Performance assessment of micropollutants removal from water using advanced oxidation processes

Abstract

In a global climate change scenario, reliable access to clean and safe water for all remains a great worldwide challenge for the twenty first century, as one of the most ambitious targets of several Sustainable Development Goals (SDG) established in the UN Agenda 2030. The increasing presence in the urban aquatic ecosystems of priority pollutants and contaminants of emerging concerning (CECs) have brought new challenges to the existing water treatment systems (WTS) concerning with public health protection and the of drinking water sources preservation. Advanced oxidation processes (AOPs) have been widely studied because of their potential as a complementary or alternative process to conventional wastewater treatment. Several AOPs using nanomaterials as photocatalyst can be particularly effective in the degradation of many toxic micropollutants, and enhance the multifunctionality, versatility and sustainability of WTS. This work presents a synthesis of the major results obtained in several pilot and lab-scale studies aiming to assess the performance of different low-cost catalytic processes used for antibiotic and pesticide removal. For each photo-oxidation reactors, different test scenarios are defined in order to evaluate the effects of several abiotic and hydraulic parameters on process kinetics and removal efficiencies. The experimental results were very promising, because antibiotic removal efficiencies achieved the maximum value of 96% for the photo-oxidation by water columns with suspended TiO2 nanoparticles, and 98% for the photocatalytic filtration performed by a porous medium coated with TiO2. In the photoelectrocatalytic reactor, the atrazine concentration has been fully removed for reaction times between 35 and 95 minutes.