Hi Rakshit Using algae to ...

Hi Rakshit

Using algae to treat sewage is the best solution. 

We have a process to grow Diatom Algae in sewage and in sewage polluted lakes.

100 kgs of Diatoms would consume about 8 kgs of N and 1 kgs of P and also consume 170 kgs of CO2 to produce about 120 kgs of Oxygen.

Thus the nutrients in the sewage can be used to produce all the Oxygen required to satisfy the BOD and COD.  

A retention time of at least 7 days  is required to grow enough Diatoms to consume the nutrients, since Diatoms can only grow at a certain pace and density. 

If retention time can be 30 days, you can even grow fish. The fish would consume the Diatoms and income from sale of fish would be more than the cost of treatment, so you can make a profit from sewage. 

Treated sewage with Diatoms in it can be released into lakes and rivers and the fish in the natural waterbodies would consume the Diatoms. 

If Green or Blue Green algae is used, you have to harvest the algae, this is expensive. That is why we are promoting Diatoms, since harvesting is not necessary and thus the process becomes economical.

In nature Diatoms dominate lakes and oceans, they account for about 40 to 50% of all primary production in water.