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[Display omitted] • TiO 2 -rGO at the solar assisted photodegradation of complex mixing of pesticides. • Best photocatalytic performances with oxygen, regardless of the water matrix. • H 2 O 2 has not improved the final photocatalytic efficiency in any case. • P25-rGO promoted the photo-oxidation of the complex pesticides mix studied. • HBK-rGO presented excellent solar photoefficiency with 200 μg L-1 of pesticides. New titania-reduced graphene oxide (TiO 2 -rGO) nanocomposites have been studied to assess their application in the solar assisted photodegradation of a complex mixing of pesticides (pyrimethanil, isoproturon, alachlor and methomyl) at solar pilot plant, opening the opportunity to extend the use of these hybrid photocatalysts to complex wastewater effluents. TiO 2 -rGO nanocomposites were prepared by hydrothermal method from two commercial TiO 2 , Hombikat UV-100 (HBK) and Aeroxide® P25 (P25). The effect of two different water matrices (simulated and natural) on TiO 2 -rGO solar photoefficiency with two pesticides concentrations (5 mg·L−1 and 200 μg·L−1), and the additional use of an electron scavenging as oxidant agent, such as hydrogen peroxide in a comparison with oxygen from air, has been studied in compound parabolic collectors (CPC) photoreactors. Best photocatalytic performances were always found with oxygen over both TiO 2 -rGO nanocomposites, regardless of the water matrix employed. The use of H 2 O 2 as oxidant agent has not improved the final photocatalytic efficiency in any case. The generation of secondary highly reactive species in the reaction media from reaction of SO 4 ●- /HO radicals, and the more negatively surface charge with low S BET of P25-rGO nanocomposite, besides its lower hydrodynamic size with lower particle aggregation in the reaction conditions, have been responsible to promote the photo-oxidation of the complex pesticides mix studied. Finally, HBK TiO 2 -reduced graphene oxide (HBK-rGO) nanocomposite has presented excellent solar photoefficiency in the photodegradation of 200 μg·L−1 of each pesticide with the oxygen form air, especially under natural water matrix, because of its large negatively charge surface area where probably recombination of electrons and holes is prevented. [ABSTRACT FROM AUTHOR]

Agricultural wastewater is characterized by high organic matter and traces of organic pollutants. Effluents from the agro-food industry in particular are a potentially high environmental risk which requires appropriate, comprehensive treatment. This study evaluated the treatment of real wastewater from an agro-food processing plant by an Immobilized Biomass Reactor working in batch and continuous operating modes. Organic matter oxidation and the removal of reference organic pollutants were analyzed. Finally, the efficiency of a photocatalytic tertiary treatment with supported TiO 2 for the IBR effluent containing persistent microcontaminants was also studied. After the combined treatment, imazalil and thiabendazole were completely removed and over 90% of acetamiprid had been eliminated, but only with the additional contribution of hydrogen peroxide as an electron acceptor. [ABSTRACT FROM AUTHOR]