Please enable JavaScript.
Coggle requires JavaScript to display documents.
CHAPTER 8 : LANDFILL AND LANDFILL DESIGN, ODOR CONTROL - Coggle Diagram
CHAPTER 8 : LANDFILL AND LANDFILL DESIGN
INTRODUCTION
Waste Land Disposal
Attenuate and disperse sites (dumping site)
traditional
dilution and dispersion
Impossible to monitor
Containment sites (landfill)
isolated
natural clay bottom
liners or synthetic liners
Facilities for leachate and gas
collection
Types of Landfill
Conventional LF for commingled MSW
native soil is used
non-hazardous industrial waste and
sludge from water and wastewater treatment plants
for milled solid wastes
can be placed at up to 35% greater density and
some without daily cover
Less soil cover
needs of shredding facilities, special section
expensive
material not readily available and low
precipitation
can produce compost
Monofills for designated or specialized wastes
Combustion ash and asbestos
odor problem due to reduction
of sulfate
Other types
to maximize gas production
as integrated treatment units
Terms of definition
Sanitary landfill
a method of disposing solid waste on land without
creating nuisance or hazard to public health or safety
Leachate
liquid from percolation of precipitation, uncontrolled
runoff, irrigation water, infiltrating groundwater and water
Landfill gas
mixture of gas produced from anaerobic digestion of
waste
Landfill liner
several layers of compacted clay and/or
geomembrane material (natural or synthetic)
use to line the bottom
area and below-grade sides of a landfill designed
to prevent
migration of leachate and gas
Landfill control facilities
liners, landfill leachate and
landfill gas collection and extraction systems
daily and final cover
layers
Environmental monitoring
activities associated with
collection and analysis of water and air samples
to monitor the
movement of LFG and leachate
Landfill closure
steps to be taken to close and secure and landfill
Postclosure
ctivities associated with the long-term
monitoring and maintenance of the completed landfill (30-50 years)
Landfill in Malaysia
approximately 230 landfills
Types
Hazardous Waste Landfill
Inert Waste Landfill
Open Dumping Landfill
Sanitary landfill
Level of Landfills
LEVEL 1
Controlled tipping
LEVEL 2
with a bund and daily soil
covering
LEVEL 3
with leachate re-circulation
system
LEVEL 4
with leachate treatment system
LANDFILL PLANNING DESIGN PRINCIPLE
Environmental monitoring
FACILITIES
Surface water drainage facilities
to develop an overall drainage plan for the area
shows location of storm drains, culverts, ditches and subsurface drains
depends on
location and configuration of LF
capacity of
natural drainage courses
Environmental monitoring facilities
Required for
Gases and liquids in the vadose zone
Groundwater quality both upstream and downstream of landfill sites
Air quality at boundary of LF and from any processing facilities
Specific number depends on
the configuration and size of LF
the requirements of the local air
and water pollution control agencies
Typical landfill progression
internal
interim
final slopes
exist when the final grades for a facility
have been achieved
interfaces never be loaded with more than 1,440 pounds/ft2
facility bottom
base of a facility that is usually sloping 5% or less
excludes internal slopes or
interim slopes
Reactions occurring in landfill
Chemical oxidation of waste materials
Escape of gases from the fill
Movement of liquids caused by differential heads
Dissolution and leaching of organic and inorganic materials by water and
leachate moving through the fill
Movement of dissolved material by concentration gradients and osmosis
Uneven settlement caused by consolidation of material into voids
Biological decay of organic materials
LANDFILL OPERATIONS & MANAGEMENT
Landfill operation
FACTORS
Stability analyses of the waste body
Waste placement techniques, phasing and
supervision
Settlement and other types of deformation, checked
by monitoring programme
Operating facility, buildings and roads
Gas management and monitoring programmes
Surface water and drainage
Leachate management and groundwater control
Environmental concerns
Covering Operations
