CHAPTER 5 Solid Waste

Definition

1. Biodegradable waste : - waste from preparation of cooking, serving food

market waste which is more on organic waste

2. Rubbish-waste from unwanted material after using e.g, old newspaper,plastic

bag.

Composition of solid waste

An ever-expanding population and high rates of economic development in Malaysia

resulted in the generation of vast amount of waste.

It is estimated about 17,000 of waste generated in Peninsular Malaysia. Generation

of waste average per capita is 0.85 kg/cap/day. About 1.5 kg/cap/day waste

generate in Kuala Lumpur.

Table 1: Solid Waste Composition of Selected Locations in Peninsular Malaysia (%)

Organic waste: kitchen waste, vegetables, flowers, leaves, fruits.

Toxic waste: old medicines, paints, chemicals, bulbs, spray cans, fertilizer and

pesticide containers, batteries, shoe polish.

Recyclable: paper, glass, metals, plastics.

Soiled: hospital waste such as cloth soiled with blood and other body fluids

Waste

Composition

Kuala Lumpur Shah Alam Petaling Jaya

Garbage 45.7 47.8 36.5

Plastic 9.0 14.0 16.4

Bottles/Glass 3.9 4.3 3.1

Paper/Cardboard 29.9 20.6 27.0

Metals 5.1 6.9 3.9

Fabric 2.1 2.4 3.1

Miscellaneous 4.3 4.0 10.0

Years K. L. Population Solid Waste Generated

(tones/day)

1998 1,446.803 2,257

Table 2: MSW Generated in Kuala Lumpur in 2002

Table 3: Sources and Types of Municipal Solid Waste

Sources Typical waste

generators Types of solid waste

Residential Single and multifamily

dwellings

Food wastes, paper, cardboard, plastics, textiles,

glass, metals, ashes, special wastes (bulky items,

consumer electronics, batteries, oil, tires) and

household hazardous wastes

Commercial

Stores, hotels,

restaurants, markets,

office buildings

Paper, cardboard, plastics, wood, food wastes,

glass, metals, special wastes, hazardous wastes

Institutional Schools, government

center, hospitals, prisons

Paper, cardboard, plastics, wood, food wastes,

glass, metals, special wastes, hazardous wastes

Municipal

services

Street cleaning,

landscaping, parks,

beaches, recreational

areas

Street sweepings, landscape and tree trimmings,

general wastes from parks, beaches, and other

recreational areas

Figure 1: Waste Generation in Selected ASEAN Countries (2001)

2000 1,787.000 3,070

2005 2,150.000 3,478

Role of Local Authority

1. Federal Government

Involved agency such as

1. Ministry of Housing & Local Government - is responsible for implementing all laws

pertaining to local government, the development of local government policy and the

implementation of all local government functions such as town and country planning,

housing, landscaping, solid waste management and fire and rescue services.

2. Economic Planning Unit, Prime Minister Department Implementing a solid waste

management program

3. Department of Environment monitor solid waste disposal and management to

control pollution

4. Ministry of Health- monitor solid waste disposal and management to control health

risk

State Government

Issue on land for site selection of landfills

Local Authorities

Local Authorities are the implementing agencies and have direct responsibility over solid

waste collection, treatment and disposal.

The three main laws governing local government in peninsular Malaysia are:

1. Local Government Act 1976 (Act 171)

2. Street, Drainage and Building Act 1973 (Act 133)

3. Town and Country Planning Act 1976 (Act 172).

Transfer Station

Transfer operations, in which the waste, containers, or collection vehicle bodies holding the

wastes are transferred from a collection vehicle to transfer or haul vehicle, are used

primarily for economic considerations.

Transfer operations may prove economical when

o Relatively small, manually loaded collection vehicles are used for that

collection of residential waste and long haul distances are involved

o Extremely large quantities of wastes must be hauled over long distances

o One transfer station can be used by a number of collection vehicles

Important factor that must be consider designing a transfer station include:

1. Type of transfer station

2. Transfer station capacity requirement

3. Equipment and accessory requirements

4. Environmental requirements

5. Health and safety

Type of transfer station:

If waste recovery is to be accomplished at the transfer station, then an adequate

area must be available for the collection vehicles to unload.

Transfer station capacity requirement

1. The throughput capacity of a transfer station must be such that the collection

vehicles do not have to wait too long to unload.

2. In most cases, it will not be cost-effective to design the station to handle the

ultimate peak number of hourly loads. Ideally, an economic trade-off analysis should

be made.

