Remediation of the landfill leachate of Fez city (Morocco) by sono-photo-Fenton process: Cost and phytotoxicity assessment

A new Advanced Oxidation process (AOP) using the ultrasound-photo-Fenton process (US-P-FP) was used to treat stabilized landfill leachate from Fez City (Morocco). The effectiveness of the US-P-FP for landfill leachate treatment was investigated in terms of COD, UV254, and color removal. The operating factors (Fe2+ dosage, pH, H2O2 dosage, ultrasonic (US), UV-A) were optimized by the two-level factorial design. The findings reveal that the highest removal of COD, UV254, and color from the landfill leachate was 93 %, 77 %, and 98 %, respectively, at the optimum operation conditions [Fe2+] = 446 mg/L, [H2O2] = 250 mg/L and a pH = 3 in the presence of both US and UV-A irradiations. The phytotoxicity assessment of untreated and sono-photo-Fenton treated leachate samples was conducted through seed germination and root elongation tests using Medicago sativa seeds as bioindicators. The experimental results showed that the ultrasound-photo-Fenton process allowed a significant phytotoxicity reduction. Overall, the sono-photo-Fenton process proves to be a viable and efficient method for landfill leachate treatment.