Page 46 - Materials Chemistry, Second Edition

Ecological Assessment 27

TABLE 2.2
Multipurpose Schemes in Switzerland: Operating and Remaining Potential

Number of Output Production
Water Network Type Potential Type Sites (MW) (GWh per year)
Drinking water Operating 90 17.8 80
Remaining 380 38.9 175
Treated waste water Operating 6 0.7 2.9
Remaining 44 4.2 19
Raw waste water Operating 1 0.38 0.85
Remaining 86 7.1 32
Source: ESHA (European Small Hydropower Association). Energy Recovery in Existing Infrastructures
with Small Hydropower Plants: Multipurpose Schemes—Overview and Examples, 2010.

and the analysis of the measured data by an expert are key steps in reducing the
uncertainty related to the energy yield assessments. Ak et al. (2016) used a fuzzy
logic decision analysis tool to select the most appropriate low-head hydro turbine
alternative at the outlet of WWTPs, and they found the Archimedean screw to
be the most suitable technology for hydropower development at the outlet of a
WWTP due to its superior performance according to economic and environ-
mental criteria. In this context, this study aims to show the possible benefits of
the installation of a hydro turbine at the outlet of a WWTP. This could be an
alternative clean energy solution to reduce the consumption of energy supplied
by the national electric grid, mostly fed by fossil fuels, and to induce the mini-
mization of CO emissions to the atmosphere. Energy recovery efficiency, ER, is
2
calculated from

E
ER = (2.2)
E c
where:
E is the generated electricity
E is the electricity consumed by the facility
c

2.4 CASE STUDY: TATLAR WWTP
Tatlar WWTP, which is the one of the biggest WWTPs in Europe, has been
operated by the Municipality of Ankara since 1993. The combined sewer sys-
tem carries domestic and industrial wastewater and rainwater by gravity, and
there is no need for pumping. Because of its high population and industrial
activities, Ankara produces an enormous amount of wastewater. The waste-
water of Ankara metropolitan area is discharged into Ankara Creek. The
3
plant was built as an active sludge project with 765,000 m per day wastewater