Full Description

In 1994 and 2001, US water providers were surveyed abouttheir use of phosphate inhibitors. Responses pointed towidespread use of phosphate inhibitors, including polyphosphate,orthophosphate, zinc orthophosphate, and phosphateblends. From 1994 to 2001, a number of respondents shifted frompoly/orthophosphate blends to orthophosphate, a trend viewed asbeneficial because polyphosphate compounds have been shownto be detrimental to metal corrosion under some circumstances.Although many water suppliers used phosphate inhibitors, fewconducted any scientific tests to determine the applicability ofinhibitors to their particular circumstances. In selecting a phosphateinhibitor, most utilities relied on vendor data or reports ofchemical success at another facility. Even at larger utilities, wheremanagers were aware of potential drawbacks of inhibitors, manydid not know the exact composition of the phosphate chemicalsthey were using.Survey results indicate that many utilities are incurring considerablecosts to add inhibitors without direct proof of the chemical'sefficacy in their particular water. Understanding how and whyinhibitors are used is the first step toward helping utilities developeffective strategies to meet the diverse goals of corrosion controland water quality. More support is also needed to help utilitiesmake informed decisions about inhibitor use. Water providers needto look at their phosphate inhibitor use, examine their reasons forusing phosphates, and base their phosphate selection on hard dataand their individual water conditions. Includes 44 references, tables, figures.

Product Details

Edition: Vol. 94 - No. 7 Published: 07/01/2002 Number of Pages: 7 File Size: 1 file , 230 KB