Waste to Wealth: Value Recovery from Bakery Wastes

Abstract

Compost is considered a soil-amending product that can be used for soil improvement and to increase the productivity of organic vegetable crops. Composting can be an alternative solution for solid waste management. In this research, the efficacy of various bakery wastes and bulking agents, such as cow dung, to produce compost were studied. The bin composting method was applied in this research. Commercial effective microorganism was used to study its effectiveness in composting bakery waste compared to common ways of composting. Six compost trials were designed by using different ratios of feedstocks such as creamy and non-creamy bakery waste, paper boxes, eggshells, cow dung, dry leaves, and effective microorganism (EM). For the assessment of the maturity, stability, and quality of the compost, various physical and chemical parameters were routinely monitored, including temperature, pH, electrical conductivity (EC), moisture content, water holding capacity (WHC), phytotoxicity and color intensity of water extract, total organic carbon (TOC), total nitrogen (N), phosphorus (P), potassium (K), and C/N ratio. All six compost trials reached the four important phases of temperature, which are the mesophilic phase, thermophilic phase, second mesophilic phase (cooling phase), and maturation phase. The pH, EC, N, P, and K of every compost trial complied with standard compost requirements. Phytotoxicity study proved that all the compost trials were phytotoxic-free when tested with Phaseolus vulgaris (green bean). The water holding capacity of all six trials ranged from 2.18 to 4.30 g water/g dry material. Various compost trials achieved C/N ratios ranging from 12.01 to 14.48, which is considered within the satisfactory limit. The results showed that bakery waste can be turned into compost, with its quality complying with standard requirement.