Full Description

A pilot scale (111 L) flow-through reactor equipped with 6 X 1 kW medium-pressure ultraviolet (UV) lamps was utilized at the Mannheim Water Treatment Plant in Kitchener, Ontario, Canada to investigate the impact of medium-pressure UV irradiation on the removal or formation of disinfection byproduct presursors during drinking water treatment. The UV pilot reactor was installed after ozonation and biological filtration but before final disinfection with chlorine. Samples were taken under various water quality and operational conditions and subjected to Uniform Formation Condition (UFC) testing to estimate final total trihalomethane (TTHM) and haloacetic acid (HAA9) concentrations. The experiments demonstrated that medium-pressure UV alone did not have a measurable effect on the THM and HAA9 precursors and did not change the chlorine demand after 24 h chlorination. However, under the condition of added hydrogen peroxide plus ultraviolet irradiation, the TTHM and HAA9 concentrations increased approximately linearly with UV dose up to a maximum of 2000 mJ/cm2. At a dose of 100 mJ/cm2, expected to be the maximum UV dose applied during drinking water treatment and with H2O2 doses ranging from 3.6 mg/L to 51 mg/L, increases ranged from 2% to 7% for the TTHM concentrations and from 2% to 6% for the HAA9 concentrations compared to no UV application.

Product Details

Published: 01/01/1999 ISBN(s): 1583210016 Number of Pages: 18File Size: 1 file , 350 KB