The article evaluates the effect of small selected doses of biochar addition (0%, 1.5%, 3% and 5%, wet weight) on the composting process of the organic fraction of municipal solid waste (OFMSW) with a low initial C/N ratio under real conditions. The low C/N composting mixtures with addition of biochar at low rates can have a positive effect on the compost quality and on the reduction of N losses in compost. The novelty of this work consists in studying the impact of small biochar doses on the composting process at full-scale. The research was conducted under real conditions in the Brno Central Composting Plant (Czech Republic) receiving food waste, grass, straw, sawdust, mineral waste, paper, wood and sewage sludge for processing. The experimental processing time was 12 weeks. We evaluated changes in carbon (C), nitrogen (N), moisture content (MC), organic matter (OM), respiration activity (AT4), as well as changes in the microbiocenotic composition of microorganisms colonizing the processed waste. OFMSW with the addition of biochar and compost were assessed for the content of heavy metals (HM). It was found out that biochar reduced the compost toxicity. The resulting compost with the addition of biochar exhibited higher moisture content and lower waste density. Biochar had an impact on N retention during composting but it did not change the course or accelerate the composting process. The highest OM loss (62.6%) was observed in the OFMSW with no biochar addition. The abundance of potentially pathogenic microorganisms clearly decreased during the OFMSW composting process with the addition of biochar.

• MeSH
• dřevěné a živočišné uhlí MeSH
• dusík MeSH
• kompostování * MeSH
• půda MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

High-solid anaerobic digestion of the very small particle fraction of mechanically-sorted organic fraction of municipal solid waste (OFMSW) was examined in mesophilic digestion tests in a conventional laboratory (0.013 m3) and a pilot (0.300 m3) reactor. The non-biodegradable and recalcitrant molecules together with the low protein and starch contents of the small-particles of OFMSW limited the methane generation potential of substrate. In the conventional AD system, methane yields remained low at 0.139 m3kgVS-1 due to formation of a non-reacting layer on digestate surface, which restricted utilization of the available in OFMSW digestible organics. The absence of surface solid crust in the pilot unit favoured consumption of a greater proportion of volatile solids of the OFMSW. Dry AD was remarkably stable over the entire period and negligibly effected by the toxic H2S yields. Methane generation (0.167 m3kgVS-1) was increased 1.2-fold compared to the conventional system due to a better mixing of substrate and microorganisms achieved inside the pilot reactor, which led to an increase of the digested volatile organics. Digestate presented low stability and high heavy metal content, both of which restrain its implementation as soil conditioner or fertilizer in agriculture. A secondary co-digestion treatment may be required for the neutralization of digestate.

• MeSH
• anaerobióza MeSH
• bioreaktory MeSH
• laboratoře MeSH
• methan MeSH
• odpadky - odstraňování * MeSH
• tuhý odpad * analýza   MeSH
• Publikační typ
• časopisecké články MeSH