2024 Volume 80 Issue 25 Article ID: 24-25036
The objective of this study was to determine a centralized (collective treatment) or decentralized (individual treatment) domestic wastewater treatment system based on a multidimensional evaluation. Cost per household, greenhouse gas (GHG) emissions, digester gas potential, and phosphorus recovery potential were formulated as a function of household density for collective and individual treatment systems, respectively. The results suggested that the household density at which these index values are in equilibrium between centralized and decentralized systems was lower than 40 persons per hectare, which has been the profit bifurcation point. The allocation of collective and individual treatments was determined to minimize the sum of the weights of the four indicators using the simulated annealing for a hypothetical residential area with an appropriate spatial distribution of houses. The best mix of centralized and decentralized treatment that can minimize costs and GHG emissions was clarified. The results also suggested that infrastructure hybridization with food waste collection system and novel elemental technologies are necessary to achieve energy independence for a wastewater treatment plant.
