3. We are a company in the field of WATER
RECOVERY. Absolute Water Pvt Ltd., is an
integrated cleantech company that provides
turnkey solutions for converting waste into
most critical resource CLEAN
WATER. Leveraging its 30+
experience in technology development and
deployment, Absolute Water specializes in
Concept, Design, Erect & Commission of
complete water recovery systems. Absolute
Water can treat any kind of water irrespective
of its source or contamination level and
produce clean water, including 100%
drinkable water.
WHO WE ARE
5. MINISTRY OF ENVIRONMENT, FORESTS AND CLIMATE CHANGE
NOTIFICATION, NEW DELHI, 14TH JANUARY, 2016.
IN THE GAZETTE OF INDIA
S.NO INDUSTRY PARAMETERS STANDARDS
(1) (2) (3) (4)
4. SUGAR INDUSTRY EFFUENTS All concentration values are in milligramme
per litre except for pH
pH 5.5 -8.5
Total Suspended Solids (TSS) 100 (for disposal on land)
30 (for disposal surface waters)
Biological Oxygen Demand BOD
[3 days at 270C]
100 (for disposal on land)
30 (for disposal on surface waters)
Oil & Grease 10
Total Dissolved Solids (TDS) 2100
Final wastewater discharge limit 200 litre per tonne of cane crushed
(Final treated effluent discharge restricted to 100 litre per tonne of cane crushed and
waste water from spray pond overflow or cooling tower blow down to be restricted to
100 litre per tonne of cane crushed and only single outlet point from unit is allowed.)
TABLE : 1
7. ISSUES TO BE ADDRESSED
MAXIMUM REUSE OF WATER
EFFECTIVE MANAGEMENT OF
WATER & WASTEWTAER
STOP USING TUBE WELL
WATER DURING CRUSHING
SEASON
8. BIOGAS & POWER GENERATION POTENTIAL FROM DISTILLERY EFFLUENT
TYPICAL USAGE OF WATER IN THE SUGAR MILLS
IMBIBITION
BOLIER FEED
CONDENSER MAKE UP
COOLING TOWER MAKE UP
MILL BEARING COOLING
PUMPS SEAL FLUSHING
MILK OF LIME PREPARATION
SCRUBBING
EQUIPMENT WASHING
FLOOR WASHING
GENERAL USE (SERVICE WATER)
FIRE FIGHTING
9. A CASE STUDY WITH A TYPICAL 5000 TCD SUGAR MILL ON THE
WATER/WASTEWATER MANAGEMENT:
• Capacity : 5000 TCD
• Water in cane @ 69% on cane : 3450 Tons
/day or 3450 M3/day.
• As per CPCB norms, the mill can let out : 1000 Tons
/day or M3/day.
Based on the above simple evaluation the mill is supposed
to use 2450 M3/day water generated in crushing the cane.
10. WATER LOSSES IN THE SUGAR MANUFACTURING PROCESS
WATER LOSS ESTIMATION:
BASIS: 5000 TON OF CANE CRUSHED WITH THE FOLLOWING
COMPOSITION:
FIBRE : 14.5 %, SUGAR : 14.5 %, OTHER SOLIDS : 2 %, WATER : 69 %
1. BAGASSE :
% Cane = 30 %
Bagasse quantity = 300 T
Bagasse moisture = 50 %
Water in Bagasse = 750 T
2. FILTER CAKE:
% Cake = 4 %
Cake quantity = 200 T
Cake moisture = 75%
Water in filter cake = 150 T
3. MOLASSES :
% Cane = 4 %
Molasses quantity = 200 T
Molasses moisture = 10 %
Water in Molasses = 20 T
4. EVAPORATION LOSSES:
Through vents, spray pond drift losses, condensate cooling, ash quenching, etc.
Loss Through Vents :
Assumed as 1 % of steam consumption.
% Cane of steam consumption = 50
Steam Consumption = 2500 T
Loss Through Vents = 25 T
11. Evaporation & Drift Losses in Spray Ponds:
Amount of steam condensed is 25 % on cane, and is mixed with spray pond water,
which is 1250 T, of which 75 % is lost in spray ponds by evaporation.
Water Lost through evaporation & drift losses in spray pond
= 937.5 T
Evaporation loss in cooling excess condensate water
Approximately 4 % is lost in cooling the excess hot condensate water, which is 750 T.
Loss in cooling excess condensate = 30 T
Water usage for ash handling:
For ash handling approximately 3% of circulation water is required, which is 2500 T.
Water used in ash handling = 75 T
Recirculation Losses:
Losses due to natural evaporation will be around 1 % of the recirculation water –
Boiler water recirculation, Cooling Water recirculation and other mill water
circulation, which will be approximately 5000 T.
Recirculation losses = 50 T
Effluent generation:
Quantity of effluent generated = 500 T
Evaporation Loss during treatment = 20 T
Assuming a BOD of 3000 ppm maximum at the ETP inlet, quantity of sludge generated
after biological treatment is evaluated at the rate of conversion of 65% kg BOD to bio
sludge.
