Abstract
The current wide diffusion of bio-degradable plastic made up by starch-based polymeric composite has focused the attention on the allocation of bio-polymers for the direct recycling in composting processes. Actually, the acknowledged current methods to estimate the bio-degradability are mainly based on laboratory tests and measurements under controlled conditions, while scarce information are available on the effective transformation of bio-film derivatives in real composting facilities. The aim of this paper was to determine at molecular level the decomposition of specific starch-based thermoplastic mulching film for horticultural crops, in a real on-farm composting system for the attainment of mature compost for agricultural application. The initial and final molecular composition of both bulk biomasses and bio-plastic composite were evaluated through 13C solid-state CPMAS-NMR spectroscopy and off-line thermochemolysis—gas chromatography–mass spectrometry. The effective decomposition of the bio-polymer was shown by mono-dimensional and pseudo-2D NMR experiments that revealed the alteration of the intermolecular linkages among the monomeric constituents, while the thermochemolysis confirmed the complete decomposition of starch components. Concomitantly, the molecular characterization of bulk compost indicated the typical selective preservation of hydrophobic components currently found in aerobic composting processes, with a significant increase (+50 %) for the yields of aromatic lignin derivatives and recalcitrant aliphatic compounds. In addition to the classical testing methodologies, the detailed analytical investigation represents a powerful methodology to elucidate the molecular composition and modification of plastic bio-polymers thereby providing a valuable contribution to further promote the composting process as viable way to recycle the biodegradable polymeric materials.
Highlights
The current wide diffusion of bio-degradable plastic made up by starch-based polymeric composite has focused the attention on the allocation of bio-polymers for the direct recycling in composting processes
The elemental analysis revealed a slight increase for both total organic carbon (TOC) content and C/N ratio, while a significative decrease was observed in the H/C ratio (Table 1)
The effective degradation of the starch-based biopolymer used to make mulching films was successfully proved within an on-farm composting system
Summary
The current wide diffusion of bio-degradable plastic made up by starch-based polymeric composite has focused the attention on the allocation of bio-polymers for the direct recycling in composting processes. The acknowledged current methods to estimate the bio-degradability are mainly based on laboratory tests and measurements under controlled conditions, while scarce information are available on the effective transformation of bio-film derivatives in real composting facilities. Much of the plastic products for domestic, industrial, and agricultural applications have been progressively replaced by more environmentally compatible bio-decomposable polymers [1, 2]. The wide diffusion of bio-plastics as bag container for the recyclable organic fraction of municipal solid waste, and the more recent application as bio-films for mulching treatment of horticultural crops, has focused the attention on the possible allocation of bio-degradable polymers for the direct recycling in composting processes [7]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Chemical and Biological Technologies in Agriculture
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.