Elution of bisphenol A and its chlorination by-products from lined pipes in water supply process

Elution of bisphenol A (BPA), chlorinated BPAs (i.e., 3-chlorobisphenol A, sum of 3,5-dichlorobisphenol A and 3,3′-dichlorobisphenol A, 3,3′,5-trichlorobisphenol A, and 3,3′,5,5′-tetrachlorobisphenol A) and 2,4,6-trichlorophenol (TCP) from lined pipes coated with two epoxy resins were investigated in a 24-month continuous test passing tap water. BPA, chlorinated BPAs, and TCP were not detected in the tap water at the outlet of lined pipes in most cases. However, all of these chemicals were detected in the tap water after 16 h of retention. The sums of BPA and chlorinated BPAs in the retained tap water were usually high when the residual chlorine levels were low. The residual chlorine was related to temperature, residual chlorine in the tap water at the inlet of lined pipes, and the elapsed time. From the results of leach tests, it was indicated that no marked changes in BPA concentration over the 24 months of the continuous test. Chlorinated BPAs and TCP were accumulated on the surface of lined pipes during the continuous test.