Determination, Interpretation and Modeling of Chlorination By-products Concentrations in Surface Waters

The formation of chlorination by-products (CBPs) was investigated by bench-scale chlorination experiments with surface waters from different sources in Lesvos island, Greece. The main factors studied were organic matter content of water (expressed as UV-272 absorbance), time and chlorine dose. The CBPs, determined by gas chromatographic techniques, belong to the categories of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles, chloral hydrate and chloropicrin. HAAs and THMs were the most abundant CBPs detected in the chlorinated samples, while haloketones, haloacetonitriles and chloral hydrate occurred at much lower concentrations. Statistical analysis of the results with multifactor analysis of variance revealed the influence of the parameters studied on the formation of individual compounds. Application of principal component analysis (PCA) provided a clear picture of the differentiations between varying water sources and chlorination conditions. Multiple regression was used for development of predictive models for CBPs formation. The proposed models are considered satisfactory for predicting CBPs concentrations for water sources and chlorination conditions similar to those examined.