Results demonstrated that increase of MLSS decreases the total project construction, material and amortization costs of WWTPs containing EAAS and CAS.
Besides, increase of MLSS does not affect costs of WWTP containing SBR, but increase of this value decreases the total project construction, material and amortization costs of WWTPs containing EAAS and CAS.
These results demonstrate that increase of MLSS does not affect costs of WWTP containing SBR, but increase of this value decreases the total project construction, material and amortization costs of WWTPs containing EAAS and CAS.
And even that gets confusing, as some covenants are transparent and discussed up-front, while others are of the sneaky-hidden type, such as sudden amortization triggers, material adverse change (MAC) or "investor abandonment" clauses.
The total project construction cost and the total operation, maintenance, material, chemical, energy, and amortization costs ($/year) of case 1, case 2, case 3, and case 4 are shown in Figs. 4 and 5, respectively.
Three configurations for a wastewater treatment plant in Tehran city were proposed and the total project construction, operation, maintenance, material, chemical, energy and amortization costs of these WWTPs were calculated and compared.
Open image in new window Fig. 6 The total project construction cost of WWTPs containing EAAS, CAS, and SBR processes Open image in new window Fig. 7 The total operation, maintenance, material, chemical, energy, and amortization costs ($/year) of WWTPs containing EAAS, CAS, and SBR processes.
The total project construction cost of WWTPs containing EAAS, CAS, and SBR processes at different MLSSs are shown in Fig. 8 and the total operation, maintenance, material, chemical, energy, and amortization costs ($/year) of WWTPs containing EAAS, CAS, and SBR processes at different MLSSs are given in Table 6.
In this study, three configurations containing conventional activated sludge (CAS), extended aeration activated sludge (EAAS), and sequencing batch reactor (SBR) processes for a wastewater treatment plant in Tehran city were proposed and the total project construction, operation labor, maintenance, material, chemical, energy and amortization costs of these WWTPs were calculated and compared.
In this study, three configurations for a wastewater treatment plant in Tehran city were proposed and the total project construction, total operation labor, total maintenance labor, total material, total chemical, total energy and total amortization costs of these configurations (plants) were calculated and compared.