after or concurrently
with tipping & compaction operations
To protect the full range of
environmental
TYPES
Daily
after tipping
Intermediate
reducing leachate
No dump more than 10 m
Final
cell is full
minimum cover 60 cm
FINAL COVER PLAN
To provide permanent isolation of the cells from rainwater
by encapsulation
To integrate the site into the environment
To guarantee a long-term future compatible with the
presence of waste
To allow easy management after operation
Provides a barrier to the migration of water into the waste
controls emissions to water and atmosphere
promotes sound land management and prevents hazards
LANDFILL SITTING CONSIDERATIONS
Site Construction
Requirements
Location
Capacity of the waste
Operations
Costs
Stability
Protection of soil and water
Factors
Available land area
Haul distance
Soil conditions and
topography
Surface water hydrology
Geologic and hydrogeology
conditions
Climatologic conditions
Local environmental
conditions
Ultimate use of site
PHASES
Phase 3
: Site investigation
Phase 2
: Identification of site areas (positive areas)
General data, e.g. volume, distance from main waste sources
Hydro-geology and water management
Goetechnical and constructional aspects
Meteorological aspects
Nature protection and land use
Phase 1
: Site rating process (negative mapping)
Drinking water
High flood areas
Unstable ground
Extreme morphology
Unsuitable geological and hydrogeological conditions
Residential areas
Nature protection areas
cultural sites
Phase 4
: Final decision
LANDFILL LAYOUTS AND DESIGN
Methods of Landfilling
Canyon/Depression method
Area Method
Excavated/ trench method
Ramp method
Factors to be considered
Protection of components already constructed
Minimum dimensions required for construction
work in particular, sealing layers and drainage
Simple and non-sensitive design and construction
Simple and non-sensitive
Climate conditions
Availability of construction materials
CONSTRUCTION PHASES
PHASE 1: Excavate land
PHASE 2 : Add compacted clay layer or synthetic layer
PHASE 3 : Install leachate collection system
PHASE 4: Install geosynthetic liner
PHASE 5 : Add a sloped, sand drainage layer
PHASE 6 : Deposit solid waste (open and use landfills)
PHASE 7 : Install groundwater and gas monitoring wells
PHASE 8 : Add soil layer
PHASE 9 : Install clay cap
PHASES 10 : Install geosynthetic cap
PHASE 11 : Install sand drainage layer
PHASE 12 : Add a layer of top soil
PHASE 13 : Plant grass and other short rooted plants
PHASE 14 : Construct methane recovery buldings
LANDFILL DESIGN
Filling
design
Drainage design
Leachate collection and gas collection
Liner design
Foundation design
Landfill design
Closure design
Run off collection
Selection of gas control facilities
New landfills
Quantity of LFG must first be estimated
Several rate should be analyzed
Horizontal or vertical gas recovery well
LEACHATE MANAGEMENT
LEACHATE TREATMENT
TREATMENT TECHNOLOGIES
Biological Processes
Aerobic treatment processes
Anaerobic treatment processes
Leachate Transfer
Leachate Recirculation
Constructed Wetlands
Co-Treatment with Municipal Sewage
Physicochemical Processes
Flocculation-Coagulation
Separation through Membrane Filtration
Air Stripping
Adsorption by Activated Carbon
Chemical Precipitation
Ion Exchange
Chemical Oxidation and Advanced Oxidation Processes
Factors to Consider
On-site treatment and discharge
off-site treatment
Transport and treatment off-site
Leachate composition, properties, and volume
Need for leachate storage
Local water standards requirement for discharge
Technical value, ease of implementation, and cost effectiveness of technologies
ON-SITE TREATMENT
Purpose
Minimize the contaminants
Reduce high concentrations of COD & BOD
Removal of 90% COD and ammonia
Methods
Aerobic treatment (aerated lagoon)
Polishing treatment (reed bed)
Wetland system
Spray irrigation (evaporation)
Advantages
Lowest cost
Prevents public disturbances
Fertilizer
habitat for wildlife
Accommodate the changes in leachate
quality and quantity
Definition
Leachate
: A
contaminated liquid
that is generated from fluid percolating through the landfill and the liquid presence in the waste and from outside water.
