Economic and Feasibility Analysis of Process Selection and Resource Allocation in Decentralized Wastewater Treatment for Developing Regions

Highly developed urbanized areas rely on centralized wastewater treatment and an elaborately planned sewerage system. For developing regions and remote areas installing a centralized plant and achieving maximum coverage with a sewerage system connecting to that plant implies high capital cost. In such cases, it is feasible for these regions to opt for a multiple decentralized treatment plants. Septic tanks and wetlands are the current scenario of onsite and decentralized systems. These options have a large area requirement (Brissaud, 2007). More “sophisticated” options like the activated sludge process have large energy consumption. This paper overviews various existing decentralized treatment systems all over the world to form deductions on the footprint and energy consumption of these systems. It also theoretically compares the footprint and energy requirement for conventional biological unit processes based on their design for three flow rates. Overall, this study suggests a methodology for the initial process selection during the planning of a decentralized wastewater system.