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Water is the petroleum of the 21st century. (Yao Graham)
Mughal
emperor Akbar built a majestic fort at Sikri near Agra, India and named it
‘Fatehpur Sikri’ (City of Victory) after Emperor Babur’s victory over Rana
Sanga. It was his headquarters for 14 years from 1571 until 1585. Ironically,
the fort built after victory in battle was abandoned due to lack of water and
Akbar relocated to Agra Fort near the Yamuna River. Similarly, Kampuchea’s
Angkor-Wat civilization thrived for centuries, but ultimately collapsed when
its elaborate water storage/ supply system broke down. Water has been the
lifeblood of all civilizations and remains vital. The water supply/ drainage
system of Indus Valley civilization was commendable for that period, but the
same will not work now.
Water (covering 70% surface) and
clouds give Earth a bluish-white appearance from outer space. Of all water on
earth, 97.19% is saline and 2.2% is underground or in polar ice-caps; leaving
only 0.61% as fresh usable water. It exists as ice (solid), water (liquid) and
vapor (gas); and its constant conversion from one form to another moderates the
climate and gives our familiar seasons. Water cools, refreshes and rejuvenates.
This universal solvent cleans everything by getting itself dirty, but leaves no
taste, smell or color. Water is a living magic and sustains life. When cooled,
it gradually contracts and is most dense at 4˚C; on further cooling it expands
and freezes at 0˚C. Floating ice insulates the relatively warm water beneath, helping
aquatic life to thrive even when the air above is far below freezing. Water cannons break up violent mobs; the term
‘hydraulics’ comes from incompressibility of water; and ‘hydroelectricity’ is
generated from potential energy of water. Water is taken for granted and the
terms ‘On Tap’ for ‘freely available’ and ‘Down the Drain’ for ‘sheer waste’ come
from its abundance; but a crisis is imminent.
A
privileged few have purified water for everything; from cooking and bathing, to
flushing toilets. Common drains take wastewater to effluent treatment plants (if
existing), otherwise directly into rivers. Indian cities
produce about 62000 MLD (million liters daily) of sewage, of which 39000 MLD is
released untreated for want of infrastructure, time or energy. A fast growing population needs
increasing amounts of good freshwater, but sources are limited/ polluted.
Mumbai gets over 3000 MLD of water, and this
requirement may increase to 6300 MLD by 2021. Tankers supply water worth Rs 3600 Crores a year in Mumbai
alone and 20-50 liter packs of drinking water sell for Rs 40-200 each. Saudi
Arabia relies solely on groundwater, which may run out in the next 13 years. Cape Town is the world’s first
big city to run out of water now. Diverting water only for human consumption degrades
the natural habitat of a variety of flora and fauna; causing a severe
environmental impact. People waste water as heavily subsidized water purification
and supply system (with neither punishment for waste nor incentive for saving)
makes them unaware of its true worth. Lack of water in inhospitable terrain constrains
military operations, which I experienced during a competition run of Camp Rover
in NDA. My squadron mates and I had
started the cross-country march before dawn; with my only water-bottle empty, fatigue
and dehydration seemed inevitable. Around sunrise we reached a hill where tall
dew-laden grass soaked me up to the chest and water dripped off my fingertips.
Dew, being almost like rainwater, I quenched my thirst by drinking the water
that dripped off my little finger on lifting my elbow.
Wastewater. The more water we use, the more wastewater we produce;
one liter of sewage pollutes eight liters of water and contaminates
groundwater. Water purification is both difficult and costly downstream of
polluted rivers (e.g. Ganges and Yamuna). Wastewater
can be reduced by reusing water in laundry washing machines (reusing first
rinse for prewash and second rinse for wash cycles to save 50%) and recycling to
recover pure water and concentrated residue. Green Buildings require minimal
resources (including water) and produce little or no waste. Water should ideally
be supplied by separate pipes for the required use (purified for drinking,
cooking and bathing; and raw for flushing and horticulture). Wastewater should be segregated into separate drains for
reuse/ recycling as follows: -
§ Green Water.
