Simultaneous regeneration of activated carbon and removal of adsorbed atrazine by ozonation process: From laboratory scale to pilot studies

A novel treatment technique by coupling granular activated carbon (GAC) adsorption and ozone regeneration was constructed for long-lasting water decontamination. The GAC adsorption showed high performance for atrazine (ATZ) removal (99.9 %), and the ozone regeneration ensured the recyclability of GAC for water purification. The regeneration process was evaluated via several paths to assist the efficient adsorption process. Employing ozone micro-nano bubbles (O3-MNBs) for regenerating GAC showed superior performance compared to traditional ozone. Meantime, inhibiting the formation of bromate (BrO3−). ATZ adsorption process suffered from the pore-filling, hydrogen bonding effect and π-π EDA interaction. The surface phenolic hydroxyl group, carboxyl group and pyridine nitrogen benefitted the triggering of ozone to generate reactive oxygen species, and regenerate the GAC surface. The superior performance of the adsorption and regeneration process was verified via a long-term running by a pilot study. It significantly improved the removal of organic micropollutants, UV254 and permanganate index. Additionally, the intermittent O3-MNBs regeneration process resulted in efficient decontamination within the pores structure of GAC, which also effectively preserved the pore structure from destruction. For actual application, the cost of water production can be saved around 0.63 kWh m−3. This work proposed new ideas and theoretical support for economic water production.