Effective Carbon Dioxide Mitigation and Improvement of Compost Nutrients with the Use of Composts’ Biochar

Abstract

Composting is a process that emits environmentally harmful gases: CO2, CO, H2S, and NH3, negatively affecting the quality of mature compost. The addition of biochar to the compost can significantly reduce emissions. For effective CO2 removal, high doses of biochar (up to 20%) are often recommended. Nevertheless, as the production efficiency of biochar is low—up to 90% mass loss—there is a need for research into the effectiveness of lower doses. In this study, laboratory experiments were conducted to observe the gaseous emissions during the first 10 days of composting with biochars obtained from mature composts. Biochars were produced at 550, 600, and 650 °C, and tested with different doses of 0, 3, 6, 9, 12, and 15% per dry matter (d.m.) in composting mixtures, at three incubation temperatures (50, 60, and 70 °C). CO2, CO, H2S, and NH3 emissions were measured daily. The results showed that the biochars effectively mitigate CO2 emissions during the intensive phase of composting. Even 3–6% d.m. of compost biochars can reduce up to 50% of the total measured gas emissions (the best treatment was B650 at 60 °C) and significantly increase the content of macronutrients. This study confirmed that even low doses of compost biochars have the potential for enhancing the composting process and improving the quality of the material quality.

Utilization of CO2-captured poly(allylamine) as a polymer surfactant for nanoarchitecture production in a closed CO2 cycle

“…To reduce atmospheric CO 2 , numerous efforts employing various innovative methods have been made, including the reduction of CO 2 through photochemical, 17–19 electrochemical 20–23 and biological approaches 24 into valuable compounds such as formic acid, formaldehyde, methanol and hydrocarbons; the co-reduction with nitrate to produce urea; 25 the incorporation of CO 2 into polymer main chains via copolymerization; 26–28 and composting with biomass. 29,30 These methods offer new avenues for fixing CO 2 and producing materials composed of it. However, these methods have not yet been effective enough to significantly reduce atmospheric CO 2 concentrations.…”