SUSTAINABLE UTILISATION
OF SPENT WASH IN
AGRICULTURE – A CASE FOR
OTCLA
by:
Dr. Yashpal SinghEnvironmental Counselor
THE HIDDEN WEALTH
Currently about 45 billion liters of S.W. produced in
the country
Non Toxic, contains plant nutrients.
Bio methanated waste water can produce 85000
tonnes of biomass annually
24500 Tons Potash (1.55 million hectare) Double
Cropping
12500 tons of Nitrogen (0.13 million hectare)
2100 Tons of Phosphorous (0.025 million hectare)
Also Zinc, Iron, Manganese, Organic Compounds,
Vitamins, Proteins, Growth promoters, biocides etc.
Treatment
• Starting from lagooning various technology
options evolve with consensus.
• Biomethanation
• Biomethanation and secondary treatment followed
by irrigation or disposal in inland surface waters
• One Time Controlled Land Application
• Composting with or without biomethanation
• Activated sludge treatment
• Concentration and incineration
• Anaerobic digestion followed by evaporation and
composting.
• Reverse Osmosis
• Recovery of potash
• Most of these technologies recognized as viable
technologies by the Regulatory bodies.
AIDA prays before NGT to allow mix of technology.
NGT agrees. Asks for guidelines on ZLD and Online
Water security a vital issue
Sugar Cane likely to suffer a loss of 30% in India
because of water. Climate change projections.
Effluents irrigation utilise the fertilization and
irrigation potential of waste.
Replaces chemical fertilizers. Provides essential
nutrients like NPK.
Saves recipient systems from pollution.
CPCB document recognizes aerobic composting,
vermi-culture, ferti irrigation and one time controlled
land application as emerging technologies.
Use of Waste Waters in Agriculture
45 billion litres
500 crores in terms of NPK and S
150 crores for micro nutrients and organics
100 crores saving in Environmental costs
100 crores in terms of loss to fisheries
500 crores savings in water treatment costs
100 crores in Public health
100 crores in Landscape costs
Energy savings in secondary and tertiary systems 1400 crores
In Gujarat, waste water supports annual agriculture production
worth Rs. 26.6 crores.
Economics
Increase yield 45 to 100%
Meets long term requirement of nutrients
Beneficial for soil flora/fauna
Conjunctive use preferred
Effect on crops
Impact on Ground Water
Continued use has not impacted ground water.
Need to be constantly monitored
Impact on Soil
Improved physical/chemical properties
Stable aggregates, moisture retention, water
holding, aeration
Improvement in soil carbon and potash
Post harvest soil not known to exhibit
adverse affects.
Chemical Properties
Increases pH, EC, Cations, Anions, SAR, KAR,
exchangeable K, Na, Ca and Mg, nitrogen
availability, soil nitrate, phosphorous.
Damaging impacts at doses 300 m3/ha or lower not
observed
Biological Properties
Improves biological activity
Higher counts of bacteria, Actinonomycetes,
Azetobacter and Fungi.
Colour of effluent degrades
Growth promoting substances GA/IAA reported
Incidence of plant pests decreases
Emergent technology
20 to 60% increase in yield. Upto 200 m3/ha twice a year.
Increases soil fertility
Some states following practice
CPCB feels it is difficult to manage
Regulatory authorities do not permit
Presown Land Application
CPCB and Technology Options
Recommends use in Agriculture through CREP
Recognizes these as emerging technologies
Recognizes use of effluents in agriculture in guidelines
Industry allowed to practice any technology
Standards still allow disposal in water or on land.
Discourages use of these technologies in May 2008.
Professes co-processing
Initiates study on utilisation in Agriculture in 2007-2008.
Report awaited.
Principal Scientific Advisor to Government of India brings out
report in 2015 on Green Chemistry initiatives. Supports
agriculture utilisation.
Incineration not regarded viable by CPCB.
Co-processing is not viable with only, Cement and 11 TPP’s.
Can take care of only 24/50 KLD of spent wash in a Cement
plant of 3000 TPD.
Involves change in Kiln design and special APCS.
Evaporation and ZLD likely to affect minimum flows
Self Cleansing capacities
May trigger drying up of rivers due to reverse recharge
Irrigation Water availability
Availability of water for competing uses
Promote Increased use of Chemical fertilisers
Increased generation of power
May 2008 minutes recommend change to incineration only if
existing standards are not being met
Introduction of ZLD likely to introduce ecological
consequences
May need an environmental Assessment and E.C.