Equipment and accessories requirement

o The equipment and accessories used in conjunction with a transfer station

depends on the function of the transfer station in the waste management

system.

o The type and amounts of equipments required vary with the capacity of the

station.

o In a pit type storage-load transfer station, one or more tractors are required

to break up the wastes and to push them into the loading hopper.

o Additional equipment is required to distribute the waste and to equalize the

loads.

o In some installations an overhead clamshell crane has been used successfully

for both purposes.

o Scales should be provided at all medium and large-sized transfer station, both

to monitor the operation and to develop a meaningful management and

engineering data.

o Scales are also necessary when the transfer station is to be used by the public

and the charges are to be based on weight.

o If the transfer station is to be used as a dispatch centre or district

headquarters for a solid waste collection operation, more complete facility

should be constructed.

Environmental requirement

o Most of the modern, large transfer stations are enclosed and constructed with

materials that can be maintained and cleaned easily.

o To eliminate inadvertent emissions, enclosed facilities should have air-

handling equipment that creates a negative pressure within the facility.

o Fireproof construction material are used for direct-load transfer stations with

open loading areas.

o Special attention must be given to the problem of blowing papers.

o Regardless of the type of station, the design and construction should be such

that all areas where rubbish or paper can accumulate are eliminated.

o The best way to maintain overall sanitation of a transfer station is to monitor

the operation continuously.

o Spilled solid wastes should be picked up immediately or in any case should

not be allowed to accumulate for more that 1 or 2 hours.

o the area should also be washed down regularly.

o In some large facilities, waste water pretreatment facilities may be required

to treat plant waste water before it is discharged to the local sewer. In remote

areas, complete waste water treatment facilities may be required.

Health and Safety

o Health and safety issues at the transfer station are related to dust inhalation

and other OSHA requirements.

o Overhead water sprays are used to keep the dust down in the storage area of

a storage-load transfer station.

o To prevent dust inhalation, workers should wear dust masks.

o In storage-load transfer stations, tractors in the pit area should have enclosed

cabin equipped with air conditioning and dust filtering units.

o For safety reasons, the public should not be allowed to discharge wastes

directly into the pit a large storage-load transfer station.

Location

Transport station should be located :

o As near as possible to the weight centre of the individual solid waste production

areas to be served.

o Within easy access of major arterial highway routes as well as near secondary or

supplemental means of transportation.

o Where there will be a minimum public presence and operations will be most

economical.

Method

Motor Vehicle Transport

o Where the point of final disposition can be reached by motor vehicles, the most

common means used to transport solid wastes from transfer station are trailers,

semitrailers, and compactors.

o All the types of vehicles can be used in conjunction with either type of transfer

station.

o In general, vehicles used for hauling on high-ways should satisfy the following

requirements:

o Wastes must be transported at minimum cost.

o Wastes must be covered during the haul operation.

o Vehicles must be designed for highway traffic.

o Vehicle capacity must be such that the allowable weight limits are not

exceeded.

o Methods used for unloading must be simple and dependable.

Railroad Transport

o Although railroad were commonly used for the transport of solid wastes in the

past, they are now used by only a few communities.

o However, renewed interest is again developing in the use railroads for hauling

solid, waste, especially to remote landfill areas where highway travel is difficult

and railroad line now exist.

Water Transport

o Small Ship, boats, ferry, and special boats have been used in the past to transport

solid waste to processing locations and ocean disposal sites.

o One of the major problems encountered when ocean vessels are used for the

transport of solid wastes is that it is often impossible to move the barges and boats

during high tide.

o In such cases, the waste must be stored, entailing the construction of costly storage

facilities.

Type of transfer station

Direct-load transfer stations

At direct-load transfer stations, the wastes in the collection vehicles are emptied

directly into the vehicle to be used to transport them to a place of final disposition or

into facilities to compact the waste into waste transport vehicles into waste bares.

Storage-load transfer station

In the storage-load transfer station, wastes are emptied directly into a storage pit

from which they are loaded into transport vehicles by various types of auxiliary

equipment.

The difference between a direct-load and a storage-load transfer station is the latter

is designed with a capacity to store waste (typically 1-3 days).

Collection Routes

Collection routes must be laid out so that both the collectors and equipment are used

effectively.

