NSTP 2 - Module NSTP 2 - Module

III. Learning Contents:

NATIONAL
SERVICE METHODS OF DISPOSAL
TRAINING
Solid Waste Disposal 1. Landfill
PROGRAM Disposing of waste in a landfill involves burying the waste, and this remains a common practice in
most countries. Landfills were often established in abandoned or unused quarries, mining voids or
borrow pits. A properly designed and well-managed landfill can be
a hygienic and relatively inexpensive method of disposing of waste
materials. Older, poorly designed or poorly managed landfills can
create a number of adverse environmental impacts such as wind-
I. Introduction: blown litter, attraction of vermin, and generation of liquid leachate.
Another common byproduct of landfills is gas (mostly composed
Currently, we are facing a lot of environmental dilemmas such as global warming, flash floods and of methane and carbon dioxide), which is produced as organic waste
etc. We can ask what are the causes of these problems? What are the ways we need to address breaks down an aerobically. This gas can create odor problems, kill
them? surface vegetation, and is a greenhouse gas.
Design characteristics of a modern landfill include methods to contain leachate such as clay or
Disposal of waste into the surrounding locality has to date been the usual practice with little plastic lining material. Deposited waste is normally compacted to increase its density and stability,
concern for the environment. The misbehavior of the people towards waste disposal is one of the and covered to prevent attracting vermin (such as mice or rats). Many landfills also have landfill gas
causes of the problem. Some people are reckless in throwing their garbage. They do not think of extraction systems installed to extract the landfill gas. Gas is pumped out of the landfill using
the possible results of their actions on the environment. Every individual should take the perforated pipes and flared off or burnt in a gas engine to generate electricity.
responsibility of managing their wastes properly.

Public awareness campaigns are essential tools for environment protection. Thus, there is really a SANITARY LANDFILL
need to encourage the people to be part of this objective, protecting our environment through
Advantages: Disadvantages:
proper waste disposal.
Ø Low cost and ease of application, no Ø Leakage of air pollutant gases:
Waste has to be managed properly to preserve the planet for the coming generations. high-tech. methane, carbon dioxide.
Ø Absorb massive amounts of solid Ø Possibility of contamination of water
II. Objectives: wastes. sources by waste water resulting from
Ø Replanting the area with trees. landfill.
Ø Access to methane. Ø Requires proper planning, design and
A. Identify the different methods of solid waste disposal. Ø Filled land can be reused for other operation.
B. Understand what waste is and how it affects our environment. community purposes.
C. Learn ways to apply the 3R’s to their everyday life at school at home and in the
community.

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2. Incineration The most common consumer products recycled include aluminum such as beverage cans, copper
Incineration is a disposal method in which solid organic wastes are subjected to combustion so as such as wire, steel food and aerosol cans, old steel furnishings or equipment , polyethylene and
to convert them into residue and gaseous products. This method is useful for disposal of residue of PET bottles, glass bottles and jars, paperboard cartons, newspapers, magazines and light paper,
both solid waste management and solid residue from waste water management. This process and corrugated fiberboard boxes.
reduces the volumes of solid waste to 20 to 30 percent of the original PVC, LDPE, PP, and PS (see resin identification code) are also
volume. Incineration and other high temperature waste treatment recyclable. These items are usually composed of a single
systems are sometimes described as "thermal treatment". Incinerators type of material, making them relatively easy to recycle into
convert waste materials into heat, gas, steam and ash. new products. The recycling of complex products (such as
Incineration is carried out both on a small scale by individuals and on a computers and electronic equipment) is more difficult, due
large scale by industry. It is used to dispose of solid, liquid and gaseous to the additional dismantling and separation required.
waste. It is recognized as a practical method of disposing of The type of recycling material accepted varies by city and
certain hazardous waste materials (such as biological medical waste). country. Each city and country has different recycling programs in place that can handle the various
Incineration is a controversial method of waste disposal, due to issues such as emission of types of recyclable materials.
gaseous pollutants. 4. Sustainability
Incineration is common in countries such as Japan where land is scarcer, as these facilities generally The management of waste is a key component in a business' ability
do not require as much area as landfills. Waste-to-energy (WtE) or energy-from-waste (EfW) is to maintaining ISO14001 accreditation. Companies are encouraged
broad terms for facilities that burn waste in a furnace or boiler to generate heat, steam or to improve their environmental efficiency each year. One way to do
electricity. Combustion in an incinerator is not always perfect and there have been concerns about this is by improving a company’s waste management with a new
pollutants in gaseous emissions from incinerator stacks. Particular concern has focused on some recycling service. (such as recycling: glass, food waste, paper and
very persistent organics such as dioxins, furans, PAHs which may be created which may have serious cardboard, plastic bottles etc.)
environmental consequences.
5. Biological reprocessing
INCINERATION
Waste materials that are organic in nature, such as plant material, food scraps, and paper products,
Advantages: Disadvantages:
Ø requires minimum land Ø expensive to build and operate
can be recycled using biological composting and digestion processes to decompose the organic
Ø can be operated in any weather Ø high energy requirement matter. The resulting organic material is then recycled as mulch or compost for agricultural or
Ø produces stable odor-free residue Ø requires skilled personnel and landscaping purposes. In addition, waste gas from the process (such as methane) can be captured
Ø refuse volume is reduced by half continuous maintenance and used for generating electricity and heat (CHP/cogeneration) maximizing efficiency. The
Ø unsightly - smell, waste, vermin intention of biological processing in waste management is to control and accelerate the natural
process of decomposition of organic matter.
There is a large variety of composting and digestion methods and technologies varying in
3. Recycling complexity from simple home compost heaps, to small town scale batch digesters, industrial-scale
enclosed-vessel digestion of mixed domestic waste (see Mechanical biological treatment). Methods
Recycling refers to the collection and reuse of waste materials such as empty beverage containers.
of biological decomposition are differentiated as being aerobic or anaerobic methods, though
The materials from which the items are made can be reprocessed into new products. Material for
hybrids of the two methods also exist.
recycling may be collected separately from general waste using dedicated bins and collection
vehicles, or sorted directly from mixed waste streams.

