Influence of the composition of the initial mixtures on the chemical composition, physicochemical properties and humic-like substances content of composts

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Maria Elisabete F. Silva (Author) Other; Luís Teixeira de Lemos (Author) Other; Olga C. Nunes (Author) FEUP; Ana Cristina Cunha Queda (Author) Other

Journal

Title: Waste Management

Vol. 34 No. 1

Pages: 21-27

ISSN: 0956-053X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 32 Citations

Scopus - 35 Citations

Scientific classification

FOS: Engineering and technology > Environmental engineering

Associated Projects

UI0511 - PROJECTO ESTRATÉGICO - UI 511 - 2013-2014

Other information

Authenticus ID: P-008-P75

DOI: 10.1016/j.wasman.2013.09.011

Abstract (EN): The influence of the proportion of C- and N-rich raw materials (initial C/N ratio) and bulking agent on the chemical functional groups composition, humic-like substances (HS-like) content and physicochemical properties of composts was assessed. To achieve these goals, seven initial mixtures (BA1-6 and C1) of dog food (N-rich raw material) were composted with wheat flour (C-rich raw material). Composts were analyzed in terms of chemical functional groups, physicochemical, maturity and stability parameters. The C-rich raw material favored the formation of oxidized organic matter (OM) during the composting process, as suggested by the variation of the ratios of the peaks intensity of FT-IR spectra, corresponding to a decrease of the polysaccharides and an increase of aromatic and carboxyl-containing compounds. However, although with high proportion of C-rich raw material, mixtures with low initial C/N seems to have favored the accumulation of partially oxidized OM, which may have contributed to high electrical conductivity values in the final composts. Therefore, although favoring the partial transformation of OM into stabilized HS-like, initial mixtures with high proportion of C-rich raw material but with low initial C/N led to unstable composts. On the other hand, as long as a high percentage of bulking agent was used to promote the structure of biomass and consequently improve of the aeration conditions, low initial C/N was not a limiting factor of OM oxidation into extractable stabilized humic-like acids.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7