Reverse Osmosis 1

[linus2003]

I am kind of a novice in the field of water treatment. I am wokring in the field of hazardous waste and has a client who has a question regarding reverse osmosis process. Apparently, he is acquiring some interests in some wells, the water from which is being subjected to reverse osmosis treatment. Where can I find more information on this process? Is it like a state-of-the art method of treating drinking water? I have heard of granular activated carbon, but not reverse osmosis. Can someone please enlighten me on this process. Thanks.

 

[saxon]

linus, R.O. is essentially an ionic filtration unit, that operates at the 0.001 micron range or at 10 angstroms level and below. Do a web search for Osmonics Inc. They'll fill you in on all the details.

Hope this helps.
saxon

 

[Nosey]

Also try

http://www.watertreatmentguide.com/

http://www.membranes.com/

http://www.eawater.com/html/drh2o/ro.htm

Regards

Nosey

 

[kris44]

From what i remember from my chemistry days, a simple answer to reverse osmosis is,
there are two sides seperated by a semipermeable membrane, one with solvent and one with pure solvent. A pressure greater than the osmotic pressure (osmotic pressure is the pressure required to stop the flow of solvent) is applied to the solution side of the semipermeable membrane. This application of pressure increase the rate at which solvent molecules leave the solution and thus reverses the flow of solvent, forcing it to flow from solution to pure solvent. I think it's due to Le Chatelier's principle, by applying a pressure you reverse the reaction.

 

[Nosey]

I should also have mentioned the following resource within this fine website.

Membrane engineering Forum (forum136)

 

[Tellabs]

Unlike water filtration, that can only remove some suspended materials larger than 1 micron, the process of reverse osmosis (RO) will eliminate the dissolved solids, bacteria, viruses and other germs contained in the water. RO is essentially a pressure driven membrane diffusion process for separating dissolved solutes. The RO is generally used for desalination seawater for its conversion into potable water. The salient features of the process are that it involves no phase change and it is relatively a low energy process.
Almost all RO membranes are made polymers, cellulosic acetate and matic polyamide types rated at 96%-99+% NaCl rejection. RO membranes are generally of two types , asymmetric or skinned membranes and thin film composite (TFC) membranes. The support material is commonly polysulfones while the thin film is made from various types of polyamines, polyureas etc.
RO membranes have the smallest pore structure, with pore diameter ranging from approximately 5-15 A0 (0.5 nm - 1.5 nm). The extremely small size of RO pores allows only the smallest organic molecules and unchanged solutes to pass through the semi-permeable membrane along with the water. Greater than 95-99% of inorganic salts and charged organics will also be rejected by the membrane due to charge repulsion established at the membrane surface.