Tags

Type your tag names separated by a space and hit enter

Mineralization of humic acids (HAs) by a solar photo-Fenton reaction mediated by ferrioxalate complexes: commercial HAs vs extracted from leachates.
Environ Sci Pollut Res Int. 2018 Oct; 25(28):27783-27795.ES

Abstract

The mineralization of bio-recalcitrant humic acids (HAs) by a solar photo-Fenton (SPF) process was investigated in aqueous system, in order to understand its abatement in real high-HA content matrices, such as sanitary landfill leachates. SPF reactions were performed in tubular photoreactors with CPCs at lab-scale (simulated solar light) and pilot-scale (natural sunlight). Considering the experimental conditions selected for this work, the formation of insoluble HA-Fe3+ complexes was observed. Thus, to avoid HA precipitation, oxalic acid (Ox) was added, since Fe3+-Ox complexes present a higher stability constant. The effect of different process variables on the performance of SPF reaction mediated by ferrioxalate complexes (SPFF) was assessed with excess of H2O2 (50-250 mg L-1), at lab-scale: (i) pH (2.8-4.0); (ii) initial iron concentration (20-60 mg Fe3+ L-1); (iii) iron-oxalate molar ratio (Fe3+-Ox of 1:3 and 1:6); (iv) temperature (20-40 °C); (v) UV irradiance (21-58 WUV m-2); and (vi) commercial-HA concentration (50-200 mg C L-1). At the best lab conditions (40 mg Fe3+ L-1, pH 2.8, 30 °C, 1.6 Fe3+-Ox molar ratio, 41 WUV m-2), commercial HAs' mineralization profile was also compared with HAs extracted from a sanitary landfill leachate, achieving 88 and 91% of dissolved organic carbon removal, respectively, after 3-h irradiation (8.7 kJUV L-1). Both reactions followed the same trend, although a 2.1-fold increase in the reaction rate was observed for the leachate-HA experiment, due to its lower humification degree. At pilot-scale, under natural sunlight, 95% HA mineralization was obtained, consuming 42 mM of H2O2 and 5.9 kJUV L-1 of accumulated UV energy. However, a pre-oxidation during 2.8 kJUV L-1 (12 mM H2O2) was enough to obtain a biodegradability index of 89%, showing the strong feasibility to couple the SPFF process to a downstream biological oxidation, with low chemicals and energetic demands. Graphical abstract ᅟ.

Authors+Show Affiliations

Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal. Instituto de Química, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Muller, 1555, CP 549, Campo Grande, MS, 79074-460, Brazil.Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal. tania.silva@fe.up.pt.Instituto de Química, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Muller, 1555, CP 549, Campo Grande, MS, 79074-460, Brazil.Instituto de Química, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Muller, 1555, CP 549, Campo Grande, MS, 79074-460, Brazil.Instituto de Química, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Muller, 1555, CP 549, Campo Grande, MS, 79074-460, Brazil.Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal. vilar@fe.up.pt.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

