Understanding and exploring the potentials of household water treatment methods for volatile disinfection by-products control: Kinetics, mechanisms, and influencing factors

This study systematically evaluates the capabilities of five types of household water treatment (HWT) methods (including boiler heating, microwave irradiation, pouring, stirring, and shaking) on the removals of four regulated trihalomethanes (THM 4 ) and three iodinated halomethanes (IHMs) under a variety of conditions simulative of residential uses. Overall, the results clearly showed promising capabilities of all five HWT methods in controlling volatile disinfection by-products (DBPs), and heating with a boiler was the most effective approach among all methods due to the synergistic effects of water turbulence and bubbling phenomena. A contemporary boiler equipped with an automatic switch-off function reduced on average 92% of seven halomethanes (HM 7 ) at favourable conditions. The removal increased significantly with increasing initial concentrations and the rates correlated well with the logarithmic Henry’s law constants and molecular weights of compounds, with triiodomethane being the most refractory species. Meanwhile, the importance of water handling habits was revealed, including power input, operation time, volume, heating/cooling speed, cooling method, and capping conditions. The findings hence explored the potentials of HWTs on DBP control and pointed out a potential limit to DBP epidemiology studies that do not consider water handling habits.