Purpose– Grey water treatment with the help of Algae Photo bioreactor.

First Setup-


Material used –

  1. Acrylic tube of Dia. 75 mm with 4mm thickness.
  2. Pipe fittings.
  3. Storage tank of 50 Ltrs. for grey water.
  4. Submersible Pump – Power-12W, Head- 1.6 Meter, O/P-900 L/H.
  5. PVC pipe.
  6. Blue LED of 10 Mtr. length.

Working of System:-

An alga is placed into photo bioreactor and grey water is passed through it. Due to light provided to algae, photosynthesis will happen and it will release Oxygen into water. And the result would be increase in Dissolve Oxygen.

Results of first trial:-

Initial DO readings before running system-

  1. 30/10/2017- 8:30 AM- 0.00 ppm (8:30 AM starting time of system.)


Readings after running system-

First trial ends on October 31, 2017 at 2:20 PM

Treated grey water sample-

DO= 2.01 ppm

On November 1, 2017

DO= 2.79 ppm

TDS=650 ppm


COD= 163.2ppm

Water temperature – 24.4°C.

Treated water 

As per calculations 9 rupees required to treat 40 ltrs of grey water.

**Second trial-

Starts on 3/11/2017

Readings before trial-

DO= 0ppm

pH= 7.64

TDS= 672ppm

COD= 255 ppm

Readings after 24 hrs-

DO= 1.23 ppm

Readings after 48 hrs-

DO= 1.32 ppm.

COD= 224.4 ppm

After second trial condition of scrubber:-


It is observed that scrubbers are not holding algae properly.

So after second trial some modifications in photo bioreactor are done.

New scrubbers and acrylic discs are added to plunger. Also nylon filters are introduced to hold algae properly.

Next trial is going on……