Biodegradability index enhancement of landfill leachates using a Solar Galvanic-Fenton and Galvanic-Fenton system coupled to an anaerobic aerobic bioreactor

Mature landfill leachate is among the most difficult effluents to treat because of its complex composition, low biodegradability index and high toxicity. In this study the performances of Galvanic Fenton (GF) and solar Galvanic Fenton (SGF) systems coupled to a biological reactor were evaluated for the remediation of landfill leachate. The SGF and GF systems showed an increase in biodegradability from 0.0022 to 0.1388 and 0.1014, respectively, at 1500 mg hydrogen peroxide (H2O2) L-1 and 30 min of hydraulic retention time (HRT). The GF/biological coupled treatment showed the best performance in chemical oxygen demand (COD) (66.6%), biochemical oxygen demand (BOD) (86.5%), toxicity (90.1%) and organic nitrogen (ON) (93.7%) removal. The GF and SGF effluent characterization by UV-Visible (Uv-Vis), infrared (IR) and fluorescence spectroscopy showed the breaking of aromatic rings and conjugated double bond via the oxidation process. The GF system can be applied to improve the biodegradability index (BI) of leachates and integrated in wastewater treatment prior to a conventional biological treatment.