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7. Resource Recovery
Anaerobic digestion of the organic fraction of MSW Resource recovery (as opposed to waste management) uses LCA (life cycle analysis) attempts to
Municipal Solid Waste has been found to be in a number offer alternatives to waste management. For mixed MSW
of LCA analysis studies to be more environmentally (Municipal Solid Waste) a number of broad studies have indicated
effective, than landfill and incineration. The resulting that administration, source separation and collection followed by
biogas (methane) though must be used for cogeneration reuse and recycling of the non-organic fraction and energy and
(electricity and heat preferably on or close to the site of compost/fertilizer production of the organic waste fraction via
production) and can be used with a little upgrading in gas anaerobic digestion to be the favored path.
combustion engines or turbines. With further upgrading
to synthetic natural gas it can be injected into the natural
gas network or further refined to hydrogen for use in
stationary cogeneration fuel cells. Its use in fuel cells 8. Avoidance and reduction methods
eliminates the pollution from products of combustion. An important method of waste management is the prevention of waste material being created,
also known as waste reduction. Methods of avoidance include reuse of second-hand products,
An example of waste management through composting is
repairing broken items instead of buying new, designing products to be refillable or reusable (such
the Green Bin Program in Toronto, Canada, where Source Separated Organics (such as kitchen
as cotton instead of plastic shopping bags), encouraging consumers to avoid using disposable
scraps and plant cuttings) are collected in a dedicated container and then composted.
products (such as disposable cutlery), removing any food/liquid remains from cans, packaging,
6. Energy recovery ... and designing products that use less material to achieve the same purpose (for example, light
The energy content of waste products can be harnessed directly by using them as a direct weighting of beverage cans).
combustion fuel, or indirectly by processing them into another type of fuel. Thermal treatment
ranges from using waste as a fuel source for cooking or heating
IV. Guide Questions:
and the use of the gas fuel (see above), to fuel for boilers to
generate steam and electricity in
a turbine. Pyrolysis and gasification are two related forms of Ø What are the methods of disposal?
thermal treatment where waste materials are heated to high Ø What is landfill?
temperatures with limited oxygen availability. The process Ø What are advantages and disadvantages of the landfill?
usually occurs in a sealed vessel under high pressure. Pyrolysis of Ø What is incineration?
solid waste converts the material into solid, liquid and gas products. The liquid and gas can be burnt Ø What are the advantages and disadvantages of incineration?
to produce energy or refined into other chemical products (chemical refinery). The solid residue
Ø What is recycling?
(char) can be further refined into products such as activated carbon. Gasification and
advanced Plasma arc gasification are used to convert organic materials directly into a synthetic gas Ø What is biological reprocessing?
(syngas) composed of carbon monoxide and hydrogen. The gas is then burnt to produce electricity Ø What resource recovery?
and steam. An alternative to pyrolysis is high temperature and pressure supercritical water Ø What is avoidance and reduction method?
decomposition.
V. Learning Activities:

A. Essay

• Explain briefly the given questions in the worksheets. Five (5) points each.
• Your essay will be graded based on the Essay Rubrics.

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