Removal of pesticides from drinking water by granular activated carbon

This dissertation investigates the adsorption dynamics of micropollutants, particularly pesticides, in drinking water treatment using granular activated carbon. The study examines the physicochemical properties and biotransformation potential of selected pesticides through various databases and analytical tools. Additionally, the likelihood of pesticides for biodegradation during the water treatment processes was investigated. Adsorption characteristics were assessed through batch experiments to determine kinetic and isotherm parameters. The results indicate that the adsorption of selected pesticides follows pseudo-second order kinetics. Isotherm analyses revealed that all pesticides exhibit a strong affinity for GAC, with chlorpyrifos and cyprodinil demonstrating the highest adsorption capacities. However, pesticide affinity decreased in the presence of background natural organic matter (NOM). The breakthrough behavior of pesticides in GAC columns was investigated using Rapid Small-Scale Column Tests (RSSCTs) under continuous-flow conditions. These experiments explored the effects of GAC particle size and empty bed contact time (EBCT), the presence of NOM, and competition on breakthrough behavior under different test conditions. Furthermore, the adsorption design software (AdDesignS) was used to estimate breakthrough curves based on batch isotherm parameters under various conditions. The predicted breakthrough curves demonstrated reliable accuracy in modeling GAC column performance. The findings of this research contribute to the optimization of adsorption-based water treatment processes and provide valuable insights for preliminary system design.