| Autor: |
Prado, L. L., Melo, V. F., Braga, M. C., Motta, A. C. V., Araújo, E. M. |
| Předmět: |
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| Zdroj: |
International Journal of Environmental Science & Technology (IJEST); Aug2023, Vol. 20 Issue 8, p9129-9142, 14p |
| Abstrakt: |
Landfill leachates and sewage sludge are environmental contaminants that challenges urban sustainability. It was evaluated the use of sewage sludge thermally treated by pyrolysis (450 °C) as an adsorbent of N-NH4+ from landfill leachates. Samples of landfill leachates and sewage sludge were collected in southern Brazil. Sorption experiments were performed using pyrolyzed sludge (PSS) and commercial activated carbon (as reference material), with landfill leachate as the solution source of N-NH4+. Citric acid was used in the desorption experiments. The chemical composition, specific surface area, and porosity of PSS was determined, and infrared spectroscopic analysis with Fourier transformation was performed. The PSS presented a maximum N-NH4+ adsorption capacity of 14.8 mg g−1, with abundant carboxylic groups and a high specific surface area (30.4 m2 g−1). The landfill leachate contained 445.8 mg L−1 of N-NH4+, and the PSS was able to remove 16% of it in the sorption experiment, with a 60% saturation of the pyrolyzed sludge adsorption sites. A pH change from 4 to 7 increases pyrolyzed sludge adsorption due to negative charge formation (the zero charge point (pHZCP) of PSS = 6). Another factor that favored N-NH4+ adsorption was the low pyrolysis temperature (450 °C) that preserved the –O–H (3400 cm−1) and Si–OH (1040 cm−1) functional groups. The entropy parameter (ΔS) of 0.42 kJ mol−1 combined with a negative ΔG° indicates affinity between the PSS and N-NH4+. Of the N-NH4+ adsorbed by the PSS, only 19% was desorbed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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