Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions

The global production of brewers’ spent grains (BSG) is 37 million tons yearly. Composting represents an eco-friendly method to manage and valorize organic by-products in a circular economy model. This project aims to compare two BSG bin-composting mixtures (BSG and wheat straw with pig slurry solid...

Full description

Saved in:
Bibliographic Details
Main Authors: Davide Assandri, Ginevra Giacomello, Angela Bianco, Giacomo Zara, Marilena Budroni, Niccolò Pampuro
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Agronomy
Subjects:
Online Access:https://www.mdpi.com/2073-4395/15/4/771
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850156107765383168
author Davide Assandri
Ginevra Giacomello
Angela Bianco
Giacomo Zara
Marilena Budroni
Niccolò Pampuro
author_facet Davide Assandri
Ginevra Giacomello
Angela Bianco
Giacomo Zara
Marilena Budroni
Niccolò Pampuro
author_sort Davide Assandri
collection DOAJ
description The global production of brewers’ spent grains (BSG) is 37 million tons yearly. Composting represents an eco-friendly method to manage and valorize organic by-products in a circular economy model. This project aims to compare two BSG bin-composting mixtures (BSG and wheat straw with pig slurry solid fraction, MIX1, or sheep manure, MIX2) and approaches (manual turning, MT, and static composting, ST). The two mixtures’ physicochemical characteristics and greenhouse gas (GHG) emissions were assessed during the process. The evolution of physicochemical properties is reported in detail. Headspace samples of GHG emissions were collected and analyzed with gas chromatography coupled with specific detectors. Carbon dioxide (CO<sub>2</sub>) emissions were 34.3 ± 0.03 and 31.0 ± 0.06 g C kg<sup>−1</sup> fresh matter (FM) for MIX1-MT and MIX2-MT, and 28.8 ± 0.01 and 31.2 ± 0.02 g Ckg<sup>−1</sup> FM for MIX1-ST and MIX2-ST. Methane emissions were negligible (all conditions < 0.086 ± 0.00 mg C kg<sup>−1</sup> FM). Nitrous oxide (N<sub>2</sub>O) emissions from composting are affected by the substrate, bulking material, pile dimension, and manure. Particularly, the total emissions of N<sub>2</sub>O, estimated as CO<sub>2</sub> equivalents, were 45.8 ± 0.2 and 63.0 ± 0.4 g CO<sub>2</sub> eq kg<sup>−1</sup> FM for MIX1-MT and MIX1-ST, respectively. In both composting approaches, MIX2 showed a low CO<sub>2</sub> equivalent (1.8 ± 0.02 and 9.9 ± 0.05 g CO<sub>2</sub> eq kg<sup>−1</sup> FM for MT and ST), likely due to incomplete decomposition. The bin-composting process represents a solution for recycling and reusing organic waste and livestock manure in small to medium-sized breweries. The solid fraction of the pig slurry resulted in the most suitable manure.
format Article
id doaj-art-47d9d412563a42f4af49fea65a7c17fb
institution OA Journals
issn 2073-4395
language English
publishDate 2025-03-01
publisher MDPI AG
record_format Article
series Agronomy
spelling doaj-art-47d9d412563a42f4af49fea65a7c17fb2025-08-20T02:24:41ZengMDPI AGAgronomy2073-43952025-03-0115477110.3390/agronomy15040771Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas EmissionsDavide Assandri0Ginevra Giacomello1Angela Bianco2Giacomo Zara3Marilena Budroni4Niccolò Pampuro5Institute of Sciences and Technologies for Sustainable Energy and Mobility (STEMS), National Research Council of Italy (CNR), Strada delle Cacce 73, 10135 Turin, ItalyInstitute of Sciences and Technologies for Sustainable Energy and Mobility (STEMS), National Research Council of Italy (CNR), Strada delle Cacce 73, 10135 Turin, ItalyDepartment of Agricultural Sciences of University of Sassari, Viale Italia 39/a, 07100 Sassari, ItalyDepartment of Agricultural Sciences of University of Sassari, Viale Italia 39/a, 07100 Sassari, ItalyDepartment of Agricultural Sciences of University of Sassari, Viale Italia 39/a, 07100 Sassari, ItalyInstitute of Sciences and Technologies for Sustainable