Study of the effect of a bulking agent on the biodrying of municipal solid waste

The characteristics of municipal solid waste in Indonesia tend to be wet and have a low calorific value. Therefore, a pre-treatment process is needed to dry the municipal solid waste before converting it into RDF. Biodrying is one of the solid waste drying methods that can be used for this purpose. This study aims to determine the effect of variations in bulking agents on the biodrying performance of municipal solid waste and to compare the resulting product with RDF standards. Reactor 1 consists of 100% organic waste without a bulking agent. Reactors 2, 3, and 4 contain organic waste mixed with straw, wood shavings, and rice husks, respectively, as bulking agents. The experiment lasted for 30 days. Measurements were taken for solid waste mass, temperature, moisture content, calorific value, proximate analysis (including volatile solids, fixed carbon, and ash content), and ultimate analysis. Statistical analysis of the test parameters showed that the addition of bulking agents significantly affected the moisture content and fixed carbon levels. A comparison between the biodrying results and RDF standards from several references shows that the biodried waste only meets RDF requirements for volatile content, chlorine, and sulfur. Among the variations tested, the organic waste mixed with straw (Reactor 2) yielded the most optimal results compared to other variations, with a moisture content of 54.33% (wet basis) and a calorific value of 5.4 MJ/kg.