It is the bulk of wastewater from kitchens/ bathrooms. Suspended non-toxic
bio-degradable organic matter settles down on river/ lake beds. Methane produced
by anaerobic decomposition is probably the cause of fires on Bengaluru lakes. Roots
of Cannas/ banana/ bulrushes/ grass planted between the Blue and Red
flood-lines of rivers (where construction is banned) bio-filter this sewage and
the clarified water can be used for horticulture/ flushing or released safely
into water bodies. The perennial greenery sequesters carbon dioxide and acts as
the city’s lungs.
§ Gutter Grease. Cooking oils and fats
coagulate in cold weather and putrefy during warm weather to produce methane. Gutter
grease can be collected in grease traps and converted into bio-fuel.
§ Fecal Matter. There is a mental block against
treatment facilities for fecal matter near habitation. This can be bio-filtered
in isolated vegetation patches between the Blue and Red flood-lines and the
clarified water released into the river.
Aerobic composting eliminates methane and makes energy intensive STPs redundant.
§ Red Water.
This wastewater has a high proportion of potentially toxic TDS (total dissolved
solids); detergents from domestic sewage and chemicals from industrial effluents.
Zero-discharge of Red Water by segregation and complete recycling prevents
water pollution.
The Natural Water Cycle. The water cycle creates rivers (conveyor belts of
life) that deposit silt to make the plains fertile. Water vapor is produced in summer when temperature is far
below the boiling point of water; and precipitation occurs during the (heat-index-wise)
hottest part of the year. The water cycle replenishes reservoirs whose
capacity is reduced by silt. Most underground aquifers are depleted faster than
natural percolation can replenish them. The summer flow of glacier-fed
perennial rivers is reduced as glaciers recede due to global warming. Climate
change causes floods, droughts or untimely precipitation, which affect food
production adversely.
One evening we had a good shower
at our campsite in the midst of a 1000 m wide tree belt planted all along Indira
Gandhi Canal. Surprisingly, not a drop fell on barren sand dunes just a few
kilometers away; proving that the trees had facilitated the precipitation. Reforestation
of barren land will check climate change and prevent drought. Forests prevent
soil erosion, facilitate subsoil percolation and sequester carbon dioxide.
Traditional
houses in semi-desert Rajasthan store rooftop rainwater in underground tanks
for the year’s drinking and cooking. However, Rainwater Harvesting is possible
only during the monsoon and is limited to storage and treatment facilities. It will
help to understand how the Bishnois’ sustainable lifestyle has conserved the
delicate environment of Rajasthan’s desert. Weather is a complex phenomenon that
depends on numerous variables. Environmental amnesia makes us forget that there
was no atmospheric haze before climate change became a serious problem. A
simultaneous increase in fossil fuel consumption and deforestation (reduced
carbon sink) has compounded the problem. Nano-particles of SPM being dark
absorb solar radiation and contribute directly to global warming. Warm air holds
more moisture to cause cloudbursts, storms and cyclones. Ionization effect of
vegetation will reduce suspended particulate matter (SPM). Unnecessary burning
of garbage and biomass should stop. The poor who rely on solid fuels would
benefit from improved smokeless stoves.
Replication of Water Cycle. A survival technique (Solar Still) replicates
the water cycle on a small scale, where a clear plastic sheet over a pit
produces water vapor by day and water at night. During
monsoons in Mumbai, water condenses on single-sheet glass windows of AC rooms
with the inner surface barely 5 – 6°C cooler than the outside. Water also
condenses inside discarded PET water-bottles over a day/ night cycle. This phenomenon is
attributable to high
relative humidity and a small temperature difference. The myth that distilled
water is completely de-mineralized and hence not potable lacks credibility,
because simply adding the required quantity of essential minerals gives ideal
drinking water.
