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Simulation of carbon degradation in a rotary drum pilot scale composting process.
J Environ Manage. 2012 Oct 15; 108:1-7.JE

Abstract

This paper studies the simulation of carbon degradation in pilot scale solid waste composting processes using first-order kinetic models previously calibrated by laboratory experiments at different temperatures. Different solid biowastes (olive mill waste, winery waste, sewage sludge and reed biomass) were used. Three mixtures were prepared from combinations of the materials listed above, and they were used in both the laboratory kinetic experiments and the pilot scale composting experiments. Lab experiments were conducted in small reactors with temperature (T) control and forced aeration of the solid mixture. Each biowaste mixture was treated at four different temperatures, 25, 40, 50 and 60 °C, with controlled moisture; the carbon (C) concentration of the samples was measured weekly. Two different kinetic models were used to fit the carbon mineralisation curves: the 2C model, which considers two organic fractions (biodegradable and non-biodegradable), and the 3C model, which considers three fractions (easily biodegradable, slowly biodegradable and non-biodegradable). In both cases, the kinetic rate constants were calculated by mathematical fitting. The influence of temperature on the rate constants was also studied for both models using a T-dependent equation. The theoretical k(T) curves showed classical shapes, and the temperatures for optimum k values and thermal inactivation were obtained. Once the C degradation rate constants and their T dependence equations were available, it was possible to simulate the evolution of C degradation in an actual pilot scale rotary drum composting process under varying temperatures and using the same biowaste mixtures. The comparison between the theoretical profiles and the experimental data showed that the thermophilic stage could be accurately simulated; however, errors and lower levels of model accuracy occurred when the maturation stage was simulated. The simulation was valid for all of the viewed biowaste mixtures. The 2C and 3C simulation profiles were quite similar in all cases for much of the process duration; the differences between the profiles only occurred after the end of the thermophilic stage. It was concluded that the 2C model would be only valid for shorter experimental periods, until the readily biodegradable carbon fraction was removed, while the 3C model reproduced the subsequent degradation in the maturation stage more closely.

Authors+Show Affiliations

Chemical Engineering Department, Institute for Chemical and Environmental Technology (ITQUIMA), University of Castilla-La Mancha, Avenida Camilo José Cela S/N, 13071 Ciudad Real, Spain. jose.villasenor@uclm.esNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Validation Study

Language

eng

PubMed ID

22595131

Citation

Villaseñor, J, et al. "Simulation of Carbon Degradation in a Rotary Drum Pilot Scale Composting Process." Journal of Environmental Management, vol. 108, 2012, pp. 1-7.
Villaseñor J, Rodríguez Mayor L, Rodríguez Romero L, et al. Simulation of carbon degradation in a rotary drum pilot scale composting process. J Environ Manage. 2012;108:1-7.
Villaseñor, J., Rodríguez Mayor, L., Rodríguez Romero, L., & Fernández, F. J. (2012). Simulation of carbon degradation in a rotary drum pilot scale composting process. Journal of Environmental Management, 108, 1-7. https://doi.org/10.1016/j.jenvman.2012.04.030
Villaseñor J, et al. Simulation of Carbon Degradation in a Rotary Drum Pilot Scale Composting Process. J Environ Manage. 2012 Oct 15;108:1-7. PubMed PMID: 22595131.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Simulation of carbon degradation in a rotary drum pilot scale composting process. AU - Villaseñor,J, AU - Rodríguez Mayor,L, AU - Rodríguez Romero,L, AU - Fernández,F J, Y1 - 2012/05/16/ PY - 2012/01/11/received PY - 2012/04/12/revised PY - 2012/04/23/accepted PY - 2012/5/19/entrez PY - 2012/5/19/pubmed PY - 2012/12/10/medline SP - 1 EP - 7 JF - Journal of environmental management JO - J. Environ. Manage. VL - 108 N2 - This paper studies the simulation of carbon degradation in pilot scale solid waste composting processes using first-order kinetic models previously calibrated by laboratory experiments at different temperatures. Different solid biowastes (olive mill waste, winery waste, sewage sludge and reed biomass) were used. Three mixtures were prepared from combinations of the materials listed above, and they were used in both the laboratory kinetic experiments and the pilot scale composting experiments. Lab experiments were conducted in small reactors with temperature (T) control and forced aeration of the solid mixture. Each biowaste mixture was treated at four different temperatures, 25, 40, 50 and 60 °C, with controlled moisture; the carbon (C) concentration of the samples was measured weekly. Two different kinetic models were used to fit the carbon mineralisation curves: the 2C model, which considers two organic fractions (biodegradable and non-biodegradable), and the 3C model, which considers three fractions (easily biodegradable, slowly biodegradable and non-biodegradable). In both cases, the kinetic rate constants were calculated by mathematical fitting. The influence of temperature on the rate constants was also studied for both models using a T-dependent equation. The theoretical k(T) curves showed classical shapes, and the temperatures for optimum k values and thermal inactivation were obtained. Once the C degradation rate constants and their T dependence equations were available, it was possible to simulate the evolution of C degradation in an actual pilot scale rotary drum composting process under varying temperatures and using the same biowaste mixtures. The comparison between the theoretical profiles and the experimental data showed that the thermophilic stage could be accurately simulated; however, errors and lower levels of model accuracy occurred when the maturation stage was simulated. The simulation was valid for all of the viewed biowaste mixtures. The 2C and 3C simulation profiles were quite similar in all cases for much of the process duration; the differences between the profiles only occurred after the end of the thermophilic stage. It was concluded that the 2C model would be only valid for shorter experimental periods, until the readily biodegradable carbon fraction was removed, while the 3C model reproduced the subsequent degradation in the maturation stage more closely. SN - 1095-8630 UR - https://www.unboundmedicine.com/medline/citation/22595131/Simulation_of_carbon_degradation_in_a_rotary_drum_pilot_scale_composting_process_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0301-4797(12)00227-7 DB - PRIME DP - Unbound Medicine ER -