SEASONAL-VARIATIONS IN HUMIC SUBSTANCES AND THEIR REDUCTION THROUGH WATER-TREATMENT PROCESSES

The apparent molecular mass concentrations of dissolved humic substances from the Detroit River and treated water from the Windsor Water Treatment Plant were determined by gel permeation chromatography over a 1-year period. The results of this research show significant seasonal variations in humic substance concentrations and these values are influenced by the turnover of water bodies. The gel permeation chromatograms of the samples indicate that there is a gradual reduction in the concentration of humic substances during the treatment process, the greatest change occurring after coagulation-sedimentation process. In this process, 76%, 40%, and 30% of the high. intermediate, and low molecular mass compounds, respectively, were either transformed in chemical composition or removed. Other parameters such as turbidity, chlorine demand (during prechlorination), and trihalomethanes concentration in the treated water were also analyzed and there appears to be a relationship between them. When the humic substance concentrations are high, generally the turbidity, chlorine demand, and total trihalomethanes concentrations in the drinking water are also high.