Water cannot be
produced/ manufactured, but reduce (usage), reuse and recycle (by an artificial
water cycle) is imperative. Distillation and Reverse
Osmosis involve huge infrastructure/ energy and are unviable. Innovations like Atmospheric Water Generator and Seawater Greenhouse have limited output. During Prime
Minister Shri Narendra Modi’s Israel visit, he was shown the GALMobile,
a Jeep-like vehicle that produces pure water from wastewater/ seawater.
Problems. Huge quantities of wastewater and
low-grade waste heat need considerable energy and infrastructure for treatment/
disposal. Cooling tower of chillers/ central AC plants consume about 1000 KwH
of electricity each and treating 300 KL effluent costs about Rs 6000/- per day.
Proposed
Concept. A hermetically
sealed system for vacuum-aided low-temperature distillation of liquids called RENEWATE
gives a continuous supply of clean freshwater (in compressed
time/ space). A warm
evaporator contains a batch of saline/ wastewater and the relatively cool
condenser collects pure distillate. An active system helps to maintain the
maximum possible temperature difference between the evaporator and condenser. Low-grade
waste heat from compressors, engines, etc makes the system work as a super conductor for rapid heat exchange. Pure
water can be recovered from seawater, industrial effluents and sewage; and
solvents from chemical processes.
A small-scale working model has proved the concept and can be scaled up. Working
conditions in the system are created and maintained with very little energy; and
the power saved is power generated. Patent applied for vide 1186/MUM/2010 dated
09 April 2010 and Trademark RENEWATE on 10 November 2011.
Comparison
with Existing Systems.
§
Works as
advanced radiators and cooling towers.
§
Works as a
combined water purification and effluent treatment plant.
§
It is an advanced
version of Seawater Greenhouse and Atmospheric Water Generator.
Possible Variations. Various possible applications of RENEWATE are as follows: -
§
Produce
pure distillate and concentrated residue to recover chemicals.
§
Concentrate
seawater into brine/ salt.
§
Symbiotic functioning
of cold storage chillers with sugar mills uses waste heat to concentrate
sugarcane juice.
§
Concentrate
milk and fruit juices in food processing.
§
Work as a
home heating system in extremely cold climates.
§
Produce
freshwater in ships.
§
Provide
efficient heat sink for compressors in green buildings.
Advantages/ Benefits.
§ Low-grade waste heat/
solar heat and wastewater/ seawater are utilized as resources to produce concentrated residue and pure water, which are both useful.
§ Water purification/ effluent
treatment plants and inefficient radiators/ cooling towers become redundant.
§ Provision of pure water to
survivors of natural calamities prevents waterborne diseases, which cause 88%
of avoidable deaths. Pure water is produced from
brackish and arsenic/ fluoride contaminated water.
§ Reforestation of barren areas alleviates climate change and sequesters carbon dioxide.
§
Bottled water is redundant, eliminating the environmental cost of
packaging, transport and waste disposal.
Conclusion:
RENEWATE converts abundantly available wastewater/ seawater into pure water at virtually no cost, using
up low-grade solar/ waste heat. Existing
aquifers are already inadequate and new dams that submerge forests, agriculture/ grasslands and
displace people are not needed. Mass migrations from water-stressed areas
(like Syria) can make situations like Angkor Wat possible. Clean water from RENEWATE can make
coastal areas self reliant round the year. Industrial effluents are converted
from a liability into assets (pure water and recovered chemicals) and
zero-discharge eliminates pollution. RENEWATE can be the foundation for
‘green’ sustainable development by recycling waste and reducing cost. Its potential benefits, like the
value of a head load of water carried over long distances by women in water
deficient areas, are difficult to quantify. RENEWATE integrates
‘Ecology’ with ‘Economy’ with great potential for long-term financial benefits, plus intangible benefits of
improved health and environment.
Forestalling
environmental crises can be a thankless job. People won’t realize that a
problem has been solved/ averted because they can’t see it anymore; just like the
people of Hamlin, who forgot their promises after Pied Piper got rid of the
rats.
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When the well is dry we know the worth of
water. (Benjamin Franklin)
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We have not inherited Earth from our ancestors; we are merely
borrowing it from future generations.