LEACHATE FORMATION
Depends on
water availability
(e.g. precipitation, surface water, leachate recirculation)
characteristics of final cover
(soil and vegetation type, impermeable cover, slope)
characteristics of waste
(moisture content, density)
Composition
Chemical oxygen demand
Total suspended solid
Total organic carbon
Organic and ammonia nitrogen
BOD5
Total phosphorous and orthophosphorous
Alkalinity, pH, total hardness
Calcium, magnesium, sodium, sulphate and iron
Process
biological, physical and chemical events occur
Biological decay of organic materials, either aerobically or anaerobically with the evolution of gases and liquid
Chemical oxidation of waste materials
Dissolving and leaching of organic and inorganic by water and leachate moving through the fills
Movement of dissolved material by concentration gradients and osmosis
Factors
Climatic & Hydrogeologic
Rainfall, snowmelt, groundwater intrusion
Site Operations & Management
Refuse pretreatment, compaction
Vegetation, cover, sidewalls & liner material
Irrigation, recirculation, liquid waste co-disposal
Refuse Characteristics
Waste composition and the age of waste
Moisture content of waste
Degree of decomposition
Rate of water movement
Internal processes
LEACHATE COLLECTION
The process of leachate collection
To collect leachate, perforated pipes run throughout the landfill
These pipes then drain into a leachate pipe :- carries leachate to a leachate collection pond.
Leachate can be pumped to the collection pond or flow to it by gravity
The leachate in the pond is tested for acceptable levels of various chemicals
After testing, the leachate must be treated like any other sewage :- on-site or off-site.
Then, it can be release to river
LANDFILL GAS MANAGEMENT
Gas Formation
Composition
Methane : 45% to 60%
Carbon Dioxide : 40% to 60%
nonmethane organic compounds (NMOCs) (trichloroethylene, benzene, and vinyl chloride)
Oxygen
Ammonia
Sulfides
Hydrogen
Carbon Monoxide
Phases
Phase I
Aerobic bacteria consume oxygen while breaking down the long molecular chains of complex carbohydrates, proteins, and lipids
Phase II
Anaerobic bacteria convert compounds into acetic, lactic, and formic acids and alcohols
Phase III
Certain anaerobic bacteria consume the organic acids produced and form acetate, an organic acid
Phase IV
Composition and production rates of landfill gas remain relatively constant.
How is landfill gas produced?
Bacterial decomposition
Volatilization
Chemical reactions.
How does landfill gas move?
Diffusion (concentration)
Move from areas of high gas concentrations to areas with lower gas concentrations.
Pressure
Moving from areas of high pressure to areas of low pressure.
Permeability
Move through areas of high permeability (e.g., areas of sand or gravel) rather than through areas of low permeability (e.g., areas of clay or silt).
Landfill covers are often made of low-permeability soils therefore more likely to move horizontally .
Definition
Landfill Gas
: A complex
different natural gasses
produce by microorganism during the decomposition of organic matter within a landfill.
Factors
Waste input rate
pH and temperature
Waste density
Site management strategies
Landfill Gas Collection
Passive System
Active System
pumped wells at maximum of
50 meter intervals around the site perimeter
requires inner ring
excess air is not drown
Landfill gas control
Technologies
Landfill Cover
Flaring
Venting through a Filter
Parameter to control
Gas Production
Gas Movement and Migration
changes in barometric pressure
changes in leachate level
changes in water table levels
Gas Monitoring
Landfill Gas Control Measures
Gas Utilization/Exploitation of energy
Direct use of gas
feasible to clean-up the gas
compress the remaining methane
Conversion to electricity
CLOSURE &
POSTCLOSURE
Development of long-term closure plan
Cover and landscape design
Control of LFG
Collection and treatment of leachate
Environmental monitoring systems
Post-closure care
Routine inspection
Infrastructure maintenance
Environmental monitoring systems
PLAN TO CONVERT
Green Areas
Recreation
Agriculture
Housing
ODOR CONTROL
Factors influencing odor
strength
Type of waste
Volume of potentially odorous material
Time required to unload and cover
Meteorological and topographic conditions
Size of working face
Time of day
Factors amount of odor
Nature and moisture content of the waste
Amount of oxygen present
Temperature inside the landfill
Type of waste present in the landfill
The age of the landfill
ODOR CONTROL SYSTEM
Eliminate the generation
Cover the waste
Collect the gas
Masking waste
Odors of gas
Hydrogen Sulfide
Ammonia