29546512

Citation

Santos, Ana P F., et al. "Mineralization of Humic Acids (HAs) By a Solar photo-Fenton Reaction Mediated By Ferrioxalate Complexes: Commercial HAs Vs Extracted From Leachates." Environmental Science and Pollution Research International, vol. 25, no. 28, 2018, pp. 27783-27795.
Santos APF, Souza BM, Silva TFCV, et al. Mineralization of humic acids (HAs) by a solar photo-Fenton reaction mediated by ferrioxalate complexes: commercial HAs vs extracted from leachates. Environ Sci Pollut Res Int. 2018;25(28):27783-27795.
Santos, A. P. F., Souza, B. M., Silva, T. F. C. V., Cavalcante, R. P., Oliveira, S. C., Machulek, A., Boaventura, R. A. R., & Vilar, V. J. P. (2018). Mineralization of humic acids (HAs) by a solar photo-Fenton reaction mediated by ferrioxalate complexes: commercial HAs vs extracted from leachates. Environmental Science and Pollution Research International, 25(28), 27783-27795. https://doi.org/10.1007/s11356-018-1561-x
Santos APF, et al. Mineralization of Humic Acids (HAs) By a Solar photo-Fenton Reaction Mediated By Ferrioxalate Complexes: Commercial HAs Vs Extracted From Leachates. Environ Sci Pollut Res Int. 2018;25(28):27783-27795. PubMed PMID: 29546512.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Mineralization of humic acids (HAs) by a solar photo-Fenton reaction mediated by ferrioxalate complexes: commercial HAs vs extracted from leachates. AU - Santos,Ana P F, AU - Souza,Bianca M, AU - Silva,Tânia F C V, AU - Cavalcante,Rodrigo P, AU - Oliveira,Silvio C, AU - Machulek,Amílcar,Jr AU - Boaventura,Rui A R, AU - Vilar,Vítor J P, Y1 - 2018/03/15/ PY - 2017/11/16/received PY - 2018/02/13/accepted PY - 2018/3/17/pubmed PY - 2019/1/4/medline PY - 2018/3/17/entrez KW - Biodegradability KW - Ferrioxalate complexes KW - Landfill leachates KW - Solar-driven photo-Fenton SP - 27783 EP - 27795 JF - Environmental science and pollution research international JO - Environ Sci Pollut Res Int VL - 25 IS - 28 N2 - The mineralization of bio-recalcitrant humic acids (HAs) by a solar photo-Fenton (SPF) process was investigated in aqueous system, in order to understand its abatement in real high-HA content matrices, such as sanitary landfill leachates. SPF reactions were performed in tubular photoreactors with CPCs at lab-scale (simulated solar light) and pilot-scale (natural sunlight). Considering the experimental conditions selected for this work, the formation of insoluble HA-Fe3+ complexes was observed. Thus, to avoid HA precipitation, oxalic acid (Ox) was added, since Fe3+-Ox complexes present a higher stability constant. The effect of different process variables on the performance of SPF reaction mediated by ferrioxalate complexes (SPFF) was assessed with excess of H2O2 (50-250 mg L-1), at lab-scale: (i) pH (2.8-4.0); (ii) initial iron concentration (20-60 mg Fe3+ L-1); (iii) iron-oxalate molar ratio (Fe3+-Ox of 1:3 and 1:6); (iv) temperature (20-40 °C); (v) UV irradiance (21-58 WUV m-2); and (vi) commercial-HA concentration (50-200 mg C L-1). At the best lab conditions (40 mg Fe3+ L-1, pH 2.8, 30 °C, 1.6 Fe3+-Ox molar ratio, 41 WUV m-2), commercial HAs' mineralization profile was also compared with HAs extracted from a sanitary landfill leachate, achieving 88 and 91% of dissolved organic carbon removal, respectively, after 3-h irradiation (8.7 kJUV L-1). Both reactions followed the same trend, although a 2.1-fold increase in the reaction rate was observed for the leachate-HA experiment, due to its lower humification degree. At pilot-scale, under natural sunlight, 95% HA mineralization was obtained, consuming 42 mM of H2O2 and 5.9 kJUV L-1 of accumulated UV energy. However, a pre-oxidation during 2.8 kJUV L-1 (12 mM H2O2) was enough to obtain a biodegradability index of 89%, showing the strong feasibility to couple the SPFF process to a downstream biological oxidation, with low chemicals and energetic demands. Graphical abstract ᅟ. SN - 1614-7499 UR - https://www.unboundmedicine.com/medline/citation/29546512/Mineralization_of_humic_acids__HAs__by_a_solar_photo_Fenton_reaction_mediated_by_ferrioxalate_complexes:_commercial_HAs_vs_extracted_from_leachates_ L2 - https://dx.doi.org/10.1007/s11356-018-1561-x DB - PRIME DP - Unbound Medicine ER -