Disposing of waste in a landfill involves burying waste to dispose of it.
It is relatively cheap in countries where land is abundant
This is the most common & oldest practice in most of the countries
Landfill Problems & Precautions
Improper landfill procedures can lead to problems such as :
Litter Blowing Around & spreading
Attraction & proliferation of vermin & biotics leading to health hazards
Generation of liquid leachate .
Generation of gas such as methane and carbon dioxide creating odor problems & killing surface vegetation
Professionally Managed Landfill
A Professionally Managed Landfill site takes care of all the above mentioned problems & environmental dangers
There is strict regulation & control in the treatment & disposal of wastes
There is continuous monitoring of the effects of the waste even years after.
A view of a typical secured landfill cell
Compaction Process In a Landfill
Cross section of Bottom Liner
Cross section of Top Liner
Loading a Landfill
Wheel Wash Area
Incineration is a disposal method that involves combustion of waste material.
Incinerators convert waste materials into
Steam (from the moisture in wastes)
Ash (final residue of wastes)
It is a practical method of disposing of certain hazardous waste materials (such as biological medical waste)
Incineration is common in countries such as Japan where land is more scarce, as these facilities generally do not require as much area as landfills
processing used materials
Generation of new products
It is useful for the foll :
It prevents the waste of useful materials
It reduce the consumption of fresh raw materials
It reduce energy usage
It reduces air & water pollution
Type of Recycling
Segregation of plastics, glass, paper, alum cans etc.
Compost generation usiing vermin
Anaerobic industrial treatment plants
Using simple crushing & melting process
Using complex chamical processes
Generation of heat by burning (used as fuels)
Generation of diesel from waste plastics
Conditions for Economic viability of Recycling
An adequate & stable source of recyclates
An cost effective system to extract those recyclates from the waste stream
A factory capable of reprocessing the recyclates very near the source
A demand for the recycled products
Concrete & Construction rubble : is put through a crushing machine, often along with asphalt, bricks, dirt, and rocks. Smaller pieces of concrete are used as gravel for new construction projects.
Batteries : The large variation in size and type of batteries makes their recycling extremely difficult: they must first be sorted into similar kinds and each kind requires an individual recycling process
They contain mercury and cadmium , harmful materials which must be handled with care
Lead-acid batteries are relatively easy to recycle
Biodegradable waste : Kitchen, garden and other green waste can be recycled into useful material by composting. This process allows natural aerobic bacteria to break down the waste into fertile topsoil
E-Waste : Electronic waste recycling is done by mechanically separating the metals, plastics and circuit boards contained in the appliance
When this is done on a large scale at an electronic waste recycling plant, component recovery can be achieved in a cost-effective manner.
Ferrous metals : Iron and steel are the world's most recycled materials, and among the easiest materials to reprocess, as they can be separated magnetically from the waste stream.
Scrap is either remelted in an electric arc furnace (90-100% scrap), or used as part of the charge in a Basic Oxygen Furnace (around 25% scrap)
Non-ferrous metals : Aluminium is one of the most efficient and widely-recycled materials.
It is made into small pieces & melted to produce molten aluminium.
The recycled aluminium is indistinguishable from virgin aluminium.
It can be recycled indefinitely.
Glass: It is crushed and added to a raw material mix in a melting furnace. It is then mechanically blown or molded into new jars or bottles .
It can be recycled indefinitely as its structure does not deteriorate when reprocessed.
Paper : It can be recycled by reducing it to pulp and combing it with pulp from newly harvested wood.
As the recycling process causes the paper fibres to breakdown, each time paper is recycled its quality decreases.
Plastic : Compared to glass or metallic materials, plastic poses unique challenges due to the number of types of plastic & must be sorted manually before they can be recycled
Waste to Energy Conversion- Thermal technologies
Gasification: It produces combustible gas, hydrogen, synthetic fuels
Thermal depolymerization: produces synthetic crude oil, which can be further refined
Pyrolysis: Produces combustible tar
Waste to Energy Conversion- Thermal technologies
Plasma arc gasification: It produces rich syngas including Hydrogen and Carbon Monoxide usable for fuel cells or generating electricity, useable vitrified silicate and metal ingots, & sulphur
Gasplasma: A process of gasification of shreaded waste to syngases, plasma arc treatment of syngas and syngas cleaning and conditioning. Syngas, Hydrogen, Carbon monoxide and CHP are the outputs. Residuals to landfill is less than 1%.
Waste to Energy Conversion- NonThermal technologies
Anaerobic digestion: It produces Biogas rich on methane
Mechanical biological treatment
MBT + Anaerobic digestion or Advanced MBT AMBT
MBT to Refuse derived fuel
European Waste Management Scenario
Gujarat Enviro Protection & Infrastructure Ltd.
Typical Layout of an integrated waste management Company