The sem 6 BBA students were having their Environmental Sustainability class this morning and there was an interesting guest speaker who came in. Sunny Daniel, IIT Kharagpur was involved in many water treatment projects in the past and is presently working at the Acharya School of Design in Mysore.
Sunny was managing the water treatment plant at Puravankara Complex, about 1000 flats in Marathahalli, Bangalore, as he was staying there. He was the very few knowledgeable people in the colony who understood the need for water treatment and water conservation and was voluntarily looking after the sewage treatment plant for many years.
As per the talk, each of the ten major high rises in the complex have three water tanks on the terrace and one water sump underground. The underground sump helps collect the Cauvery water water which comes very rarely, if not never. The bore well water and tanker water besides some rainwater harvesting water. On top of each of the ten residential blocks, there are three water tanks, one for the fire hydrant system, second for the drinking water that comes from the sump in each building that collects drinking potable water fit for human consumption.
The third tank atop each block carries the water that comes from the water treatment plant and goes to the toilet flush in each flat. The lines are specially coloured to ensure that the treated water does not by any chance leak or mix with the potable water.
The effluent treatment plant collects the waste water that comes from the bathrooms and kitchens from all flats, black water and grey water, and passes them through coagulation and flocculation, sedimentation process in about 5 tanks before pumping the output, filtered water, unfit for human consumption, to the respective tanks atop each of the ten buildings to give to the flushes in each house. Part of the recycled water is also taken for gardening around the complex. One of the most effective principles of water conservation, proper recycling of water is thus well practiced here.
The city of Bangalore has many such high rises and water usage and recycling through water treatment process though offers great savings in water usage continues to be a big challenge in all these apartment complexes. An audit could be done in some of these complexes to understand the gravity of the situation.
Visit to AU Sewage Treatment Plant
Immediately afterwords we went to the AU water treatment complex at the south east corner of the campus. Both the plants 2 lakh litres per day and 2.5 lakh litres per day plants were functioning, as the campus has maximum occupants now. At full use the Alliance University campus needs almost 5 lakh litres of water daily, considering 10% of this is lost or absorbed, the other 90%, almost 4.5 lakh litres is treated and used. The grey and dark water from the hostels and mess halls are allowed into a sedimentation chamber where all suspended and heavy solids are removed initially. The water is taken for aeration into an open chamber where the suspended organic matter is allowed to oxidise, this removes the bad odour.
After filtration through three chambers, the final water is allowed to settle in a tank. This water is very transparent and looks just like other drinking water except that it is unfit for human consumption.
As different from the earlier case, here the recycled water is not taken to the toilet flushes in the hostels and is used only for watering the greenery in the campus.
Benefits :
The water treatment inside the campus helps prevent wastage of fresh potable water for the greenery. The RWH and WT plant saves the campus millions of litres of water and thus helps contribute in a great way to environmental sustainability.
The author having worked with industrial water treatment plants in MRF Tyres in Goa is experienced in systems where softening of the water is the most important criterion before it is emptied to the Khandepar river .being industrial use the water is not used for human consumption at all and is released to the river after treatment and bringing it to ambient temperature. Clearing the water of pathogens and making it potable for human consumption is not the criteria as much as removing the chemical ingredients in the water in industrial water treatment.
With the onset of the urban dwelling culture and consumption of water on the rise in the cities and urban areas, effective water treatment and water recyling policies is very much needed for the health growth of societies and communities.
George.
No comments:
Post a Comment