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

Abstract

A b s t r a c t. The study addresses the problem of assessment of the chemical properties of compost produced on the basis of organic fraction of municipal waste, including the quantity and quality of organic matter. Six composts originating from central-eastern Poland were included in the research. The following analyses were performed: pH; salinity; content of C, N, P, K and heavy metals, fractional composition of organic matter (after decalcification, bitumens, fulvic acids, humic acids and post-extraction residue) and properties of humic acids (elemental composition and spectrophotometric properties). The analysed composts were characterised by a similar chemical nature. They were considered to be chemically and biologically silised. They were characterised 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 their use as a fertiliser. The contribution of carbon of humic substances (separated by 0.1 M NaOH) ranged from 23.3 to 31.2%. Among humic substances the most humic acids prevailed, 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.K e y w o r d s: compost, humic substances, humic acids

Organic Matter Properties of Spent Button Mushroom Substrate in the Context of Soil Organic Matter Reproduction

“…Carbon and nitrogen contents recorded in the present study confirm claims of other researchers that the material displays a marked potential when applied to enrich soils in biogenic elements [3,4]. Nitrogen contents in the tested substrates were similar to those in cattle manure [2] and about twice as high as the contents in municipal waste-based composts [24,31].…”

“…Organic matter content in the tested SMSs (378-519 g kg −1 ) was higher than the values recorded in Polish composts produced from municipal waste whose organic matter content averaged 282 (n = 6) g kg −1 [24]. The obtained results confirm a marked role of SMS in the enrichment of the fertilised soils with organic matter.…”

“…The experimental material had varied dry matter contents which averaged 35% (Table 2). It is higher compared with cattle or swine manure [30] but lower than values determined in composts produced from municipal waste [24,31]. Data on SMS density and reserves on growing chamber shelves revealed a slight variation of these characteristics in the tested wastes obtained from eight growing chambers.…”

“…Sequential fractioning of carbon compounds was conducted using the Schnitzer method [24,25] (Scheme 1). The name, symbol, and procedure of obtaining carbon fractions are shown in Table 1.…”

The Effect of Waste Materials on the Content of Some Macroelements in Test Plants

“…Thus, they need to be processed, e.g. by adding mineral or organic substances [Belmonte 2006, Jackson andMiller 2000] or composting [Becher et al 2018]. Such substances include incineration ashes which, when mixed with sewage sludge, may become a material with beneficial physico-chemical parameters.…”