THM formation during chlorination of treated municipal wastewaterTHM formation during chlorination of treated municipal wastewater Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-11-152002enChlorination batch experiments were conducted in order to estimate the concentration of THM and their formation potential in nitrified and partially nitrified secondary effluent. The role of contact time (up to 2 hours), chlorine dose (3 levels), pH and temperature on the formation of THM was evaluated. THM formation, as measured by individual concentration as well as formation potential, was high for the nitrified secondary effluent, while for the partially nitrified effluent the respective concentrations were low, due to the reaction of chlorine with ammonia to form chloramines. In general, THM concentrations progressively increased as contact time, pH and chlorine dose increased. Increase in temperature (from 15-25°C) showed a rather limited effect. In addition, coagulation tests were applied prior to chlorination of the nitrified effluent for removing organic carbon and thereby controlling the formation of THM. Alum was used as the coagulant in doses varying from 0.1 mM to 2.5 mM. As the coagulant dose increased, the removal of both DOC and absorbance at 254 nm increased, while THM formation decreased. The reduction in THM formation was more pronounced for coagulant doses higher than 1.5 mM. http://creativecommons.org/licenses/by/4.0/Water Science and Technology: Water Supply23235-242 Koukouraki Elisavet Κουκουρακη Ελισαβετ Diamantopoulos Evaggelos Διαμαντοπουλος Ευαγγελος IWA Publishing Domestic effluent Domestic sewage Domestic wastewater Effluent (Sewage) Industrial effluent Industrial wastewater Sewage effluent Waste water Waste waters Wastewater Wastewaters sewage domestic effluent domestic sewage domestic wastewater effluent sewage industrial effluent industrial wastewater sewage effluent waste water waste waters wastewater wastewaters