• Food waste composting with amendments stabilized within 75 days. • Poultry manure reached 59 °C, accelerating compost maturation. • Mass loss (43–82%) and C:N drop (4.5–16.9) confirmed decomposition. • Final compost rich in N, P, and K with acceptable pH and EC levels. • Low Pb and Zn; no Salmonella and low E. coli confirmed safety. Composting of food waste represents an effective strategy for organic waste valorization and nutrient recovery. This study evaluated the composting dynamics and final compost quality of food waste amended with cow manure, poultry manure, and cocoa husk biochar under controlled turning conditions. Seven treatments (T1–T6) and a control were composted for 75 days with twice-weekly turning. Composting performance was assessed through temperature evolution, moisture dynamics, pH, electrical conductivity, mass reduction, and pathogen indicators, while compost quality was evaluated based on nutrient composition, C:N ratio, and heavy metal concentrations. All treatments exhibited typical composting temperature profiles, reaching thermophilic conditions within 5–7 days. Peak temperatures ranged from 45 to 59 °C, with poultry manure–amended treatments achieving the highest temperatures, indicating enhanced microbial activity and effective sanitization. Moisture content declined from initial values of 44–68% to 16–25% at maturity due to microbial heat generation and evaporation. Substantial mass reductions (43–82%) indicated efficient organic matter degradation. Final composts exhibited alkaline pH (8.5–10.4), electrical conductivity below 6.5 mS cm –1 , and increased nutrient concentrations, with total nitrogen ranging from 2.35 to 3.87%, phosphorus from 0.55 to 1.37%, and potassium from 4.69 to 5.72%. Final C:N ratios ranged from 4.46 to 16.92, indicating mature compost products. Heavy metal concentrations remained well below regulatory limits, while Salmonella was absent and Escherichia coli levels were below the recommended threshold of 1.0 × 10 3 CFU g –1 for compost intended for agricultural use, consistent with US EPA Class A biosolids standards. Poultry manure amendments enhanced composting efficiency and nutrient enrichment, while cocoa husk biochar contributed to improved compost stability and nutrient retention. These findings demonstrate the potential of combining food waste, livestock manure, and cocoa husk biochar to produce nutrient-rich, hygienically safe compost suitable for sustainable soil fertility management.
Akuaku et al. (Fri,) studied this question.