Need help regarding coagulant and flocculants?

[HasanAhmed]

I have a university project to design a simple ETP plant pilot project for a textile company to reuse their large quantity of waste water. After getting the effluent sample from the factory, i kept the sample for a day to settle down all the suspended particles. Then i take a small amount of sample and measure the pH, the pH was 7. Then I add almost 10 gram of alum in 30 ml of sample. It coagulates the particles and the dye color is almost gone. Then i filter it, to obtain a clear solution. The pH changes to 4.2. As the water is clear, I have a question that at this stage Is Biological treatment is necessary or the Phsico-chemical method will suffice?
And the pH changes because of alum then what I have to do to maintain the pH?
Can BOD and COD be removed by only this method? and by using ferric chloride and polyelectolytes this results can be achieved more better?
And actually what is the ratio of addition of chemicals as per the waste? (MOST IMPORTANT)

Kindly help me in this regards. I have attached pictures of results.

Thanks.

Hasan Ahmed

 

[bimr]

A small portion of the BOD and COD will be removed with your procedure. BOD and COD are soluble are need biological treatment for removal.

Neutralize to pH 6-9 with NaOH or Lime.

Regarding "And actually what is the ratio of addition of chemicals as per the waste? (MOST IMPORTANT)"

Do a titration.

 

[kybhosale]

You can use Fenton's Reagent for your study.

Regards,
Krunal

http://waterengineer.co.in