Water Treatment Project - A science expo in my School....

Wel come to my blog.. 

I wrote a small blog post @Life at Dharwad (blog by Sri.Siddesh Uncle) about my school. I thank Siddesh uncle for the encouragement.. I  am thankful to my dad for creating this blog for me. I 

This is my first blog post...

We had a science expo in my school. The topic of the project assigned this time was "Water Treatment Project". I searched internet for any models, though there were a few, it was difficult for me to get the items/materials required for the project. I took the help of my dad (who teaches Engg., Chemistry, in an Engg., college), he guided with a simple project. My grand father  bought the items and helped us to assemble the same.

Video : 

STAGE ONE: SCREENING: 

Screening is first stage of the waste water domestic treatment process. Screening removes floating objects like, diapers, nappies, sanitary items, cotton buds, face wipes and even broken bottles, bottle tops, plastics and rags that may block or damage equipment.  Special equipment is also used to remove grit that gets washed into the sewer. A RCC tank/Chamber is used to remove silt and grit.

STAGE TWO: PRIMARY TREATMENT (Clarifier): 

This involve the separation of organic solid matter (or human waste) from the waste water/domestic. This is done by putting the waste water into large settlement tanks for the solids to sink to the bottom of the tank. The settled solids are called ‘sludge. If settleable impurities are not removed easily, potash alum will be added and the forced precipitation leads to the  settlement of heavy impurities. At the bottom of these circular tanks, large scrappers continuously scrape the floor of the tank and push the sludge towards the center where it is pumped away for further treatment. The rest of the water is then moved to the Secondary treatment.

STAGE THREE: SECONDARY TREATMENT: 

The water, at this stage is put into large rectangular tanks. These are called aeration lanes/tanks. Air is pumped into the water to encourage aerobic bacteria to breakdown the tiny bits of sludge/organic impurities into CO2, water, nitrites, sulphates, phosphates that escaped the sludge scrapping process.

STAGE FOUR: FINAL TREATMENT:

Next the ‘almost’ treated waste water/domestic  is passed through a settlement tank. Here, more sludge is formed at the bottom of the tank from the settling of the bacterial action. Again, the sludge is scrapped and collected for treatment. The water at this stage is almost free from harmless substances and chemicals. The water is allowed to flow over a wall where it is filtered through a bed of sand to remove any additional particles. Final treatment like disinfection with chlorine gas treatment/chloramine/UV/ozonolysis leads to water free from pathogenic bacterii and finally the water is  sent to a storage tank. 

In case of domestic treatment secondary treatment is not needed, as water will be free from organic/in organic impurities...

 

The filtered water is then released into the river.