Photo-Fenton process as an efficient alternative to the treatment of landfill leachates

• Published in: Journal of hazardous materials Vol. 153; no. 1; pp. 834 - 842
• Main Authors: Primo, Oscar, Rivero, María J., Ortiz, Inmaculada
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2008; Elsevier
• Subjects: Advanced oxidation processes; Applied sciences; Chemical engineering; COD removal; Copper - chemistry; Exact sciences and technology; General treatment and storage processes; Hydrogen Peroxide - chemistry; Iron - chemistry; Landfill leachate; Oxidation-Reduction; Photo-Fenton process; Pollution; Reactors; Ultraviolet Rays; Waste Disposal, Fluid - methods; Wastes; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - radiation effects; Water Purification - methods; Advanced oxidation processes; Photo-Fenton process; Landfill leachate; COD removal; Waste dumping; Organic matter; Hydrogen peroxide; Biodegradability; Pollutant behavior; Ultraviolet radiation; Chemical oxygen demand; Water quality; Fenton reaction; Oxidation; Leachate; Photooxidation; Photochemical degradation; Neutralization
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2007.09.053

Advanced oxidation processes (AOPs), namely photo-Fenton, Fenton-like, Fenton and UV/H 2O 2, have been investigated in the removal of organic matter and colour from landfill leachates. The leachate was characterised by high COD, low biodegradability and intense dark colour. Evaluation of COD removal as a function of the operation variables (H 2O 2, Fe 2+, Cu 2+, UV) led to results that ranged between 30% and 77% and it was observed that the removal efficiencies decreased in the order: photo-Fenton > Fenton-like > Fenton > UV/H 2O 2 > UV. Thus, a detailed experimental analysis was carried out to analyse the effect of the hydrogen peroxide and iron concentrations and the number of reagent additions in the photo-Fenton process, observing that: (i) the COD removal ranged from 49% to 78% depending on the H 2O 2 dose, (ii) the total amount of organic matter removed was increased by adding the reagent in multiple steps (86%), (iii) iron concentration corresponding to a Fe 2+/COD mass ratio = 0.33 was found to be the most favourable and, (iv) after a neutralization step, the colour and residual concentrations of iron and H 2O 2 were practically negligible in the final leachate solution.