Optimizing Organic Waste Transformation: Advanced Aeration Strategies for Superior Compost Quality

Composting is a biodegradation process where oxygen availability controls microbial activity, organic matter transformation, and compost quality. While many aeration systems have been studied, direct comparisons under identical conditions. Widely investigated, direct comparisons among multiple aeration configurations under, especially for heterogeneous waste mixtures, are still limited. This study examined seven aeration strategies (manual turning, substrate grinding, perforated vertical tubes, lignocellulosic structuring agents, a bottom aeration grid, perforated container walls, and a combined method integrating turning, bottom aeration, and distributed wood chips) to determine their effects on compost stability. A mixed substrate (sewage sludge, cattle manure, wheat straw, potato peels, legume shells, and wood shavings) was composted in twenty-one units (seven treatments × three biological replicates) over ten weeks. Temperature and pH were recorded every three days, while organic matter, total carbon, total nitrogen, C:N ratio, electrical conductivity, phosphorus, potassium, phytotoxicity using germination tests, and self-heating were assessed in the final compost. All treatments achieved thermophilic conditions (55–64°C) and showed pH shifts from initial acidic values (5.4–6.0) to near-neutral or alkaline levels (7.0–7.8), confirming stabilization. Aeration strategy significantly influenced decomposition pathways, nutrient retention, and biological maturity. Vertical perforated tubes, combined aeration, and manual turning produced composts with C:N ratios within 10–20, nitrogen conservation, reduced phytotoxicity, and germination performance (80–95% at 50% extract concentration). Statistical analysis using ANOVA followed by Tukey HSD confirmed aeration as a key factor. Moderate, well-planned aeration methods improved compost stability and maturity more than high-intensity aeration.