Application of ultrasound and quartz sand for the removal of disinfection byproducts from drinking water

• DBPs with log Kow ⩾ 1.97 can be sonodegraded.
• More chlorine atoms in the DBPs molecular structure seems easier to be adsorbed.
• All the 12 targeted DBPs can be removed effectively by combined use of US and QS.
• Part of QS particles were corroded into small particles and play a catalytic role.
• Enhanced mass transfer rate leading to an improvement of QS adsorption efficiency.

To the best of our knowledge, little information is available on the combined use of ultrasound (US) and quartz sand (QS) in the removal of disinfection byproducts (DBPs) from drinking water. This study investigates the removal efficiency for 12 DBPs from drinking water by 20 kHz sonolytic treatment, QS adsorption, and their combination. Results indicate that DBPs with log Kow ⩽ 1.12 could not be sonolysized; for log Kow ⩾ 1.97, more than 20% removal efficiency was observed, but the removal efficiency was unrelated to log Kow. DBPs containing a nitro group are more sensitive to US than those that comprise nitrile, hydrogen, and hydroxyl groups. Among the 12 investigated DBPs, 9 could be adsorbed by QS adsorption. The adsorption efficiency ranged from 12% for 1,1-dichloro-2-propanone to 80% for trichloroacetonitrile. A synergistic effect was found between the US and QS on DBPs removal, and all the 12 DBPs could be effectively removed by the combined use of US and QS. In the presence of US, part of the QS particles were corroded into small particles which play a role in increasing the number of cavitation bubbles and reducing cavitation bubble size and then improve the removal efficiency of DBPs. On the other hand, the presence of US enhances the DBP mass transfer rate to cavitation bubbles and quartz sand. In addition, sonolytic treatment led to a slight decrease of pH, and TOC values decreased under all the three treatment processes.