Decontamination and toxicity removal of an industrial effluent containing pesticides via multistage treatment: Coagulation-flocculation-settling and photo-Fenton process

Abstract This paper evaluates the combination of coagulation-flocculation-settling and photo-Fenton for the decontamination of a real effluent containing ametrine ([AMT]=403 mg L−1), atrazine ([ATZ]=2153 mg L−1), imidacloprid ([IMD]=2936 mg L−1) and tebuthiuron ([TBT]=3354 mg L−1) and which is generated during the manufacturing process of pesticides. Physicochemical treatment (coagulation-flocculation-settling) was tested using different concentrations of Al(NO3)3 and Fe(NO3)3. No significant removal was achieved using Al(NO3)3 as coagulant while best results were obtained via coagulation with Fe(NO3)3 (99 % removal of color and turbidity). Pesticides remaining in the supernatant after coagulation-flocculation-settling stages were removed via photo-Fenton under black-light or solar irradiation. 82–95 % removal of target pesticides were obtained after photo-Fenton treatment (2 mmol L−1 of FeOx, 5463 mg L−1 of H2O2) using black-light lamps (400 kJ m−2). Solar irradiation improved the degradation of target pesticides (>99 %) leading to concentrations below quantification limits (