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