Use of Chemicals in RO-Unit

thank you so much sir.

now its confirm what I was thinking.

thanks again,

regards,

Tanveer Ahmed

The membranes of an RO used for water have two types of membranes cellulose acetate and polyamide. The polyamide is now the more common type. Typically the ph is lowered by the addition of sulfuric acid to 6.0 t0 6.6 There are low pH alarms on them that will shut off the RO and you better be sure the metering pump supplying the acid does so at the same time to protect the membranes as they can be damaged by a pH less than 4.5 The reason for acidifiying the water before treatment is to prevent salts from percipitating on the membranes and plugging them thus reducing output. Bisulfite is added to neutralize (reduce)the chlorine in the water. Chorine will attack the polyamide membrane. Antiscalant and phosphates are only used in the cleaning solution to periodically clean the membranes. Systems and methods for cleaning vary with equipment. I've operated ROs for 25 years and for several applications besides water pretreatment. The calcium is sometimes added to adjust the pH up and improve taste if drinking is the intended use.

thank you sir for your help.

IM fresh candidate in this field. now im in KSA and doing Saudi Aramco project for Upgrading drinking water facilities.

your experience and help will be so helpful for me.

can i get your email address??

best regards,

Tanveer AHmed

my email address is peckerson@neb.rr.com Glad to help. Paul

You might find some useful information at:

http://www.dow.com/liquidseps/service/lm_design.htm

I am in the process of doing the IQ,OQ,PQ on our RO water system. The maintenance is handled by Pure Flow. Most of these chemicals are used (in our system) during the washing of the RO section of our system. The membranes are washed with acid one time then a base the next. we also use a bleach for sanitizing and carbon beds to remove the bleaching and fluoride from the city water. Contact me if you wish to go over some more process operations.