I might be able to answer if you could tell general properties/characteristics of the waste water  

Mandavgane sir,  I haven't done the characterization of water because it is being found not suitable with existing methods. I got water from a oil refinery which is pitch black with odor same as petrol. I tried to find cod but after heating it became solid mass with very less liquid left. So most probably high total solid may be grease. Hence when put to aeration along with sewage water after 24 hrs it was unseparable mass of semi solid mixture which i had to discard.

you can use some kind of algae. Has been tried out already by Dutch company, if interested, can give you a link to them, and see what are the options. It can generate biomass but also feedstock for fish/cattle. So more commercially attractive. Some algae can be even provided to produce Fishoil!