Technical efficiency and cost analysis in wastewater treatment processes: A DEA approach

Conditional Order-m Efficiency of Wastewater Treatment Plants: The Role of Environmental Factors

“…Moreover, this is in line with the orientation used in previous studies with the same aim based on data from the same entity [19,21,22,24,27].…”

“…Inputs (€/m 3 ): cost of the energy used, fixed and variable (Energy) [5,17,18,[20][21][22][24][25][26][27], total staffing costs (Staff), including salaries, taxes and social insurance and charges [5,17,18,21,22,[24][25][26][27], and other expenses (Other), which would include the cost of reagents, the maintenance for treatment facilities and infrastructure (such as equipment and machinery, even their replacement), waste management (including sludge) and other concepts (such as offices, laboratories, gardens, etc.) [5,17,18,[20][21][22][23][24][25][26][27].…”

“…The inputs used for the analyses range from purely economic data measured in euros per year, such as operation and maintenance costs, staffing, reagents, or energy costs, to technical data such as the water mass treated expressed as cubic meters. The studies by Hernández-Sancho et al [5,21,22], Hernández-Sancho and Sala-Garrido [26,27], Molinos-Senante et al [17][18][19], Sala-Garrido et al [23][24][25], or Lorenzo-Toja et al [20] include the elimination of contaminants from the treated water as output, calculating this on the basis of initial and final levels of solids in suspension (SS in mg/L), organic material expressed as a chemical demand for oxygen (COD, in mg/L) and nutrients. Apart from this, the last two studies mentioned also take into consideration non-desirable outputs such as sound, odor, and visual impact levels.…”

“…They range from 338 WWTPs, in the case of Hernández-Sancho and Sala-Garrido [26,27], to 45 WWTPs analyzed in the study by Sala-Garrido et al [24], depending on the homogenous subgroup using a specific technology, the treatment process or the specific area analyzed-most of them Valencia Region. And although almost all of the studies refer to a specific year, that of Hernández-Sancho et al [21] uses a six year period.…”

“…Although it is true that, for Spain, quite a few have been published in this regard over the last few years. See, for example, Molinos-Senante et al [17][18][19], Lorenzo-Toja et al [20], Hernández-Sancho et al [5,21,22], Sala-Garrido et al [23][24][25], Hernández-Sancho and Sala-Garrido [26,27]. On the international level, mention should be made of the research carried out by Mahmoudi et al [28] for Iran, or De Jong et al [8], Kemp [29] for the Dutch WWTPs and Gerrini et al [15] for the Danish water services and WWTPs.…”