Page 30 - Biotechnology newsletter 2023-24

Field trip to Sewage treatment plant, Tonca Goa.

As part of our field trip, the F.Y.B.Sc Biotechnology class accompanied by
Ms. Swaroopa Naik visited the sewage treatment plant in Tonca, Goa. It was truly
an enriching experience wherein we witnessed our theory come to life
Our guide for the day, Mr. Nikhil Sawant, an engineer at sewage treatment
plant first took us to the site of raw sewage intake area where sewage from
Taleigao & the outskirts of Panaji first gets collected in the dump where it is
screened & then pumped for primary treatment. Primary treatment involves the
removal of soil, sand, grit, oil & grease. For this purpose, the sewage is passed
through fine screens followed by sedimentation chamber where heavy particles
settle down and then to oil & grease removal chambers where the top 2cm of
water is removed. This is followed by the secondary treatment. The Sewage
treatment plant contains two secondary treatment tanks. The primary effluent is
pumped into these tanks and then aeration is carried out with the help of blowers
for the growth of aerobic microorganisms in one tank. In the other tank, flocs
settle down and are decanted as clean water rises. The water is then chlorinated,
tested and discharged into the Mandovi river. The activated sludge on the other
hand is pumped out, collected, and dried in centrifuge and sold as manure.
Toward the end, Mr. Sawant explained the difference recorded in the
parameters of sewage water and chlorinated water. The end of the field trip was
marked by a group photograph.

~ Aloma Saldanha
F.Y.B.Sc. Biotechnology

Mr. Sawant explaining the working of sewage treatment plant to the FY students

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