Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

ION EXCHANGE COST ESTIMATE 1

Status
Not open for further replies.

gomirage

Civil/Environmental
Oct 4, 2003
53
Can anyone help me find ballpark figure on “ion exchange” water treatment plant cost? This is for drinking water softening application. Plant will be 1 MGD.

I will appreciate if I can have dollar figure per 1000 of gallon capacity. I have been looking on the net but can find any good source.

Thank you.

Chris
 
Replies continue below

Recommended for you

What type of softening? Cold lime or lime-soda? Sodium cycle ion exchange? Nanofiltration?

Be warned that free cost estimates are worth about as much as the effort you have put into them. Too many site and water specific variables to take into account.
 
i am looking for sodium cycle ion exchange.
 
You won't find the answer you are looking for on the internet. You need to provide a whole lot more information on the water to be treated. Complete water analysis, service flow rate in gallons per minute, cost of water and cost of salt. We can be of some help with that minimal information. Even then without more information the cost you will get will be "Deep Left Field of the Ballpark".

Gary Schreiber, CWS VI
The Purolite Co.
 
Gary is right. Not knowing the hardness and TDS of the raw water, leaves a lot to chance. But here is some information that might be helpful to you.

Using three 78" diameter by 72" side shell pressure vessels loaded with 100 cubic feet of cation resin to a depth of 36" will allow you to operate at a combined flow rate of 1 MGD based upon a hydraulic loading capacity of 7 gpm/sf. When one unit drops off line to regenerate, the loading through the other two units is 10.5 gpm/sf for approximately 1-1/2 hours. If hardwater blending is used, the loading will be even less in both cases. Typically, raw (hard) water is blended with softened water to produce an effluent containing about 85 mg/L of total hardness (in municipal drinking water systems).

When each softener vessel regenerates, it will consume approximately 500 - 1,000 pounds of salt and produce about 10,000 gallons of liquid waste. The frequency of regeneration will depend upon the hardness of the raw water. Once you know the hardness of the raw water, you can calculate the approximate capacity by converting the hardness (expressed as mg/L or ppm, as CaCO3) to grains per gallon by dividing by 17.1. Then divide this number into the capacity of the softeners, in this case, approximately 2 million to 2.7 million grains per softener vessel.

The cost for three individually skid mounted softener vessels with media, automatic valves and controls is approximately $75,000, plus shipping, installation, and startup.

The cost for a bulk salt storage/brinemaker silo with a capacity of approximately 36 tons and automatic level controls is roughly $25,000, plus shipping and installation.

The resin will last anywhere from 10 - 20 years, depending upon raw water quality and operating conditions. Resin replacement cost for the total system is about $10,000, plus installation costs.

Other than salt, water and resin replacement costs; there could be periodic repairs/replacement of valves and controls over years of operation, and the bulk salt storage silo may need to be vacuumed out after 5 - 10 years, depending upon the quality of salt used.

If raw water contains iron in excess of 0.3 mg/L, or manganese greater than 0.05 mg/L, or free chlorine in excess of 2 mg/L; then resin life and capacity can be seriously compromised. Without proper pretreatment to reduce these contaminants, frequent cleaning with acid-based reducing compounds and/or resin replacement will be eminent.

This estimate covers equipment only. There are other components such as site work, building costs, foundations, waste disposal, security, permitting, etc.


S. Bush
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor