Granular activated carbon (GAC) adsorption of two representative taste and odor (T & O) compounds, 2-isopropyl-3-methoxy pyrazine (IPMP), and 2-isobutyl-3-methoxy pyrazine (IBMP), in drinking water was investigated. Results show that the modified Freundlich equation best fit the experimental data during the adsorption isotherm tests, and the pseudo first-order kinetics and intra-particle diffusion kinetics well described the adsorption kinetics pattern. The calculated thermodynamic parameters (ΔH0, ΔS0, and ΔG0) indicated a spontaneous and endothermic adsorption process. Factors affecting the treatment efficiency were carefully evaluated. Acidic and alkaline conditions both favored GAC adsorption of IPMP and IBMP, especially the former. With the GAC dosage increasing, the first order adsorption rates increased, while the intra-particle adsorption rates decreased. Within 12h, 200mg/L GAC could remove >90% of 150μg/L IPMP and IBMP via adsorption at pH 3-11. Therefore, GAC is a promising treatment technology to control the T & O compounds associated water pollution. Promising results show that granular activated carbon (GAC) is able to achieve a high removal of taste and odor compounds within few hours. The treatment efficiency depends on the GAC dose and solution pH. GAC could be a new and effective material to deal with emerging T & O issues frequently occurring in drinking water resources.
- 2-Isobutyl-3-methoxy pyrazine
- 2-Isopropyl-3-methoxy pyrazine
- Adsorption mechanism
- Drinking water