Some heuristic guidelines that should be taken into consideration when laying out

routes are as follows:

o Existing regulations and frequency of collection must be identified

o Existing system characteristics such as crew size and vehicle types must be

coordinated.

o Where ever possible, routes should begin and end near streets, using

topographical and physical barriers as routes boundaries.

o In hilly area, routes should start at the top of grade and proceed downhill as

the vehicle becomes loaded.

o Routes should be laid out so that the last container to be collected on the

route is located nearest to the disposal site.

o Waste generated at traffic-congested locations should be collected as early in

the day as possible.

o Sources at which extremely large quantities of waste are generated should be

serviced during the first part of the day.

o Scattered pickup points, if possible be serviced during one trip or the same

day.

Landfill Sanitary

Landfill of mixed waste

Limited amount of non-hazardous industrial waste and sludge from water and waste

water sludge are accepted

To obtain additional landfill capacity, excavating the decomposed material to recover

the metals and using the decomposed residue as daily cover for the new waste.

In Some cases, the decomposed waste are excavated and stockpiled, and a liner is

installed before landfill is re-activated

Landfill of shredded solid waste

Shredded or milled waste can be placed at up to 35% percent grater in density that

un-shredded waste.

Because shredded waste can be compacted to a tighter and more uniform surface, a

reduce amount of soil cover or some other cover material may be sufficient to control

infiltration of water during the filling operation.

The shredded waste method has a potential application in areas where landfill

capacity is very expensive because of the greater compaction obtainable.

Landfill for individual waste constituent

Landfills for individual waste constituent are known as monofills

Combustion ash, and other similar waste are often identified as designated waste,

typically placed in monofills to isolate them from materials placed in municipal solid

waste landfills.

Because combustion ash contains small amount of unburned organic material, the

production of odours from reduction of sulphate has been a problem in monofills

used combustion ash.

Landfill methods

Excavated cell / trench methods

Is ideal for areas where an adequate depth of cover materials is available and water

table is not near to surface.

Solid waste placed in cell or trenches excavated in soil.

The soil excavated from the site used for daily and final cover.

Area methods

This method is used when the terrain is unsuitable for excavation of cells or trenches

in which to place the solid waste.

Site preparation includes the installation of a liner and leach control system.

Cover material must be hauled in by truck from adjacent land or borrow-pit areas.

Canyon / Depression Methods

Canyons, ravines, dry borrow and quarries have been use as landfills

The techniques to place and compact solid waste vary with the geometry of the site,

the type of leachate, gas control facilities an access site.

Control of surface drainage often is a critical factor in the development of this

methods.

Typically l, filling for each lift start at the head en of the canyon and ends at the

mouths

If the canyon floor is reasonably flat, the initial landfilling may be carried out using

the excavated cell / trench methods.

Factors that must be considered in evaluating potential sites for landfilling:

Haul distance

Location restriction

Available land area

Site access

Soil condition and topography

Climatologically condition

Surface water hydrology

Geologic and hydro-geological condition

Local environmental condition

Landfill Operating Schedule

Factors that must be considered in developing operating schedules include:

o arrival sequences of collection vehicles,

o traffic patterns at the site,

o the time sequence to be followed in the filling operations,

o effects of wind and other climatic conditions,

o commercial and public access

Solid Waste Filling Plan.

Once the general layout of the landfill site has been established, it will be necessary

to select the placement method to be used and to lay out and design the individual

solid waste cells.

The specific method of filling will depend on the characteristics of the site, such as

the amount of available cover material, the topography, and the local hydrology and

geology.

The filling sequence should be established so that the landfill operations are not

impeded by unusual weather or adverse conditions.

Landfill Operating Records

To determine the quantities of waste that are disposed, an entrance scale and a

gatehouse will be required.

The gatehouse would be used by personnel who are responsible for weighing the

incoming and outgoing trucks.

The sophistication of the weighing facilities will depend on the number of vehicles

that must be processed per hour and the size of the landfill operation.

Load Inspection for Hazardous Waste

Load inspection is the term used to describe the process of unloading the contents of

a collection vehicle near the working face or in some designated area, spreading the

wastes out in a thin layer, and visually inspecting the wastes to determine whether

any hazardous wastes are present.

The presence of radioactive wastes can be detected with a hand-held radiation

measuring device or at the weigh station, as described above.

If hazardous wastes are found, the waste collection company is responsible for

removing them.

Public Health and Safety

The health and safety of the workers at landfills is critical in the operation of a landfill.

The federal government through OSHA regulations and states through OSHA-type

programs have established requirements for a comprehensive health and safety

program for the workers at landfill sites.

Attention must be given to the types of protective clothing and boots, air-filtering

head gear, and puncture proof gloves supplied to the workers

Site Safety and Security

The increasing number of law suits over accidents at landfill sites has caused landfill

operators to improve security at landfill sites significantly.

