Study of Organic Matter decomposition and stabilization during different waste treatment methods by using Spectroscopy analysis

by Anna Daniela Malerba (Istituto di Cristallografia)

Wednesday 13 Dec 2023, 15:00 → 16:00 Europe/Rome

1/1-1 - Sala Congressi (Area della Ricerca di Bari)

The global annual production of sludge is anticipated to steadily rise, reaching 2 billion tons of dry matter by 2023. Concerns about environmental and economic problems related to waste disposal and depletion of fossil fuels are increasing worldwide, and, consequently, sustainable recycling of biomass is gaining huge popularity.

Defining biomass poses a challenge and the definition has recently evolved to include the concept of sustainable production. Biomass is defined as the biodegradable fraction of products, waste, and residues from organic non-fossil material of biological origin that is readily available in a renewable or recurring sustainable basis and can be also used as a liquid energy source by means of thermal/chemical/biological conversion.

Biological treatments of wastes are capable of degrading organic matter (OM) resulting in a stabilized product which can be added to soil to restore natural OM. Among these treatments, anaerobic digestion (AD) process breaks down OM into simpler chemical components without oxygen input, avoiding oxidation of the matter (under anaerobic conditions), and generates biogas constituted mainly by CH4 (55–80 %) and CO2 (20–45 %) that can be used to produce electricity with lesser greenhouse gases emissions. The final product, the digestate, can be used directly in soil applications or submitted to composting process depending on the degree of digestion attained by the OM.

In this seminar, I will elucidate my contributions – as a chemical analyst – in the study of organic matter evolution during various processes, namely Anaerobic Digestion (AD), Composting (aerobic process) and Pyrolysis (i.e., the thermal process that converts biomasses and organic wastes, into non-condensable gas, liquid fuels and solid biochar residue). The diverse biomasses under investigation encompass municipal solid waste, food waste, sewage sludge and animal manure.

I will also focus on the techniques I employed, including chemical analysis, Fourier Transform Infrared Spectroscopy (FTIR) and fluorescence spectroscopy within an Excitation-Emission Matrix (EEM) characterization.

These analytical techniques prove to be a valuable tool to investigate the consumption of carbohydrates, sugars, proteins, amino acids and fatty acids and an increase of the peak in the aromatic region which indicated OM decomposition and OM stabilization after different processes.

References:

"Anaerobic digestion of municipal solid waste and sewage sludge under mesophilic and thermophilic  conditions. A thermal study in DSC associated to infrared spectroscopy”; Provenzano M. R, Malerba A. D, Buscaroli A, Zannoni D, Senesi, N. JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, 111 (2013) 1861–1870.

"Spectroscopic and thermal characterization of organic matter during the anaerobic digestion and successive composting of pig slurry”. Provenzano M. R, Malerba A. D, Pezzolla D. , Gigliotti G. WASTE MANAGEMENT,  34 (2014) 653–660.

"Hydrophilic and hydrophobic fractions of water-soluble organic matter in digestates obtained from different organic wastes”. Malerba A. D, Klaus Kaiser, Fulvia Tambone, Fabrizio Adani, Alessandro Buscaroli, Provenzano M. R. INTERNATIONAL BIODETERIORATION & BIODEGRADATION,   94 (2014) 73-78.

"Composting posidonia oceanica and sewage sludge: chemical and spectroscopic investigation”.  M.R. Provenzano, V. Carella and A.D. Malerba.  COMPOST  SCIENCE AND UTILIZATION, 23 (2015) 154-163.

"Co-treatment of fruit and vegetable waste in sludge digesters: Chemical and spectroscopic   investigation by fluorescence and Fourier transform infrared spectroscopy”. Provenzano M. R., Cavallo O., Malerba A. D., Di Maria F., Cucina M., Massaccesi L., Gigliotti G. WASTE MANAGEMENT, 50 (2016) 283–289.

"Slow pyrolysis of olive mill solid residues as a sustainable valorization strategy for waste biomass”. Piscitelli, L., Rasse, D.P., Malerba, A.D., Miano, T., Mondelli, D. JOURNAL OF MATERIAL CYCLES AND WASTE MANAGEMENT (2023) 25(3), pp. 1688-1698.