Study of pH effects on the evolution of properties of brown-water natural organic matter as revealed by size-exclusion chromatography during photocatalytic degradation

► The NOM photocatalytic degradation follows a preferential removal of fractions. ► The pH changes affect the adsorption and the photocatalytic mechanism of NOM. ► The pH changes do not affect the preferential removal of NOM fractions. ► The efficiency of UV254 removal remained constant with or without NOM adsorption. ► The evolution of NOM degradation leads to reduction of AOX and THMs.