Saving A Million Litres Of Water Per Factory
[Applause]
back in november 2014 the city of
chennai was flooded
there was a tropical storm the entire
city was under water
and there were wide range across the
state of tamil nadu
the tropical storm named nilofer not
only left
the city of chennai in shambles the
torrential rains
that accompanied before and after the
cyclone
after the landfall of the cyclone
managed to flood open
flood the open wastewater treatment
plant at our denim processing unit
which was 400 kilometers away from
chennai
we contained the flooding inside our
factory pretty well
wherever the excess rains will store
water in various ponds
except for a leak of about 50 liters of
water
out of our effluent treatment plant yes
this 50 liters of water
leaked from our open wastewater
treatment plants
the wastewater treatment branch had a
capacity to store 10 million liters of
water
the plant was also designed for a normal
normal pass-through
or treatment capacity in excess of
million liters of water every day
so it has 10-day storage a million
liters of treatment capacity
10 milliliters of storage the small
leakage
made the authorities of tomorrow
pollution control board issue as a
closure notice
we were asked to close down shutdown of
factories shut down our operations for
two weeks till we rectified a defect
what was the defect
it was just an impul simple overflow
from the plant
flooding but thanks to this close notice
it was a blessing we think it was a
blessing for us it made us to think
it made us to think why send so much
water
to the fluent treatment plant we had two
options one cheat
cheeton water treatment or just innovate
innovate and innovate and send less
water and keep your effort treatment
plant empty and ideal
we took the second route how to reduce
our different increment capacity last
through every day
how to keep a reference treatment plan
empty and how to protect ourselves
from any such future incidents and here
began an idea
for water accountability on the machine
which led to water sustainability hi
i am srihari balakrishnan and what is
sustainability mafia also
and i am going to talk about water
accountability
and how we have innovated on a water
treatment
how a perception of wastewater
has changed over the years and why we
think today
wastewater is nothing but pure gold
so let me first state the objective that
we achieved
we had a million liters of treatment
capacity with 10 milliliters of storage
what was the objective achieved today
we brought it down to treating just 50
000 liters per day
yes instead of treating today a million
liters of wastewater we are treating
only 50 000 liters every day
a 95 percent reduction volume of
wastewater treated in our open fluid
treatment plants
95 reduction a million liters brought
down to 50 000
per day to get this from million liters
to 50 000 liters
let me tell you how we understood what
we did
how we worked before and how we change
the way we work how are we working
before
we were working before as follows
in any textile or other processing
industries there’ll be
a lot of wastewater streams coming from
different parts of the machine from
different processes our plant had 50
streams
a typical plant will have anywhere from
50 to 100 streams of
wastewater streams fresh water will be
given to all these areas and then from
which wastewater will be squeezed out
dyes and chemicals use water as a
transfer medium
dyes and chemicals are added fresh water
applied to fabric or leather squeezed
out and the water will reach
the homogenization tank all this water
is then consolidated
so some streams will have high ph some
streams will have low ph some streams
will have
high temperature low pressure so all
these some streams will you have dice
some strings will have color
so the 50 strings will consolidate
and take it to a homogenization
what we did was study first each of
these streams separately
high ph water stream separately the low
ph water stream separately
high temperature water stream separately
the water with color
stream separately the color stream
separately
some streams will also have dyes in
exhausted chemicals because when you
apply dye
the dye has to exhaust itself onto the
fabric the remaining die will get washed
away only sixty percent dies
sixty percent of guys get exhausted onto
the fabric the other forty percent will
go down in the wastewater stream
we are homogenizing all these streams
with different
and varying properties some of these
teams will have a combination of two or
three
properties for example the indigo base
team will have indigo in it
ph also will be high it will also be
high high temperature
so we studied these streams for some
streams for one year
stumps streams for 18 months some
streams we continue to study
even today because we need to find
solutions for all these
wastewater we need to find use cases for
these wastewaters
we need to find fresh usages we need to
convert this
wastewater streams into good use strips
we what we found in these streams is
that there was a remarkable consistency
in the properties of these streams
