Analysis of compost physical and chemical characteristics by evaluating a bacterial inoculum on MSW

Abstract

Composting is a cost-effective and environmentally friendly way to recycle organic waste. The process of decomposition and the availability of plant nutrients are significantly influenced by soil microorganisms. This study aimed to prepare a suitable microbial inoculum and evaluate its effect on composting heap to reduce the time of waste degradation. Using 16S ribotyping technique, bacteria were isolated and molecularly characterized from soil samples near the composting area. Bacillus cereus and subtilis were identified and used as an inoculum, which resulted in more efficient degradation of organic waste. The prepared bacterial inoculum was compared with a commercial inoculum by optimizing physical and chemical parameters, such as temperature, oxygen, C: N, pH, and moisture content of the composting heap. Monthly readings of these parameters were taken from experimental and control treatments. The results showed that treatment A, where molasses and bacterial inoculum were added, had the highest decomposition rate of organic waste, while treatment D, where no inoculum and molasses were added, had the lowest decomposition rate. The study concluded that the prepared bacterial inoculum with two strains of Bacillus was effective and produced mature compost in 2.5 months, increasing the decomposition efficiency of organic waste. Furthermore, the physical and chemical characteristics of the prepared compost were found to be sustainable. This research highlights the importance of microbial inoculums in composting and demonstrates that the use of a prepared bacterial inoculum can significantly reduce the time of waste degradation while improving the quality of the compost produced.