Download - Solid waste management
Solid wastes
Issues and Approach
Presented by
Santhosh kumar
GARBAGE CRISIS
REASONS
The rapid urbanization.
Neglect from authorities.
Public apathy towards solid waste
sector.
WHY ACTION IS REQUIRED ON WAR FOOTING ?
Municipal Solid Waste (Management and Handling) Rules 2000.
Municipal authorities in the country to implement proper Solid Waste Management System by December 2003
Spread of epidemics in various parts of the Country.
Opposition from the communities encircle the existing dump sites.
Litigations against various ULB s. Public awareness
OBJECTIVE OF THE REPORT
To discuss,
Present situation
Various methods available for treatment of solid wastes
Operational aspects of solid waste treatment systems
Requirements for an effective solid waste management (SWM) system.
Importance of Awareness and community level initiatives.
SOLID WASTE GENERATION IN
KERALA
Kerala generates approximately 3,000
tones of solid waste daily.
Only less than a half of this is removed
from the streets
Only a tiny portion is processed or
recycled.
Rest is simply dumped in water bodies or
at land-filling sites.
EFFECTS OF INDISCRIMINATE
DUMPING OF WASTE
Blockage of drainage channels contributing to flooding.
Spreading of diseases by different vectors like insects, rodents and birds.
Emissions of green house gas that contributes global warming effect. (Methane is 20 times more harmful than CO2 in this regard)
Contamination of surface and ground water through leachate.
Soil contamination through direct waste contact or leachate.
Air pollution by burning of wastes
EFFECTED PARTIES
All people in general
Urban poor and slum dwellers are the
most effected.
Wealthy residents avoid direct exposure of
garbage piles close to home and the
problems are shifted away from their
neighborhood to elsewhere.
The Ministry of Environment and Forest -Municipal Solid
Waste (Management and Handling) Rules 2000
Directives:
Prohibit littering on the streets
Ensuring storage of waste at source in two bins; one for biodegradable waste and another for recyclable material.
Primary collection of biodegradable and non-biodegradable waste from the door step on a day- to-day.
Street sweeping.
Abolition of open waste storage bins.
Transportation of waste in covered vehicles
Treatment of biodegradable waste using composting or waste to energy technologies.
Minimize the waste going to the land fill.
Immediate steps to be taken
Stop unscientific dumping of waste at landfill sites. For this; Construct treatment facilities with capacities to
handle the present quantity collected.
Segregate waste into biodegradable, recyclable and inert fractions and only inert (non biodegradable) shall be land filled
Public awareness campaign to reduce waste quantity.
Promote recycling culture.
LONG TERM GOALS
Meet the guidelines of Municipal Solid Waste
(Management and Handling) Rules 2000
Improve the collection system to achieve 100 %
collection and add treatment capacity to handle
the entire waste quantity
Encourage community participation is essential
for smooth and efficient operation of SWM
system
Requirements of an effective Solid waste
Management program
Knowledge on Quantity and Characteristics of Waste
Efficient Collection network with complete coverage
Proper transportation of Waste
Fully equipped and well maintained Treatment/Recycling
facilities
Proper Disposal of Waste at land fill sites
Effective network for recycling and marketing of products
from solid waste treatment
Public awareness and Community Participation
Financial sustainability
Solid waste treatment – Available
technologies in use now
Composting
Vermicomposting
Anaerobic digestion / Biomethanation
Incineration
Gasification and pyrolysis
Plasma pyrolysis
Production of Refuse Derived Fuel (RDF) also known as pelletization and
Sanitary land filling/landfill gas recovery.
Conversion to bio-diesel
TREATMENT PROCESSES AN OVERVIEW
Biological Processes
Composting
Vermicomposting
Anaerobic digestion
Engineered Natural Process
Simple process and less capital
intensive
Minimum fuel (energy)
requirement
Complex process with high level
mechanization
High initial investment and
operation cost.
High energy input required
Physical Processes
Incineration
Chemical Processes
Gasification and pyrolysis
Plasma pyrolysis
Pelletization
BIOLOGICAL PROCESSES
Decomposition of Organic material by Microorganisms.
Two Types of process
1.Aerobic Process - By organism which requires oxygen
for respiration
Example - Composting
Organic Matter + O2 CO2 + H20 + New Cells (growth)
Complete Oxidation of Organic matters takes place
2.Anaerobic process – By organism which does not require
oxygen for respiration
Example – Anaerobic Digestion (Biogas plant)
Organic Matter CO2 + CH4 + H2S+ NH3 New Cells (growth)
Incomplete Oxidation of Organic matters resulting in formation of methane which on further oxidation acts as a fuel.
