Bio fuel generation from waste water treatment

There has been a continuous increase in the energy demand over the years which are expected to rise with time. Fossil fuels are not being a sustainable source of energy due to green house gas emission which has significant impact on environment. Green unicellular micro algae have been identified as potent sources of renewable energy. Microalgae can generate significant extent of bio mass and oil suitable for conversion of bio diesel. Micro algae have higher bio mass productivity than plant crops with regard to land area for cultivation, reduced GH emission and lower cost. Kerala produces lot of domestic and industrial waste water that often reaches water bodies rapidly and impairs the reuse of this water for domestic and agricultural purpose. Reuse necessities removal of high concentration of nutrients particularly N and P which is left to accumulate in rivers and lakes can lead to high risk of eutrophication. The conventional method of removal of P is by precipitating the P using chemicals or is converted to bacterial mass as activated sludge.
The current scenario on algal biofuel technologies available for an alternative source of energy is likely to be economically non viable. However, dual and multiple use of algae for waste water purification , algal biofuel production and carbon dioxide sequestration by micro algae is an attractive option with respect to cost effective energy and nutrients as fertilizer, carbon dioxide capture etc. the high biomass productivity indicates the potential generation of bio fuel by micro algae as one of the renewable and sustainable methods.

BIO methanisation technology options

1. Energy recovery maximisation (60-98 % conversion to biogas)
2. Plant nutrient and organic matter return to crop land (c.8and least5 % N recycle)
3. Highest recycle potential environmental footprint (of other components of (USW)
4. Lowest level of secondary wastes (practically none)
5. Largest number of potential beneficiaries involved.
    They could also be altered to produce a variety of intermediate products, bio-hydrogen, bioelectricity, etc.     thereby making a multiproduct option and gradually promoting the concept of decentralized bio refineries.