Michael G. Stevens

Senior Staff Scientist

Ashland Inc.

 Sodium hypochlorite has rapidly replaced chlorine as the material of choice to treat waste water in North America.  There are many options for materials of construction to store this material at the waste water treatment facilities.  Fiberglass reinforced polymers has been used successfully over the years as an economical material of construction.  There are many different resins that can be used for this which has been giving varying lifetime of the tanks.  A study was conducted to identify the best resin to use for these storage tanks.  This study included laboratory coupon testing at 50°C and 65°C.  Coupons were also placed in sodium hypochlorite storage tanks at two waste water treatment facilities in Colorado for 12 months.  The results of this testing will be reported with recommendations for the system that should give the longest service life in sodium hypochlorite.