In addition, a Case Study in the city of Geneva (Switzerland) was selected, where a pre-treatment was
applied and an energy balance was performed in order to justify the energy neutrality of the process. The
energy cost in the Canton of Geneva for Services and Utilities (including WWTP) is 0.083 USD$/KWh
[12], while in Mexico city is 0.107USD/KWh [13]. In other words, the energy supply in Mexico is as
expensive as in Switzerland. This comparison opened a new chapter for re-thinking about the possibility
of using pre-treatment for enhancing the production of GE (CH4/H2) in WWTP in Mexico. The Case
Study is expected to be used as a benchmark for WWTPs in Mexico. The first possible implementation is
at Mega WWTP in Atotonilco de Tula (Hidalgo).