Page 45 - Materials Chemistry, Second Edition

26 Life Cycle Assessment of Wastewater Treatment

Raw
wastewater
influent
Digested screenings/grit
disposal
sludge
Primary
settling
Gas
storage
tanks Aeration
tank

Secondary
settling
Biogas
power
plant
Treated wastewater
influent
0 100 Hydro
N Scale power
plant
ANKARA STREAM

FIGURE 2.1 Layout plan of the Tatlar WWTP.
WWTP. The four hydro turbines installed at Samra WWTP will generate 21 GWh
per year electrical energy, which has important environmental benefits, as Jordan
generates its electricity mainly from oil. This production is estimated to avoid the
emission of more than 17,000 tons of CO per year. Also, the facility covers 98% of
2
Amman city’s electricity consumption by using the biogas and hydropower (at both
inlet and outlet) energies together (ESHA, 2010).
In the case of hydro energy, electric generation, E, is proportional to the dis-
charge, Q, and the head, H, as follows:
E =ρ gQH tη (2.1)

where:
−3
ρ is the density of fluid (ρ wastewater = 1080 kg m )
g is acceleration due to gravity
η is the efficiency of the hydro turbine for the corresponding discharge
t is the working time of the turbine for the relevant time period
Assessing reliable and sufficient discharge data during the planning phase of
a hydropower development is necessary to accurately estimate the hydro energy
yield. Accordingly, long-term (at least 1 year) on-site discharge measurements