the ph the ph was within a certain
bandwidth
temperature the temperature was within a
certain bandwidth
there was drying in the stream the
residual dye had a certain milligrams or
certain parts per million and it was
within a certain allowable range
this started marist to start thinking
about the use cases
first the consistency itself was a
revelation to us
the consistency we thought you know
there will be big fluctuations but the
consistency itself was a revelation
the second thing was each of these 50
wastewater streams mentioned
the properties we started jotting down
we started knotting down
started figuring out let me give you an
example of how we did it
the indigo wash water stream we found
that there was indigo wash water in it
for a very large volume capacity it had
a high ph ph of around 12
and also high temperature in at 60
degrees temperature
we figured out that we could through
innovation
both chemical separation and mechanical
separation
we could take the indigo day into a
separate concentrator
the high ph stream with the temperature
we could we could take it out separately
what we did was we reused the indigo dye
stream
back into the process we recovered all
the indigo data that was going wasted
back into the process
we took the high ph water to fabrics
covering
so we today became a zero indigo waste
company with a die update of ninety
percent
sixty percent dry uptake became a
dietetic of ninety percent
now that the indigo dye was removed
there was no color in the second stream
we reuse the colorless high temperature
high ph
waste water to cover our fabric fabrics
covering happens at high temperature and
high ph
so what we did was we removed the indigo
dye we were able to reuse
did we stop with this no we did not stop
with this
typically wet scrubbers are found in
most fabrics
for the high ph stream we found a second
usage
with scrubbers what they do is the
exhaust glasses are first wet scrubbers
scrubbing in with water the smoke is
exhausted we’ll have we will scrub it
this
wet scrub is to remove any toxins in the
smoke like sulphates and carbonates
and capture them as sulphuric acid and
carbonic acid
and there’ll be more other kinds of
assets we figure out
that which crap i have when scrubbing
happens more efficiently
using the marginally high ph water than
a normal or low ph oil
in an acidic water which grabbing
doesn’t happen in a normal
in a high ph water there are more
hydroxyl molecules in the pi
ph water and fusing of the toxins
happens better
sulfur dioxide toxins
fusing with water carbonic carboxylates
fusing with water habit
and a scrubbing efficiency went up from
70 percent
to 95 percent so what we did was
we take this high ph water after fabrics
covering or washing
to a wet scrubber so one water indigo
dye
fabrics covering we’re going to do a
with scrubbing
one water three uses three fresh water
streams got
reduced to one freshwater stream and
one wastewater stream was used two more
times
before it was sent to the effluent
treatment plant
continued our research trial and error
on all the 50 different wastewater
states
one stream at a time and we have today
reduced the number of streams going to
the effluent treatment plant
to the wastewater treatment plant to 10
streams
10 wastewater streams are pretty
homogenized and treated
we continue working on it we believe
that we can reduce this further to five
or six streets
from 10 streams we think we can bring it
down to five or six streams
today one million liters of waste water
treated has come down to 50 000 litres
of wastewater treated per day
and we think we can bring it down to 30
000 liters per day
six years of research 500 million liters
of fresh water drawdown reduced
250 million liters of waste water not
treated
not a gram of indigo dye sent to the
wastewater treatment plant
90 indigo recovery 35 percent less
indigo consumed for the denim
for the same shade of light
thanks to micro cyclonial offer
thanks to the closure notice issued us
thanks to our innovators each one of who
is the chief sustainability officer
400 of our factory members are chief
sustainability officers today
really looking back we’re very happy
about what we did
we happened to be the world’s only zero
solid discharge zero liquid discharge
denim practice
we happen to use only six liters of
water to make a meter of denim
as compared to anywhere any other
closest competition which is a 60 liters
to 120 liters
to make a meter of denim just imagine
what the entire textile and leather
industries thought on this lens
how much usage of fresh water will get
reduced
and how much waste water will get
reduced how many use cases will be there
for wastewater streams
how much dyes and chemicals will get
reduced how much
electricity the pump and store all this
amount of water will get reduced
this is total circularity total
sustainability
i would like to close this with one
statement the amount of
fresh water we reduced can
be used for drinking water purposes for
a town
of a million people 10 lakhs with just
100 denim factories
hundred tons each of a million people
will have drinking water