Water Pollution 

Aim 
To create awareness to the student community about the causes of water pollution, water scarcity in Chennai and the measures taken and suggested by various groups of people.

Activities

• Testing of water samples in science lab and TWAD board
• Group discussion on the causes of water pollution and the solutions to overcome the scarcity of water in Chennai
• Poster making on ‘SAVE WATER & SAVE LIFE’
• Working model on Aquifier, RO and sewage treatment plant.
• Map activity on identifying locations of sewage plants in Chennai.
• Presentation of all the work on Science Fair

Work Done

We collected water samples from various localities. General testing like colour, odour and pH was done in the science lab. Comparison of samples was done in TWAD Board (water authority in our locality) on the basis of pH, turbidity, temperature and suspended impurities and results were recorded in a datasheet. The conductivity varied for different samples due to differing mineral content. All the results were presented on a poster. During the visit to the TWAD office, we enquired about the reasons of water scarcity in our region and the measures taken by the Board. The steps taken include rain water harvesting, as the Chennai region is getting good rainfall these years and installation of various desalination plants. The private water provision is rapidly increasing where water is purified and packed at private plants. We also had a group discussion in class. A poster presentation was done on the topic ‘Save water & Save life’. A map activity was done to locate the water treatment and sewage treatment plants in our region.

Four models were constructed by us- aquifer, RO , sewage treatment plant and solar filter. Contaminated water was tested with the techniques included in the model like charcoal extraction, screening, sedimentation, coagulation using alum, secondary filtration , checking the acidity level, etc. The treated water from the sewage was purified with the RO model. The final checking was done with the universal indicator and the pH meter, the value being 6.8.

Some of the better purification methods which we included were the use of activated carbon and reverse osmosis. As carbon is only mildly effective in filtering out particulates and microorganisms, it is mostly used as a second or third stage filter in home and portable water use. It was used in conjunction with reverse osmosis in our model. All the models, posters and charts were presented during the school’s Science Fair.
 

Findings

• The water samples collected were mostly ground water and the conductivity varied. The conductivity of water is high if the water flows through a granite bed rock and low if water flows through areas with clayey soil. Ground water inflows can have the same effects depending on the bedrock they flow through.  
• The water scarcity in our region is due to geographical location- the city lies on the coast of bay of Bengal even though few fresh water bodies are nearby. Another reason is the population which is almost sixty lakhs. People rely on bore wells to get sufficient water. Due to the increased stress on ground water, the level has fallen by more than four meters; it may soon become unfeasible to obtain ground water.

Recommendations

• Reverse osmosis combined with activated carbon seems to be the best purification method as it removes total dissolved solids, turbidity, chlorine etc.
• The degree of treatment required will vary according to the type of  water received.
• Though solar filters rarely produce enough water for long-term survival, it could provide an important means of potable water in the event of an emergency. 

Visit to TWAD

Presentation of the models