Most sites now have restricted access and are fenced and posted, with no

trespassing and other warning signs.

In some locations, television cameras are used to monitor landfill operations and

landfill access.

Incineration

Waste incineration involves the application of combustion processes under controlled

conditions to convert waste materials to inert mineral ash and gases. The three Ts of

combustion (temperature, turbulence, and residence time) must be present along

with sufficient oxygen for the reaction to occur:

The burning mixture (air, wastes, and fuel) must be raised to a sufficient

temperature to destroy all organic components. The combustion airflow is reduced to

the minimum level needed to provide the oxygen for the support fuel (gas, oil, or

coal) and the combustible wastes without forming high levels of CO and unburned

hydrocarbons. This will raise the temperature to the level needed for good

combustion.

Turbulence refers to the constant mixing of fuel, waste, and oxygen.

Residence time is the time of exposure to combustion temperatures.

Oxygen must be available in the combustion zone.

Types of Incinerators

Waste incinerators are used to destroy solids, sludges, liquids, and tars. Depending

upon the physical, chemical characteristics of the waste and the handling they

require, different incinerator designs will be applied.

Solids, sludges, and tars are incinerated in fixed-hearth and rotary kiln incinerators.

Liquids may also be burned in these systems and used as support fuel.

In many plants where liquids are the primary wastes, liquid injection incinerators are

used.

Boilers, process furnaces, cement kilns, and lightweight aggregate kilns also utilize

the energy available from liquid wastes and burn liquid wastes as well as the fossil

fuels (natural gas and oil).

Fixed-Hearth Incinerators.

Fixed-hearth incinerators are used extensively for medical and municipal waste

incineration. Fixed hearths can handle bulk solids and liquids.

A controlled flow of "underfire" combustion air (70 to 80 percent of the theoretical air

required) is introduced up through the hearth on which the waste sits. Bottom ash is

removed by dumping into a water bath.

Unburned combustibles and high levels of carbon monoxide and hydrogen exit above

the hearth.

These volatiles are oxidized in the combustion zone where overfire air provides

sufficient excess air and residence time at temperature to ensure complete burnout.

The three Ts of combustion and oxygen provide high combustion efficiency.

Natural gas or oil is supplied to maintain temperatures as high as 2,000F. In some

large municipal waste combustors, called waste-to-energy plants, heat recovery

boilers are used to generate steam for electric generation.

These plants are also referred to as trash-to-steam plants. All incinerator systems

are now regulated by exhaust emissions.

Air pollution control systems are installed to control emissions of particulate matter

including metals and ash, hydrocarbons including dioxins and furans, and acid gases

created from the combustion of wastes containing chlorine, sulfur, phosphorous, and

nitrogen compounds.

Rotary Kiln Incineration.

Solid wastes as well as liquid wastes generated by industry are destroyed by on-site

and commercial-site rotary kiln incinerator systems.

The rotary kiln is a cylindrical refractory -lined shell that is rotated to provide a

tumbling and lifting action to the solid waste materials.

This exposes the waste surface to the flames from fuel burning as well as liquid

waste burning in the rotating kiln.

Flames will also be generated over the surface of waste solids exposed to the heat

and incoming air.

Pumpable sludges and slurries are injected into the kiln through nozzles.

Temperatures for burning vary from 1,300 to 2,400F.

Lower temperatures are often necessary to prevent slagging of certain waste

materials.

The rotary kiln provides excellent mixing through a rotating-tumbling action that

distributes heat evenly to all the waste materials contained within it.

The kiln is the primary combustion chamber (PCC) where organic compounds in the

wastes are volatilized and oxidized as air is introduced into the kiln.

The unburned volatiles enter the secondary combustion chamber (SCC) along with

the hot products of combustion from the PCC where additional oxygen is introduced

and ignitable liquid wastes or fuel can be burned.

Complete combustion of the volatized waste from the PCC, liquid wastes and fuel

occurs in the SCC.

Liquid Injection.

The chemical industries generate liquid wastes that contain toxic organics.

Typical wastes from the agricultural and pharmaceutical plants may contain

compounds such as chlorinated benzenes, vinyl chloride, toluene, phosphorous, and

naphthalene.

On-site liquid injection incinerators are used to destroy these wastes. Liquid injection

incinerators are refractory-lined

Rotary KilnAfterburner chambers, generally cylindrical in shape and equipped with

a primary combustor and often secondary injection nozzles for high-water-content

waste materials.

