Rigid bioplastics shape the microbial communities involved in the treatment of the organic fraction of municipal solid waste.

While bioplastics are gaining wide interest in replacing conventional plastics, it is necessary to understand whether the treatment of the organic fraction of municipal solid waste (OFMSW) as an end-of-life option is compatible with their biodegradation and their possible role in shaping the microbial communities involved in the processes. In the present work, we assessed the microbiological impact of rigid polylactic acid (PLA) and starch-based bioplastics (SBB) spoons on the thermophilic anaerobic digestion and the aerobic composting of OFMSW under real plant conditions. In order to thoroughly evaluate the effect of PLA and SBB on the bacterial, archaeal, and fungal communities during the process, high-throughput sequencing (HTS) technology was carried out.

Anaerobic digestion and aerobic composting of rigid biopolymers in bio-waste treatment: fate and effects on the final compost.

Bioplastics may be collected in the bio-waste treatment, which is often composed of anaerobic digestion and subsequent aerobic composting of the digestates. The aim of this study was to evaluate the degradability of polylactic acid (PLA) and starch-based bioplastics (SBB) spoons under industrial conditions. Biomethane potential (BMP) was measured and biogas production was monitored, while the quality of composts was assessed by phytotoxicity and ecotoxicity tests.

Determination of volatile fatty acids in digestate by solvent extraction with dimethyl carbonate and gas chromatography-mass spectrometry.

Volatile fatty acids (VFAs) are among the most important parameters in process monitoring of anaerobic digestion plants for biogas production. The concentration of single VFA species is typically determined by direct injection of the acidified aqueous phase of digestate samples into GC-FID. Analysis of dimethyl carbonate extracts was investigated as an alternative method consisting of a simple and rapid in-vial procedure of acidification and solvent extraction of the sample, followed by centrifugation and GC-MS analysis.

Methodological approach for trace elements supplementation in anaerobic digestion: Experience from full-scale agricultural biogas plants.

Trace metals play a very important role on the performance and stability of agricultural biogas digesters. The purpose of this study was to develop a methodological approach to quickly detect limiting conditions due to Trace Elements (TE) concentration in full-scale biogas plants. The work was based on long-term process monitoring in two full-scale agricultural biogas plants and on the correlation between their performance and TE concentration in the digesters.

Fate of mycotoxins and related fungi in the anaerobic digestion process.

In this study, the possibility to manage maize contaminated with aflatoxins and fumonisins for the production of biogas was considered. This is a priority in the climate change scenario that is expected to increase the occurrence of aflatoxins in maize. The results clearly underline how the anaerobic digestion process used in biogas plants is able to reduce aflatoxin contamination, mainly when highly contaminated maize is used for feeding the biodigestors without affecting the efficiency of methane production.

Monitoring of full-scale hydrodynamic cavitation pretreatment in agricultural biogas plant.

The implementation of hydrodynamic cavitation (HC) pretreatment for enhancing the methane potential from agricultural biomasses was evaluated in a full scale agricultural biogas plant, with molasses and corn meal as a supplementary energy source. HC batch tests were run to investigate the influence on methane production, particle size and viscosity of specific energy input. 470kJ/kgTS was chosen for the full-scale implementation.

Application of a horizontal subsurface flow constructed wetland on treatment of dairy parlor wastewater.

Two horizontal subsurface flow reed beds of 75 m(2) each, treating dairy parlor effluent and domestic sewage (about 6.5 m(3)/day), were set-up to determine the efficiency of this system in reducing the polluting load in an isolated mountain rural settlement.A total suspended solids value of about 0.