Simplex-centroid mixture for Municipal Solid Waste Treatment Optimisation

A model describing the relationship between waste treatment method and greenhouse gases (GHGs) emission is proposed in this study. Three constituents, i.e., composting, reuse and recycle are analysed using extreme vertices mixture design to determine the model. Mixture design enables identifying of optimum combination of each constituent producing the lowest GHGs emission. Emission of greenhouse gases (GHGs) as a regress and were analysed how they change when the amount of waste changes. The result showed that there are four possible models. One best model is chosen for its least standard deviation, lowest P-value and the highest adjusted R2 which is 5.764 x 10-3, less than 0.005, and 0.9908 respectively. The model describes that lowest GHGs emission can be achieved by maximizing plastic recycle (into flakes), limiting composting and increasing paper, glass and metal reuse. Composting, reuse and recycle is proportional to the GHGs emission individually, while combination of two constituents is inversely proportional to GHGs emission. The lowest GHGs may be emitted from the plant is 0.107 Gg CO2 equivalent/year with the composition of constituents as followed: 14 % composting, 50 % reuse, and 26 % recycle equals to 1.3 m3, 4.7 m3 and 2.1 m3 waste from each method.