The liquids are atomized through nozzles, exposed to high temperature fuel burner

flames, vaporized, superheated, and when combined with air in a turbulent zone

attain temperature levels from 1,800 to 3,000F.

Residence time in the chamber is based on the flow volume of these combined

products of combustion (fuel, air, and liquid wastes) in actual cubic feet per second.

The physical volume of the chamber in cubic feet determines the total time of these

gases in the chamber.

This time may vary from 0.5 seconds up to 2.5 seconds.

The toxic organic components of the liquid waste are oxidized to carbon dioxide,

water vapor, oxygen, nitrogen, and acid gases. Acid gases formed are cleaned from

the exhaust stream by wet scrubbers , thus allowing clean products to leave the

exhaust stack.

Incineration has resulted in the ultimate answer to the disposal of these waste

materials.

Emission-Control Systems

A great amount of effort has gone into the proper design of air pollution control

systems associated with incinerators. Most liquid injection incinerators generate acid

gases: hydrogen chloride, sulfur oxides, nitrogen oxides, and others. A proper

scrubber is required for the absorption of acid gases.

In systems burning solid and liquid wastes, the wastes may contain toxic metals

such as arsenic, beryllium, cadmium, chromium, lead, and mercury.

Composting

Aerobic Composting

Aerobic composting is the most commonly used biological process for the conversion

of the organic portion of MSW to a stable humus-like material known as compost.

Applications of aerobic composting include:

o yard waste,

o separated MSW,

o commingled MSW

o Co-composting with waste water sludge.

Important design considerations for aerobic composting process

Item Comment

Particle size For optimum results the size of solid wastes should

be between 25 and 75 mm (1 and 3 inch)

Carbon-to-nitrogen (C/N) ratio

Initial carbon to nitrogen ratios (by mass) between

25 and 50 are optimum for aerobic composting. At

lower ratios, ammonia is given off. Biological activity

is also impeded at lower ratios. At higher ratios,

nitrogen may be a limiting nutrient.

Blending and seeding

Composting time can be reduced by seeding with

partially decomposed solid wastes to the extent of

about 1 to 5 percent by weight. Sewage sludge can

also be added to prepared solid wastes.

Moisture content

Moisture content should be in the range between 50

and 60 percent during the composting process. The

optimum value appears to be about 55 percent.

Mixing/turning

To prevent drying, caking, and air channeling,

material in the process of being composted should

be mixed or turned on a regular schedule or as

required. Frequency of mixing or turning will depend

on the type of composting operation.

Temperature

For best results, temperature should e maintained

between 122 and 131oF (50 and 55oC) for the first

few days and between 131 and 140oF (55 and 60oC)

for the remainder of the active composting period. If

temperature goes beyond 151oF (66oC), biological

activity is reduced significantly.

Control of pathogens

If properly conducted, it is possible to kill all the

pathogens, weeds, and seeds during the composting

process. To do this, the temperature must be

maintained between 140 and 158oF (60 and 70oC)

for 24 h.

Air requirements

Air with at least 50 percent of the initial oxygen

concentration remaining should reach all parts of the

composting material for optimum results, especially

in mechanical systems.

pH control

To achieve an optimum aerobic decomposition, pH

should remain at 7 to 7.5 ranges. To minimize the

loss of nitrogen in the form of ammonia gas, pH

should not rise above about 8.5.

Degree of decomposition

The degree of decomposition can be estimated by

measuring the final drop in temperature, degree of

self heating capacity, amount of decomposable and

resistant organic matter in the composted material,

rise in the redox potential, oxygen uptake, growth of

the fungus Chaetomium gracilis, and the starch-

iodine test.

Low-Solids Anaerobic Digestion

Low-solid anaerobic digestion is a biological process in which organic wastes are

fermented at solid concentrations equal to or less than 4 to 8 percent.

The low-solids anaerobic fermentation process is used in many parts of the world to

generate methane gas from human, animal, and agricultural wastes, and from the

organic fraction of MSW.

Important design consideration for the low-solids anaerobic digestion of the

organic fraction of MSW

Waste component Comment

Size of material

Wastes to be digested should be shredded to a size

that will not interfere with the efficient functioning of

pumping and mixing operations.

Mixing equipment To achieve optimum results and to avoid scum build-

up, mechanical mixing is recommended.

Percentage of solid wastes mixed Although amounts of waste varying from 50 to 90+

with sludge percent have been used, 60 percent appears to be a

reasonable compromise.

Hydraulic and mean cell-residence

time

Washout time is in the range of 3 to 4 d. Use 10 to

20 d for design on results on results of pilot plant

studies.