Land application the most efficient means of recycling water
and nutrients.
Needs efficient irrigation management plan and regulated use
in rainy season.
National Water Quality Management
Strategy for Australian Wineries and
Distilleries recognizes-
CSR Distilleries, Victoria
Two main product streams, Ethanol and fertilizers
Bio dunder blended with Nitrogen, Phosphorous, Sulphuric
acid to give Liquid one shot.
Bottled and sold, crop specific constitution
Certified as organic and granted Beneficial use status by EPA.
Beneficial to soils and crops.
Distillery converts from a Pariah to a welcome
industry
Change in process technology to bio-still resulted in
reduced steam (by 30%) and water consumption (by
70%)
Improved plant productivity, product quality
Turned Pollutant into saleable product . 100% of
spent wash is being recycled in this market.
Ended complaints. Instead of closing, Industry
thrives.
CSR employees given the Annual Environment
Award by the Australian Chemical Industry Council
in 1992.
Bureau of Sugar Experimental stations assisted by
conducting field trials and determining optimum
rates.
CSR Distilleries (Contd)
BRAZIL
Land application the most efficient means of recycling water
and nutrients.
Vinasse BOD 75330, COD 97400, TDS 33680, NPK of
885:188:3852 mg/L
Fully recycled to the fields for ferti-irrigation
Mills have applied vinasse to 70% of their crop areas
Tanks, Trucks and Sprinklers
No damaging impacts on soil at doses lower than 300 m3/ha
Doses in excess of 400 m3/ha could be harmful
Considered as an organic fertilizer and released for organic
Sugar production
A technical Standard by the Office of Secretary of
Environment (Sao Paulo) regulates application eg. Risk areas,
permitted doses and technology.
Ferti irrigation program 1996
35% Federal Funds, 15% State Funds and 50%
project beneficiaries
Covers Ferti-irrigation equipments and technology
assistance.
40% Water, 32% energy costs reduction achieved.
18% harvested area, 30% production, 28%
exportable farm produce increments
IRR of 16% including all costs and 25% return in
farmers investment.
Mexico
MEXICO and other Countries
Other Countries
In Romania, Vinasse is applied to permanent grass lands at
4 to 7 tonne/ha in a 1:5 water dilution. Yield increased upto
81% over control.
Improved nutritive value of fodder.
In Ireland slops are concentrated in MEE and processed to
Pot Ale for agricultural use.
Spent wash is rich in nutrients and good for crops
and soils. Efforts should be made to fruitfully utilise
the spent wash for agricultural applications.
Controlled land application of BMSW may be
beneficial for reclamation of sodic soil.
Presowing application of BMSW followed by two
irrigations can leach out soluble salts from surface
soil for better germination and growth
Report recommends long term comprehensive
research projects on aspects of doses, soil types,
permeability etc.
Information should be collected on international
practices.
Green Chemistry Initiatives
On Incinerator
BMSW rich in potash and wasting nutrients not desirable
Country depends on import of Potash
Recovery of Potash from SW by evaporation and incineration
would not be viable.
Even after incineration, the safe disposal of ash generated
with high concentration of inorganic salts is a problem
Before insisting on incineration there is a need to evaluate
system.
Green Chemistry Initiatives
Use BMSW only
BOD not to exceed 7000 mg/L, pH not more than 7
30 days storage during monsoon
Command area within 20 kms
Use either pipeline or tanker
Sampling and monitoring
Detailed utilisation plan
Apply uniformly on land 20 days prior to sowing and
ploughed before raising the crop.
Dosage defined
Soil pH not to exceed 8.5 and ECe 4 millimhos/cm
Increase in BOD, TDS and No3 not more than 3
mg/L and 10 mg/L.
Install piezometers
MOU with University
OTCLA Protocol
Acidic Raw Spent Wash could be utilised
300 Kl/ha recommended for soils beyond 8.5 pH. Equivalent
to 34.40 tonnes/ha of Gypsum
Untreated spent wash should not be used for a pH of less
than 8.5
Distillery SW alone or in combination with gypsum is effective
Time log of one month between raw spent wash application
and sowing next crop
BMSW is not effective in reclaiming calcareous soils
Sodic Soil Reclamation
THANK YOU