several papers.
"Energy recovery by PRO in sea water desalination plant"
The results of the prototype PRO plant with 10ich CTA hollow fiber module are presented, the maximum power density of 13.5 W / m2 was obtained and the economic efficiency of the system between salt water and sewage was discussed.
"Macro and Nano behabior of salt water in Pressure Retired Osmosis membrane module"
The flow of salt water in hollow fiber module and water behavior in membrane were simulated.
"Novel Membrane Development in Pressure Retired Osmosis: Ultrathin Semipermeable Membrane Based on Cross-linked Polybenzimidazole"
The author of the paper developed membrane material by using interconnected polybenzimiddazole, and tried to prepare hollow fiber (fiber with inner pores).
"PRO follow fiber membrane module and its characteristics"
Success of Prototype PRO Plant with 10-inch Toyobo CTA hollow fiber module
4.
Commercial salt water development using PRO is possible because it has been proved that 10 inch hollow fiber membrane module is available without low pressure RO membrane manipulation between salt water and purified water.
The novel PRO membranes is required, which had high water flux, should be developed if researchers completed the PRO between sea water and river water.
3. Originality and Creativity
4. Application to research
5. Contact
Yeong Gyu Gu / Intern student
Environmental Systems Engineering Lab.
School of Earth Sciences and Environmental Engineering
Gwangju Institute of Science and Technology
1 Oryong-dong Buk-gu Gwangju, 500-712, Korea
Phone : +82-10-6589-6653
E-mail : kududrb1@naver.com