Solids concentration Equal to or less than 8 to 10% (4 to 8% typical).

Temperature

Between 85 and 100oF (30 to 38oC) for mesophilic

and between 131 and 140oF (55 and 60oC) for

thermophilic reactor.

Destruction of volatile solid wastes

Depends on the nature of the waste characteristic.

Varies from about 60 to 80 percent; 70 percent can

be used for estimating purposes.

Total solids destroyed Varies from 40 to 60 percent, depending on amount

of inert material present originally.

Gas production 8 to 12 ft3/lb (0.5 to 0.75m3/kg) of volatile solids

destroyed (CH4 = 55 percent; CO2 = 45 percent).

High-Solids anaerobic digestion

High-solids anaerobic digestion is a biological process in which the fermentation

occurs at a total solids content of about 22 percent of higher.

High-solids anaerobic digestion processes has lower water requirements and higher

gas production per unit volume of the reactor size.

Important design considerations for the high-solids anaerobic digestion of the

organic fraction of MSW

Item Comment

Size of material

Wastes to be digested should be shredded to a size that will not

interfere with the efficient functioning of feeding and discharging

mechanisms.

Mixing equipment The mixing equipment will depend on the type of reactor to be

used.

Percentage of solid Depends on the characteristics of the sludge.

wastes mixed with

sludge

Solids concentration Between 20 and 35% (22 to 28% typical).

Temperature Between 85 and 100oF (30 and 38oC) for mesophilic and

between 131 and 140oF (55 and 60oC) for thermophilic reactor.

Destruction of

Biodegradable Volatile

Solids (BVS)

Varies from about 90 to 98+ percent depending on the mass

retention time and the BVS loading rate.

Total solids destroyed Varies depending on the lignin content of the feed stocks.

Gas production 10 to 16 ft3/lb of biodegradable volatile solids destroyed (0.625

to 1.0 m3/kg), (CH4 = 50 percent; CO2 = 50 percent).

Factors

Environmental conditions of temperature and pH have an important effect on the

survival and growth of microorganism.

Optimal growth occurs within a fairly narrow range of temperature and pH values,

although the microorganism may be able to survive within much broader limits.

For instance, temperatures below the optimum typically have a more significant

effect on the bacterial growth rate than temperatures above the optimum.

The hydrogen ion concentration, expressed as pH, is not a significant factor in the

growth of microorganisms, in and of itself, within the range from 6 to 9 (which

represents a thousand fold differences in the hydrogen ion concentration.

Moisture content is another essential environmental requirement for the growth of

microorganisms.

The moisture content of the organic wastes to be converted must be known,

especially if a dry process such as composting is to be used.

Two of the most common sources of carbon for cell tissue are organic carbon and

carbon dioxide.

The principal inorganic nutrients needed by microorganism are:

o nitrogen (N),

o sulphur (S),

o phosphorus (P),

o potassium (K),

o magnesium (Mg),

o calcium (Ca),

o iron (Fe),

o sodium (Na),

o chlorine (Cl).

Minor nutrients of importance include

o zinc (Zn),

o manganese (Mn),

o selenium (Se),

o cobalt (Co),

o copper (Cu),

o nickel (Ni)

o tungsten (W).

Pyrolisis

Pyrolysis, as previously defined, is the thermal processing of waste in the complete

absence of oxygen.

Pyrolysis systems use an external heat source to drive the endothermic pyrolysis

reactions in an oxygen-free environment.

Because most organic substances are thermally unstable, they can, upon heating in

an oxygen-free atmosphere, be split through a combination of thermal cracking and

condensation reaction into gaseous, liquid, and solid fractions.

In contrast to the combustion and gasification process, which are highly exothermic,

the pyrolytic process is highly endothermi thus requiring an external heat source.

For this reason, the term destructive distillation is often used as an alternative term

for pyrolysis.

The three major component fractions resulting from the pyrolysis process are the following:

A gas stream, containing primarily hydrogen, methane, carbon monoxide, carbon

dioxide, and various other gases, depending on the organic characteristics of the

material being pyrolyzed.

A liquid fraction, consisting of a tar or an oil stream containing acetic acid, acetone,

methanol, and complex oxygenated hydrocarbons.

A charred fraction, consisting of almost pure carbon plus any inert material originally

present in the solid waste.

3R Concept

1. Reduce

"Reduce", of course, means not buying anything that you don't need. It also means

waste prevention, or "source reduction," and also consuming and throwing away

less. It includes

purchasing durable, long-lasting goods;

seeking products and packaging that are as free of toxins;

redesigning products to use less raw material in production, have a longer

life, or can be used again after its original use.

