Landfill leachate treatment by solar-driven AOPs

The optimal initial iron dose for the photo-Fenton treatment of the leachate is 60 mg Fe2+ L−1, which is in agreement with path length of 5 cm in the photoreactor. The kinetic behaviour of the process (60 mg Fe2+ L−1) comprises a slow initial reaction, followed by a first-order kinetics (k = 0.020 LkJUV-1, r0 = 12.5 mg kJUV-1), with H2O2 consumption rate of kH2O2 = 3.0 mmol H2O2kJUV-1, and finally, the third reaction period, characterized by a lower DOC degradation and H2O2 consumption until the end of the experiment, presumably due to the formation of low-molecular-weight carboxylic groups. A total of 306 mM of H2O2 was consumed for achieving 86% mineralization (DOCfinal = 134 mg L−1) and 94% aromatic content reduction after 110 kJUV L−1, using an initial iron concentration of 60 mg Fe2+ L−1.