Energy and Mobility (STEMS), National Research Council of Italy (CNR), Strada delle Cacce 73, 10135 Turin, ItalyThe global production of brewers’ spent grains (BSG) is 37 million tons yearly. Composting represents an eco-friendly method to manage and valorize organic by-products in a circular economy model. This project aims to compare two BSG bin-composting mixtures (BSG and wheat straw with pig slurry solid fraction, MIX1, or sheep manure, MIX2) and approaches (manual turning, MT, and static composting, ST). The two mixtures’ physicochemical characteristics and greenhouse gas (GHG) emissions were assessed during the process. The evolution of physicochemical properties is reported in detail. Headspace samples of GHG emissions were collected and analyzed with gas chromatography coupled with specific detectors. Carbon dioxide (CO<sub>2</sub>) emissions were 34.3 ± 0.03 and 31.0 ± 0.06 g C kg<sup>−1</sup> fresh matter (FM) for MIX1-MT and MIX2-MT, and 28.8 ± 0.01 and 31.2 ± 0.02 g Ckg<sup>−1</sup> FM for MIX1-ST and MIX2-ST. Methane emissions were negligible (all conditions < 0.086 ± 0.00 mg C kg<sup>−1</sup> FM). Nitrous oxide (N<sub>2</sub>O) emissions from composting are affected by the substrate, bulking material, pile dimension, and manure. Particularly, the total emissions of N<sub>2</sub>O, estimated as CO<sub>2</sub> equivalents, were 45.8 ± 0.2 and 63.0 ± 0.4 g CO<sub>2</sub> eq kg<sup>−1</sup> FM for MIX1-MT and MIX1-ST, respectively. In both composting approaches, MIX2 showed a low CO<sub>2</sub> equivalent (1.8 ± 0.02 and 9.9 ± 0.05 g CO<sub>2</sub> eq kg<sup>−1</sup> FM for MT and ST), likely due to incomplete decomposition. The bin-composting process represents a solution for recycling and reusing organic waste and livestock manure in small to medium-sized breweries. The solid fraction of the pig slurry resulted in the most suitable manure.https://www.mdpi.com/2073-4395/15/4/771carbon dioxidemethanenitrous oxidecircular economyaerobic stabilizationagro-industry by-product
spellingShingle Davide Assandri
Ginevra Giacomello
Angela Bianco
Giacomo Zara
Marilena Budroni
Niccolò Pampuro
Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions
Agronomy
carbon dioxide
methane
nitrous oxide
circular economy
aerobic stabilization
agro-industry by-product
title Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions
title_full Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions
title_fullStr Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions
title_full_unstemmed Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions
title_short Environmental Sustainability of Brewers’ Spent Grains Composting: Effect of Turning Strategies and Mixtures Composition on Greenhouse Gas Emissions
title_sort environmental sustainability of brewers spent grains composting effect of turning strategies and mixtures composition on greenhouse gas emissions
topic carbon dioxide
methane
nitrous oxide
circular economy
aerobic stabilization
agro-industry by-product
url https://www.mdpi.com/2073-4395/15/4/771
work_keys_str_mv AT davideassandri environmentalsustainabilityofbrewersspentgrainscompostingeffectofturningstrategiesandmixturescompositionongreenhousegasemissions
AT ginevragiacomello environmentalsustainabilityofbrewersspentgrainscompostingeffectofturningstrategiesandmixturescompositionongreenhousegasemissions
AT angelabianco environmentalsustainabilityofbrewersspentgrainscompostingeffectofturningstrategiesandmixturescompositionongreenhousegasemissions
AT giacomozara environmentalsustainabilityofbrewersspentgrainscompostingeffectofturningstrategiesandmixturescompositionongreenhousegasemissions
AT marilenabudroni environmentalsustainabilityofbrewersspentgrainscompostingeffectofturningstrategiesandmixturescompositionongreenhousegasemissions
AT niccolopampuro environmentalsustainabilityofbrewersspentgrainscompostingeffectofturningstrategiesandmixturescompositionongreenhousegasemissions