Source reduction actually prevents the generation of waste in the first place, so it is

the most preferred method of waste management and goes a long way towards

protecting the environment.

Way to reduce :

1. Buy only what you need

Reduce unnecessary waste by avoiding those pointless purchases. Items that

rarely get used can be borrowed or shared with others.

2. Buy products that can be reused

Buy bottles instead of cans and rechargeable batteries. Items such as this

create very little waste, as they dont have to be thrown away after they have

been used just once.

3. Buy all-purpose household cleaner

Instead of buying many different ones for each cleaning role.

4. Buy products with little packaging

So that less packaging ends up in your rubbish bin. For those items you use

regularly, buy them in bulk instead of in smaller amounts. This will save you

money as well as reduce waste.

5. Sell or give away unwanted items

Reduce waste by donating unwanted items to family, friends or neighbours.

You could even sell your possessions in a car-boot sale and earn some extra

cash.

6. Reduce paper waste by cancelling unwanted mail

40% of household wastes came from unwanted mails. Lets reduce paper

waste by subscribing on-line bills.

7. Reducing Hazardous Waste

Many hazardous products cannot be recycled as they contain harmful

chemicals. However, there are ways of reducing waste by dealing with

hazardous products in the correct manner.

8. Buy non-toxic products whenever possible

Many toxic products such as motor oil and pesticides cannot be reused.

9. Recycle motor products

Such as brake fluid, oils and tyres by taking them to your local petrol station.

By recycling these products instead of throwing them away, you are reducing

hazardous waste.

10. When you buy something small, say no thanks to a plastic bag

2. Reuse

Reuse is the second stage of the Waste Hierarchy. Product reuse involves the

multiple use of an item in its original form, for its original purpose or for an

alternative, with or without reconditioning.

In many cases waste that cannot be prevented can be reused instead of

buying new products. For example, you can reuse rechargeable batteries

numerous times to avoid waste from single use batteries. This helps to ensure

that we get the most out of our waste and save valuable natural resources

By reusing goods and purchasing recycled products, less energy is needed to

extract, transport and process raw materials. When energy demand

decreases, fewer fossil fuels are burned and less carbon dioxide is emitted

into the atmosphere. Benefits of reuse are :

1. Saves natural resources. Waste is not just created when consumers

throw items away. Throughout the life cycle of a product from

extraction of raw materials to transportation to processing and

manufacturing facilities to manufacture and use-waste is generated.

Reusing items or making them with less material decreases waste

dramatically. Ultimately, less materials will be recycled or sent to

landfills or waste combustion facilities.

2. Reduces toxicity of waste. Selecting non-hazardous or less

hazardous items is another important component of source reduction.

Using less hazardous alternatives for certain items (e.g., cleaning

products and pesticides), sharing products that contain hazardous

chemicals instead of throwing out leftovers, reading label directions

carefully, and using the smallest amount necessary are ways to reduce

waste toxicity.

3. Reduces costs. The benefits of preventing waste goes beyond

reducing reliance on other forms of waste disposal. Preventing waste

also can mean economic savings for communities, businesses, schools,

and individual consumers.

Communities. More than 6,000 communities have instituted "pay-as-

you-throw" programs where citizens pay for each can or bag of trash

they set out for disposal rather than through the tax base or a flat fee.

When these households reduce waste at the source, they dispose of

less trash and pay lower trash bills.

Businesses. Industry also has an economic incentive to practice

source reduction. When businesses manufacture their products with

less packaging, they are buying fewer raw materials. A decrease in

manufacturing costs can mean a larger profit margin, with savings that

can be passed on to the consumer.

Consumers. Consumers also can share in the economic benefits of

source reduction. Buying products in bulk and with less packaging, or

that are reusable (not single-use) frequently means a cost savings.

What is good for the environment can be good for the pocket as well.

Many items found around the home can be used for different purposes. So

before you throw those items away, think about how they can be reused.

Below are some suggestions of how to reuse those everyday bits and pieces

1. Carrier bags and twist ties. Carrier bags can be reused in the shops or

as bin bags around the house. Paper bags make useful wrapping paper and

twist ties can be used to secure loose items together, such as computer wires

2. Envelopes By sticking labels over the address you can reuse envelopes.

Alternatively, old envelopes can be used as scrap paper to make notes on.

