Removal of organic matter and ammoniacal nitrogen from landfill leachate using the UV/H₂O₂ photochemical process

ABSTRACT

This study investigates the effects of pH, H₂O₂ concentration and reaction time of the UV/H₂O₂ photochemical process on the removal of organic matter and ammonia from biologically pre-treated landfill leachates in anaerobic stabilization ponds. The results show that the concentration of H₂O₂ and the initial pH are significant factors, with no significant interaction between them. A pH of 3 is the optimum value for the UV/H₂O₂ process for the removal of organic matter, resulting in 51.63% chemical oxygen demand (COD) removal in addition to the removal of aromatic compounds. The N-NH₃ removal showed little variation between pH values of 1, 5, 7, 11 and 13; the removal was on the order of 16.43 ± 2.00%. The consumption of H₂O₂ was elevated at pH 9, 11 and 13; at these pH values, the average removal was 94.56 ± 0.43%, compared to 43.07% at pH 3. First-order polynomial models and reaction times on the order of 15 min are sufficient for optimization studies and for evaluation of the effects of the studied parameters. The results of this study support the optimization of the UV/H₂O₂ process for the removal of organic matter and ammonia from landfill leachates.

KEYWORDS:

• Advanced oxidative process
• UV/H₂O₂
• landfill leachate
• municipal solid waste
• hydrogen peroxide

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgements

The authors would like to thank UFSC and IFSC for institutional support and the National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq) and the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES) for financial support of the research.

ORCID

Rolando Nunes Córdova http://orcid.org/0000-0002-4427-9635

Maria Eliza Nagel-Hassemer http://orcid.org/0000-0002-7732-7218

William Gerson Matias http://orcid.org/0000-0002-2386-0578

Jose Miguel Muller http://orcid.org/0000-0003-0349-2269

Armando Borges de Castilhos Junior http://orcid.org/0000-0003-0455-2585

Additional information

Funding

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES.