AWWA JAW65358

Zinc orthophosphate has been used for many yearsas a corrosion inhibitor without a true understandingof its actual contribution to corrosion control. Thisstudy examined whether reduced or nonzincorthophosphate is as effective as zinc orthophosphatefor protection of piping materials.The authors reviewed the literature as well as casestudies of utilities that had switched from zinc to nonzinccorrosion inhibitors. Pilot-testing was then conductedat six New Jersey water treatment plants toassess the effect of corrosion inhibitors with and withoutzinc on new metal coupons.For protection of metal pipes, zinc does not appearto play an important role. Orthophosphoric acid wasfound to be as effective as zinc orthophosphate forprotection of metal piping materials and is less expensiveon a phosphate basis. In addition, converting fromzinc orthophosphate to a nonzinc alternative translatesinto less zinc that is released into the environment ormust be removed from wastewater. Includes 15 references, tables.

Product Details

Edition:

Vol. 99 - No. 11

Published:

11/01/2007

Number of Pages:

11

File Size:

1 file , 220 KB