Trihalomethanes (THMs) are carcinogenic by-products of disinfection that are present in drinking water. In the present research, adsorption and photodegradation, either individually or in tandem, was employed for the removal of the principal THMs found in water supply systems. The effects of pH, contact time, adsorbents and adsorbate concentration on the adsorption system were investigated .The Langmuir and Freundlich adsorption isotherm models were used to analyze the resulting adsorption data. The photodegradation of the THMs solutions was undertaken by exposing each component for 25 min. to (i ) UV light alone or (ii) UV light in presence of activated carbon derived from olive stone or (iii) UV light in presence of activated carbon loaded by TiO2. The integration of adsorption and photodegradation systems as a hybrid treatment process resulted in a synergetic enhancement of the THM removal efficiency. The kinetics of THM removal were found to follow the pseudo-second-order model rather than the Langmuir–Hinshelwood pseudo-first-order model.