IMPROVING THE CIRCULARITY OF BIODEGRADABLE BIOPLASTICS BY PRODUCING BIOGAS: A FULL-SCALE ASSESSMENT
type: CreativeWork
description: Abstract Polylactic acid (PLA) is one of the commonly used bioplastics, promoted as a sustainable alternative to conventional plastics. Their anaerobic co-digestion with the organic fractions of municipal solid waste (OFMSW) is a promising end-of-life scenario, as it reduces pre-treatment and increases process efficiency and biogas production. However, PLA shows poor biodegradability under anaerobic digestion (AD) conditions, requiring long retention times (HRTs) compared to industrial OFMSW plants’ HRTs. This limits their integration into biogas plants and their potential for integration in the circular bioeconomy. To overcome HRT's limitations of PLA, Microbial acclimation has emerged as an eco-friendly strategy to enhance bioplastic degradation; however, its potential to degrade PLA in co-digestion with OFMSW remains unexplored. Moreover, PLA commercial products are present in the waste stream with varying thicknesses and shapes due to their diverse applications; however, the impact of product thickness on the anaerobic degradation performance of these products, when the same total surface area is maintained, is poorly understood. In this regard, this thesis addresses these gaps by investigating, in the first study, microbial acclimation as a strategy to enhance PLA biodegradability and biogas production under mono- and co-digestion, as well as the microbial communities enriched during PLA acclimation in different settings. Moreover, in the second study, the role of product thickness on their anaerobic degradation performance was studied. The first study results demonstrate that microbial acclimation significantly improves PLA biogas yield in mono-digestion by up to 152% (831 ± 11 NL kgVS−1) and biogas production rate from 27 to 47 NL kgVS−1 d−1, with a reduction in the lag phase by 5 days. This enhancement was linked to the enrichment of the PLA-degrading bacteria Tepidanaerobacter. While in PLA + OFMSW co-digestion, biogas production increased by 69% (827 ± 69 …
abstract: Abstract Polylactic acid (PLA) is one of the commonly used bioplastics, promoted as a sustainable alternative to conventional plastics. Their anaerobic co-digestion with the organic fractions of municipal solid waste (OFMSW) is a promising end-of-life scenario, as it reduces pre-treatment and increases process efficiency and biogas production. However, PLA shows poor biodegradability under anaerobic digestion (AD) conditions, requiring long retention times (HRTs) compared to industrial OFMSW plants’ HRTs. This limits their integration into biogas plants and their potential for integration in the circular bioeconomy. To overcome HRT's limitations of PLA, Microbial acclimation has emerged as an eco-friendly strategy to enhance bioplastic degradation; however, its potential to degrade PLA in co-digestion with OFMSW remains unexplored. Moreover, PLA commercial products are present in the waste stream with varying thicknesses and shapes due to their diverse applications; however, the impact of product thickness on the anaerobic degradation performance of these products, when the same total surface area is maintained, is poorly understood. In this regard, this thesis addresses these gaps by investigating, in the first study, microbial acclimation as a strategy to enhance PLA biodegradability and biogas production under mono- and co-digestion, as well as the microbial communities enriched during PLA acclimation in different settings. Moreover, in the second study, the role of product thickness on their anaerobic degradation performance was studied. The first study results demonstrate that microbial acclimation significantly improves PLA biogas yield in mono-digestion by up to 152% (831 ± 11 NL kgVS−1) and biogas production rate from 27 to 47 NL kgVS−1 d−1, with a reduction in the lag phase by 5 days. This enhancement was linked to the enrichment of the PLA-degrading bacteria Tepidanaerobacter. While in PLA + OFMSW co-digestion, biogas production increased by 69% (827 ± 69 …
author: ELBOGHDADY, HAGER GALAL ELSAYED
language: eng
keywords: Settore AGRI-06/B - Chimica agraria
date published: 2025-12-17
date modified: 2026-07-27T20:19:10Z
provider: Università degli Studi di Milano
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Università degli Studi di Milano

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property ID: Handle
value: https://hdl.handle.net/2434/1200417