Wastewaters contain
energy, in the form of biodegradable organic matter, that we
expend energy to remove rather than trying to recover it
Besides, there is a continuous global concern on environments and
shortage of energy from fossil fuels like pollution and global
warming with the exponential growth of population This
trend has triggered global movement towards the generation of
renewable energy by developing new technology and engineering
systems which are not only sustainable but clean and
environmental-friendly. There are some hybrid technologies
which are promising and yet completely different approach to
wastewater treatment as the treatment process can become a
method of capturing energy in the form of electricity or hydrogen
gas, rather than a drain on electrical energy