E.coli inactivation Technology: general issues TiO2 UV-LED advanced oxidation advanced oxidation process antibiotics biological contaminants chemical oxygen demand circular economy computer-based learning cytotoxicity elimination routes emerging pollutants flower-like Bi2WO6 fresh urine graphene oxide heterogeneous photocatalysis hexacyanoferrate hydrothermal method kinetic modeling membrane technology micropollutants mining pharmaceutical degradation photocatalysis photoreactor design pollution processes selectivity reactive oxygen species (ROS)