Efficacy of Modified Biochar on the Food Waste and Livestock Manure Management through In-Vessel Composting Process
Improper Food waste and livestock manure management leads that decomposes in landfills releases huge amount of greenhouse gases(GHG), harmful pathogens, odor and eutrophication; hence, it has public health and environmental concern. In this regard, Composting is most economical and feasible technology for food waste( FW) and swine manure(SM) management. Swine manure (SM) and food waste was mixed with sawdust (SD), then amended with modified biochar in order to obtain the following mixtures (C) SM:FW: SD–Swine manure mixed with sawdust without the addition of modified biochar (control) (1:1:0.5 ; w/w dry basis), (T1) SM:FW:SD + 3% B–swine manure mixed with sawdust (1:1:0.5 ; w/w dry basis) with the addition of 3% of biochar, (T2) SM:FW:SD + 5% B–swine manure mixed with sawdust (1:1:0.5 ; w/w dry basis) with the addition of 5% of biochar, and(T3) SM:FW:SD + 10% B–swine manure mixed with sawdust (1:1:0.5 ; w/w dry basis) with the addition of 10% of biochar. The initial waste mixtures moisture content adjusted to 65% . The temperature was monitored every 12 hrs , while the gaseous emission( NH3, CO2, ,CH4, N2O) checked every 24 hrs. The aeration provided at a flow rate of 0.5 L/min/kg (dry weight) through an aerator pump. The co- composting mass inside the reactor taken out and mixed thoroughly and samplings on day 3, 7, 10, 14, 17, 21, 28, 35 and 40 for the analysis of physicochemical properties, phytotoxic analysis, microbial activities. The results showed that, compared to the control( without biochar), modified biochar amended compost mixtures had significantly reduced (p ≤ 0.05) C:N ratio, NH3 emission, bulk density, organic matter(OM) and pathogenic microorganisms at the end of 50 days. On the other hand, modified biochar amendment mixtures had increased total porosity(TP), water holding capacity(WHC), rapid thermophilic temperature, and nitrate nitrogen. However, with the most prominent effects in terms of nutrient quality and degradation rate of compost mixtures, the amendment of 10% biochar is recommended for foodwaste and livestock manure management through the in -vessel composting process.
Keywords - Food Waste, Livestock Manure, Biochar, Greenhouse Gases(GHG), In-vessel Composting