Performance and Cost Analysis of Decentralized Wastewater Treatment Plants in Northern India: Case Study

Abstract

In this study, a techno-economic analysis of 16 decentralized wastewater treatment plants (WWTPs) based on various technologies was performed in northern India. Six elements including treatment performance, land use, capital investment, operation and maintenance, cost of treatment, and electricity consumption are discussed in this study. The technologies assessed are extended aeration (EA), moving bed bioreactor (MBBR), sequential bioreactor (SBR), rotating biological contactor (RBC), on-site package (aerobic and/or anaerobic), and membrane bioreactor (MBR). The results indicate that the treatment efficiencies of all cluster-type WWTPs differed significantly from on-site anaerobic package (AnP) types. On the other hand, the treatment efficiencies of on-site aerobic package (AP) systems were reasonably comparable to those of cluster-type plants. The land use for on-site package treatment systems was estimated between .125 and .8 m2 per population equivalent (pe) and higher than for cluster-type WWTPs, which require between .39 and .159 m2/pe. The data collected from this study show that package plant treatment costs are high compared with those of cluster types, ranging from US$.676 to .145 (±1%) and from US$.353 to .1891/m3 (±15−2%), respectively. Cost-benefit analysis (CBA) was undertaken for all the WWTPs and among the considered environmental benefits nitrogen removal contributed to the most. Moreover, the operation of WWTPs was found to be economically viable even without the sale of treated water, except for one AnP plant. For all plants evaluated, specific power consumption (SPC) was found to vary between and 1 kW/m3.