Assessment of Different Technologies for Managing Yard Waste Using Analytic Hierarchy Process

The heterogeneity of solid waste generated by a large population of different socio-economic backgrounds in India makes it difficult to have a universal best treatment option. The present study reports a comprehensive assessment of six different technologies for managing yard waste using analytic hierarchy process (AHP): composting, incineration, landfill, anaerobic digestion, pelletization-gasification, and pelletization-pyrolysis. Four criteria, namely, environmental, economic, technical, and socio-political have been considered for evaluation, with each of these having further sub-criteria. The 4 criteria, 17 sub-criteria, and the 6 alternatives are evaluated using AHP for two different cases: one for calculated weights based on the objective, and other assuming equal weights for each criterion and sub-criterion. The pairwise comparison matrices are formed using data collected from literature and the responses recorded from the questionnaire survey. The results are then synthesized to find the most appropriate process for managing yard waste. For both, case 1 and case 2, pelletization-gasification (PG) was the most promising technology followed by pelletization-pyrolysis (PP). Landfill (LF) and incineration (IN) technologies proved to be the least preferred alternatives for managing yard waste. Finally, a sensitivity analysis is performed to investigate the effect of variation in importance of different criteria on the final rankings of the technology alternatives.