The optimization of biocomposting process of kitchen waste

Abstract

In this thesis research, the optimization of the in-vessel biocomposting process of kitchen waste was studied using Design Expert software. Because the kitchen waste have high moisture content, the composting prodess of this type of waste become slow. So, the optimization needs to be done. The Central Composite Design (CCD) was adopted to optimize the biocomposting process of the kitchen waste based on two parameters for carbon to nitrogen (C/N) ratio response. Two main factors which are moisture content and turning time were examined through 13 runs of biocomposting process experiments set by Design Expert software. Based on the results, the main factors (moisture content and turning time) and the higher terms incorporated in the regression model were found to be significant. The high coefficient of determination, R2 which is 0.9412 (94.12 %) indicated that the model obtained from the experiment run will be able to give reasonably good estimate of the response of the biocomposting process in the range studied and only 5.88 % of total variability was not explained by the regressors in the model. The main factors (moisture content and turning time) highly affected the C/N ratio of the compost. The optimum moisture content and turning time are 46.89 % and 4 respectively where the C/N ratio ia at its most minimum at that point which indicated high quality compost.