Monitoring of greenhouse gas emissions and compost quality during olive mill waste co-composting at industrial scale: The effect of N and C sources

Abstract

Olive mill wastes (OMW) management by composting allows to obtain valuable fertilizing products, but also implies significant fluxes of greenhouse gases (GHG). For a proper OMW composting, high C- and N co-substrates are necessary, but little is known concerning their effect on GHG emissions in OMW-industrial scale composting. In this study, different co-composting agents (cattle manure (CM), poultry manure (PM), sheep manure (SM) and pig slurry solid fraction (PSSF) as N sources and olive leaves (OLW) and urban pruning residues (UPR) as bulking agents and C sources) were used for OMW composting at industrial scale. Physico-chemical and chemical properties in the composting samples, and GHG (CO2, CH4 and N2O) fluxes were monitored in 12 industrial-scale windrows. GHG emissions were firstly influenced by N source, with the highest accumulated global warming potential (GWP) associated with PM (512 kg CO2eq pile-1), since PM composts were associated with the greatest N2O (0.33 kg pile-1) and CH4 emissions (15.67 kg pile-1). Meanwhile, PSSF was associated with the highest CO2 emissions (1113 kg pile-1). UPR as a bulking agent facilitated 10 % greater mineralization of the biomass than OLW, however this C-source was not associated with higher GHG emissions. The results showed that while mineralization dynamics may be impacted by C sources, GHG emissions were mainly conditioned by the characteristics of nutrient-heavy feedstocks (PM and SM). Moreover, manures as nitrogen-laden co-substrates had widely differing effects on total GWP, and that of individual gases, but further research is necessary to understand the mechanisms explaining such differences.

Description

Keywords

Bibliographic citation

García-Rández, A., Orden, L., Marks, E. A. N., Andreu-Rodríguez, J., Franco-Luesma, S., Martínez-Sabater, E., Saéz-Tovar, J.A., Pérez-Murcia, M.D., Agullo, E. Bustamante, M.A., Chafer, M., Moral, R. Monitoring of greenhouse gas emissions and compost quality during olive mill waste co-composting at industrial scale: The effect of N and C sources, Waste management, 2024, 193, 33-43
AGROVOC subjects
Gases de efecto invernadero
Compost
Residuos
Olea europaea
Estiércol
Poda
Economía circular

Other field subjects
Compost
Economía circular
Estiércol
Gases de efecto invernadero
Olea europaea
Poda
Residuos

Sponsorship

This work has been developed thanks to the Agrocomposting Collaboration Agreement between the Generalitat Valenciana, through the Department of Agriculture, Rural Development, Climate Emergency and Ecological Transition and the Miguel Hernandez ´ University of Elche. Grant EQC2018-004170-P funded by MCIN/AEI/10.13039/ 501100011033 and by ERDF A way of making Europe. In addition, it was developed in the framework of the research project NEOCOMP (ref. PID2020-113228RB-I00), funded by MCIN/AEI /10.13039/ 501100011033.