Kg BOD at ETP inlet = 1500 kg = 1.5 T Dry Solids
Moisture content of bio sludge = 80 % = 6 T
Treated effluent available = 474 T
TOTAL QUANTITY WATER LOST = 750+150+20+25+937.5+30+75+50+26
= 2063.5 T
12. Of the 3450 T of water generated in the crushing of 5000 T of sugarcane, a total
excess quantity of 1386.5 T or M3/day will be available for let out.
As per CPCB/Gazette 1000 T/day water can be let out for 5000 T crushed. Over all
excess water is 386.5 M3/day, so no need of bore well water in the Sugar Industry.
How to tackle this issue of 386.5 M3/day?
In most sugar mills excess hot condensate or cooling tower overflow is not recovered
or recycled. This is owing to the reason of the contamination levels and exorbitant
treatment costs.
Once this is done CPCB Norms will be fully addressed.
For this for a Sugar Mill of 5000 TCD excess condensate generated in Pan boiling is
estimated.
BASIS:
Inlet Brix to Pan : 65 %
Massecuite Brix : 95 %
Avg. massecuite % cane : 50 %
Avg. steam consumption % cane : 25 %
Based on the above let us estimate the water evaporated during the crystallization in
Pan Boiling process. All the steam supplied is condensed and is available for reuse.
Steam required for 5000 TCD = 1250 T/day
This quantity is fully available for recycle/reuse and once implemented will be
exceeding the limits of CPCB and also completely stop the usage of tube well water.
13. S.NO PARAMETER RANGE
1 pH 5.5 – 6.5
2 Chemical Oxygen Demand, (COD) mg/L 600 – 1500
3 Biological Oxygen Demand, (BOD) mg/L 150 – 300
4 Total Dissolved Solids, (TDS) mg/L 250 – 1500
5 Total Suspended Solids, (TSS) mg/L 150 - 300
PAN CONDENSATE RECOVERY:
Reasons for wasting the pan condensates is that, condensate is contaminated with sugar,
traces of Sulphites and suspended matter. This is reflected as in the typical average
analysis of the condensate as given below in Table.2.
TABLE : 2
14. CONTAMINANTS:
ACIDS (pH IS AROUND 5 – 6.5)
COD/BOD – DUE TO SUGAR ENTRAINMENT
TSS – DUE TO AIRBORNE DUST & BACTERIAL ACTIVITY
HARDNESS – DUE TO USAGE OF LIME SOLUTION FOR NEUTRALIZING
IMPLICATIONS:
ALGAL BLOOMS IN THE COOLING TOWER & CIRCULATION LOOP
SCALING IN THE LINES CIRCULATION LINES
FREQUENT CHOKING OF SPRAY NOZZLES IN CONDENSER INJECTION
AVAILABLE TREATMENT OPTIONS & DRAWBACKS:
COAGULATION/FILTRATION – LARGE AMOUNT OF CHEMICAL SLUDGE GENERATION LEADING TO
DISPOSAL PROBLEMS
MBBR SYSTEM – HUGE POWER REQUIREMENT (50 KW/hr for 1000 M3/day & ADDITIONAL SLUDGE
GENERATION.
MEMBRANE SYSTEM – ELABORATE PRETREATMENT REQUIRED, FOLLOWED BY HUGE CAPITAL
INVESTMENT AND HUGE OPERATING COSTS.
16. PROCESS FLOW DIAGRAM FOR RECYCLE OF PAN CONDENSATE
EXCESS
CONDENSATE :
COD : ~1200
ppm,
COOLING
TOWER
STORAGE
TANK
BIOFILTER
BIOFILTER
FEED PUMP
TREATED WATER
FOR REUSE
TARGET : COD < 150 ppm
17. BIOFILTER TECHNOLOGY
Bio-Filtration is emerging as an environmentally
sustainable, economically viable and socially
acceptable technology all over the world. The
process harnesses the energy, carbon and other
elements of the waste and converts them to
precious "Bio-nutritional" products like energy
rich humus, bio-fertilizer and nutrient rich water.
It uses the ability of the earthworms and
beneficial microbes to break down organic waste
present in the wastewater and transform it into
worm-cast.
How Biofilter works?
•The key to the Absolute Water Biofilter
system is high efficiency and multi filter
medium which include worms, specially
developed microbes, organic and inorganic
media.
• Condensate is distributed evenly over the
surface of the filter medium, by sprinklers. As
the wastewater slowly percolates down,
naturally occurring microbes degrade the
solids and organic matter, reduce coli form
bacteria, and nitrify ammonium, producing
clear and odorless water.
•Earthworms act as media to host millions of
microorganisms, which help in rapid
degradation of the organic matter present in
the wastewater.
•Filtration through the inorganic media bed
removes the final traces of the suspended
solids in the water and is clean for direct
disposal on agricultural land.
21. TYPICAL USAGE OF RECOVERED WATER
IMBIBITION
BOLIER FEED
CONDENSER MAKE UP
COOLING TOWER MAKE UP
MILL BEARING COOLING
MILK OF LIME PREPARATION
DRINKING WATER PLANT FEED