Composting
Composting is the most simple and a cost effective technology for treating the organic fraction of MSW
It is a well known process used by farmers since times immemorial.
Compost made out of urban heterogeneous waste is of higher nutrient value compared to the compost made out of cow dung and agro-waste.
It is a process in which organic material undergo biological degradation to a stable end product.
Microorganisms such as bacteria and fungi account for most of the decomposition.
Composting Process
Two Types of Composting Process
Windrow Composting
Box Composting
Allow passage of air and action of microorganisms for 6-7 weeks.
Garbage decomposes into stable end products
Heap the garbage in the form of windrows
Fill garbage in the boxes with holes for air entry
Comparison of Windrow & Box
composting
Particulars Windrow Composting Box Composting
Space
requirement
More space required Less space
requirement
Capital cost Less initial cost due to
lower infrastructural
requirements
Initial capital cost is
high
Operational
Manpower
requirement
Manpower required for
turning of Windrows
Requires less
manpower than
windrow composting
Operation of Composting Facility
Sorting
Mixing
Piling as windrows or filling in the box
Turning of Windrows (Not applicable for box composting)
Temperature Control
Moisture control
Maturing/ Curing
Screening
Storage and bagging
Vermicomposting
Worm composting is the process of culturing
worms to decompose organic waste.
This can be done indoors and outdoors, thus
allowing year round composting
Suitable for apartment dwellers also
Compost is made in a container filled with
moistened bedding and redworms.
vermi-composting is the preferred method at
house hold level and for small communities
Anaerobic Digestion or
Biomethanation
Biomethnation or Anaerobic Digestion (AD) is a the most commonly
used method of ‘Waste to Energy’ conversion
Solid waste with large proportion of organic matter is subjected to
decomposition in anaerobic condition, it produces a gaseous
mixture of CH4 (50- 60 %) and CO2.
This gas, known as bio-gas can be used for burning or for
generation of electricity.
The industrialization of AD began in 1859 with the first plant in
Bombay.
China and India are the front runner in popularizing this technology
for agro base small scale biogas plants
Now US & European Nations have acknowledged the importance of
Biogas as a source of Renewable energy.
Anaerobic Digestion Process
Steps of Digestion process • Hydrolysis • Acidogenesis • Acetogenesis • Methenogenesis
C6H12O6 → 3CO2 + 3CH4
General Process Description
Generally the overall AD process can be divided into four stages
Pretreatment
Sorting of waste and breaking into small pieces and adding required water
Waste digestion
Four step Process as explained in previous slide by Micro organisms.
Gas recovery
Gas generated collected and used as fuel
Residue treatment
The residue of Digestion (Digestate ) after dewatering can be used as Soil Conditioner like Compost
Process Diagram
Biogas
Anaerobic Digestion Process produce a much
valuable end product biogas compared to
composting process.
Initial investment and operating cost required for
anaerobic digestion plant for MSW is much higher
than that of Composting Plant.
Hence effective utilization of Biogas is very
important to make AD process financially atractive.
Biogas yield is up to 350 m3/ Ton of waste with a
calorific value of about 4000 kcal/m3
Electricity Generation from Biogas
About 100-150 kWh of Electricity can be generated per tone of waste input.
IC engines designed to burn propane or natural gas are easily converted to burn biogas by adjusting carburation and ignition systems
Two types of generators are used
Induction generators
Synchronous generators
Induction generators derive their phase, frequency and voltage from the utility
Synchronous generators operate as an isolated system or in parallel to the utility
Comparison of of Anaerobic Digestion
vs Composting
Particulars Anaerobic Digestion Composting
Space requirement
(footprint)
50% 100%
Emissions & Odours Low High (odours, Ammonia,
methane, nitrous oxide,
Hydrogen sulfide)
Energy balance Energy surplus Energy demand
Biogas production 100 – 150 m3/Mg Nil
Process time required
to produce mature
compost
3 weeks digestion, plus
5 weeks composting
12 weeks
Skilled Manpower Skilled manpower
required
Not required
Process upsets and
failure
Very strict monitoring
required operation.
Very rugged process
Hierarchy to be followed in Solid
Waste Management Program
Conclusions and Recommended
Options
Vermicomposting is preferred at individual house and small community level.
Composting is the simplest and cheapest method for medium level capacities.
It is the preferred process for panchayaths as it is less capital intensive and has less O&M requirements
Anaerobic digestion plants are suitable for large plants (Municipalities) as it requires less space.
A hybrid System comprising of Anaerobic Digestion Plant with Composting facility (for organic waste not easily digestible) will be a complete plant.
A effective network for marketing of Compost and recyclable items is very important.
In case of Power generation from biogas, the possibility of grid connection need to be studied.
THANK YOU