Two, 500-gallon water buffalo
Question: I’m responsible for maintaining a couple of [U.S. Army] Water Buffalo [water tanks]—500 gallons each. I was told that I should put chlorine in the water to keep it fresh. Can you tell me how much should I put in? Also, is there something else I could use? Keep in mind, this is for a county department (i.e., no money). Thank you for your help.
William T. Maxson, Deputy
Men’s Central Jail Training Unit
Los Angeles County Sheriff’s Department
Answer: Larry Henke, senior technical director at St. Louis Park, Minn.’s Robert B. Hill Co. and a member of WC&P’s Technical Review Committee, wrote an excellent article on this topic in our May 1999 issue (“Wells, Groundwater and Microbes: Pristine Maybe, But Not Necessarily as ‘Pure’ as the Driven Snow,” pp. 36-39). I would also suggest you contact Krudico Inc. (www.krudico.com) in Iowa or Better Water Industries in Tyler, Minn.—(507) 247-5929—for more information. Both specialize in water treatment for agriculture/livestock, particularly with respect to chlorination dispensing systems for wells or tanks. They’re likely going to recommend you use a pellet dispenser for dry chlorine tablets. (Osmonics, PPG Inc. and Severn Trent Services provide similar equipment). They may refer you to a dealer in your area that can assist you.
Silica & RO fouling
Question: We are an RO countertop water purification system manufacturer. There are four stages in our system—sediment, pre-GAC, RO membrane and post-GAC filters. The problem is that we sometimes found silicates (CaSiO4 or SiO2) at the pure water tank. Would you like to advise me?
P.W. Lee, CWS-I
Answer: We would first suggest you refer to an article by Peter Meyers, a former member of the WC&P Technical Review Committee who is with ResinTech of West Berlin, N.J.:
“Behavior of Silica in Ion Exchange and Other Systems,” by Peter Meyers, which was presented at the International Water Conference, held in Pittsburgh, PA October 18-20, 1999—see www.resintech. com/index.cfm?Point=TechArticles#3
Robert Slovak, a technical advisor to another magazine we publish, Agua Latinoamérica, is an expert on reverse osmosis systems and is also familiar with the problem of silica in membrane separation applications. He can be reached at email@example.com.
The following websites also had information regarding silica and RO fouling:
Hope that helps.