Title |
Pyrolysis of Solid Digestate from Sewage Sludge and Lignocellulosic Biomass: Kinetic and Thermodynamic Analysis, Characterization of Biochar |
ID_Doc |
14226 |
Authors |
Petrovic, A; Vohl, S; Predikaka, TC; Bedoic, R; Simonic, M; Ban, I; Cucek, L |
Title |
Pyrolysis of Solid Digestate from Sewage Sludge and Lignocellulosic Biomass: Kinetic and Thermodynamic Analysis, Characterization of Biochar |
Year |
2021 |
Published |
Sustainability, 13, 17 |
DOI |
10.3390/su13179642 |
Abstract |
This study investigates the pyrolysis behavior and reaction kinetics of two different types of solid digestates from: (i) sewage sludge and (ii) a mixture of sewage sludge and lignocellulosic biomass-Typha latifolia plant. Thermogravimetric data in the temperature range 25-800 degrees C were analyzed using Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose kinetic methods, and the thermodynamic parameters (Delta H, Delta G, and Delta S) were also determined. Biochars were characterized using different chemical methods (FTIR, SEM-EDS, XRD, heavy metal, and nutrient analysis) and tested as soil enhancers using a germination test. Finally, their potential for biosorption of NH4+, PO43-, Cu2+, and Cd2+ ions was studied. Kinetic and thermodynamic parameters revealed a complex degradation mechanism of digestates, as they showed higher activation energies than undigested materials. Values for sewage sludge digestate were between 57 and 351 kJ/mol, and for digestate composed of sewage sludge and T. latifolia between 62 and 401 kJ/mol. Characterizations of biochars revealed high nutrient content and promising potential for further use. The advantage of biochar obtained from a digestate mixture of sewage sludge and lignocellulosic biomass is the lower content of heavy metals. Biosorption tests showed low biosorption capacity of digestate-derived biochars and their modifications for NH4+ and PO43- ions, but high biosorption capacity for Cu2+ and Cd2+ ions. Modification with KOH was more efficient than modification with HCl. The digestate-derived biochars exhibited excellent performance in germination tests, especially at concentrations between 6 and 10 wt.%. |
Author Keywords |
digestate; pyrolysis; kinetics; thermogravimetric analysis; biochar characterization; germination test; biosorption |
Index Keywords |
Index Keywords |
Document Type |
Other |
Open Access |
Open Access |
Source |
Science Citation Index Expanded (SCI-EXPANDED); Social Science Citation Index (SSCI) |
EID |
WOS:000694512900001 |
WoS Category |
Green & Sustainable Science & Technology; Environmental Sciences; Environmental Studies |
Research Area |
Science & Technology - Other Topics; Environmental Sciences & Ecology |
PDF |
https://www.mdpi.com/2071-1050/13/17/9642/pdf?version=1630072135
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