Chemical composition of compost from municipal waste in the context of use as fertiliser

Abstract

In the study problem of chemical properties assessment, including quantity and quality of organic matter, compost produced on the basis of organic fraction of municipal waste was undertaken. Six composts originating from central-eastern Poland were included in the research. The following analyzes were performed: pH; salinity; content of C, N, P, K and heavy metals, fractional composition of organic matter (after decalcation, bitumens, fulvic acids, humic acids and post-extraction residue) and properties of humic acids (elemental composition and spectrophotometric properties). The analyzed composts were characterized by a similar chemical nature. They were considered to be chemically and biologically stabilized. They are characterized by a significant potential for soil enrichment in soil humus and biogenic elements. The content of heavy metals in the tested composts did not constitute a barrier to fertilizer use. The contribution of carbon of humic substances (separated by 0.1 M NaOH) ranged from 23.3% to 31.2%. Among humic substances prevailed the most stable humic acids, with the ratio of humic to fulvic carbon from 2.07 to 3.03. The elemental composition of humic acids of the tested composts was similar to those occurring in humus horizons of intensively used arable soils. Spectrophotometric parameters indicated a low degree of their humification.

Keywords

• compost
• humic acids
• humic substances