3. Jars and pots. By cleaning glass jars and small pots, you can use them as

small containers to store odds and ends

4. Newspaper, cardboard and bubble wrap Make useful packing material

when moving house or to store items.

5. Old clothes - can be made into other textile items such as cushion covers

or teapot cosy.

6. Scrap paper Can be used to make notes and sketches. Don't forget to

recycle it when you no longer need it.

7. Packaging such as foil and eggs carton can be donated to school and

nurseries, where they can use it in craft and art project

8. Tyres Old tyres can be given to your local petrol station where they will be

recycled. Or you could make a tyre-swing by tying a strong rope around a

tyre and attaching it to a tree

9. Used wood Can be used in woodcarvings for making objects such as a

spice rack or a bird table. Alternatively it could be used as firewood.

3. Recycle

Recycling is a series of activities that includes collecting recyclable materials that

would otherwise be considered waste, sorting and processing recyclables into raw

materials such as fibres, and manufacturing raw materials into new products.

Recycling is when materials are reprocessed and manufactured into the same or

similar products .

Recycling turns materials that would otherwise become waste into valuable

resources. In addition, it generates a host of environmental, financial, and social

benefits.

Materials like glass, metal, plastics, and paper are collected, separated and sent to

facilities that can process them into new materials or products. Recycling is one of

the best environmental success stories of the late 20th century.

Recycling is one of the best ways for you to have a positive impact on the world in

which we live. Recycling is important to both the natural environment and us. We

must act fast as the amount of waste we create is increasing all the time.

The amount of rubbish we create is constantly increasing because:

Increasing wealth means that people are buying more products and ultimately

creating more waste.

Increasing population means that there are more people on the planet to

create waste.

New packaging and technological products are being developed, much of

these products contain materials that are not biodegradable.

New lifestyle changes, such as eating fast food, means that we create

additional waste that isnt biodegradable

Recycling is very important as waste has a huge negative impact on the

natural environment.

1. Harmful chemicals and greenhouse gasses are released from rubbish

in landfill sites. Recycling helps to reduce the pollution caused by

waste.

2. Habitat destruction and global warming are some the effects caused by

deforestation. Recycling reduces the need for raw materials and the

rainforests can be preserved.

3. Huge amounts of energy are used when making products from raw

materials. Recycling requires much less energy and therefore helps to

preserve natural resources.

Recycling is essential to cities around the world and to the people living in

them. No space for waste. Our landfill sites are filling up fast, by 2010, almost

all the landfills in the MALAYSIA will be full.

Reduce financial expenditure in the economy. Making products from raw

materials costs much more than if they were made from recycled products.

Preserve natural resources for future generations. Recycling reduces the need

for raw materials. It uses less energy, therefore preserving natural resources

for the future.

Things can be recycle:

Thing can be recycle How to Recycle Example

1. Metal

a. Aluminum

b. Steel

1. Empty the can

2. Throw the rubbish to

recycle bin provided by local

council

3.Sell the can

4. Use for art and craft project

1. Drink Can

2. Aerosol Container

2. Paper

1. Deposit used paper at your

local recycling bank.

2. Most home recycling bins,

provided by your local council,

usually accept paper products.

3. Only recycle gummed paper

if specified, such as envelopes

and stickers.

4. Reduce paper waste by

cancelling unwanted

deliveries, or read news online

as opposed to buying

newspapers.

5. Put a no junk mail please

sign on your letter box to

reduce unwanted deliveries.

6. Reuse paper around the

home as scrap paper or

packing material. Envelopes

can also be reused.

7. Set your printer to print on

both sides of the paper.

8. Buy recycled paper

whenever possible.

1. Magazine

2. Newspaper

3. Office Paper

4. Cardboard

5. Phone Directories

3. Plastic

1. If your home recycling bin

doesnt take plastic bottles,

then deposit them at your

local recycling bank.

2. Clean bottles before

recycling them.

3. Buy plastic bottles in bulk

whenever possible to reduce

packaging waste.

4. Use for art and craft project

1. HDPE Opaque

bottles

2. PVC Transparent

bottles, with a seam

running across the base

3. PET Transparent

bottles, with a hard

molded spot in the

centre of the base

4. Glass

1. Deposit glass at your

nearest recycling bank by

throwing them into the

appropriate container.

2. Many supermarkets have

glass-recycling banks,

enabling you to recycle glass

on your weekly shop.

3. Most home recycle bins,

provided by your local council,

usually accept glass.

4. Make sure you wash out

the bottle or jar before putting

it into recycling bins.

5. Reuse glass whenever

possible. Jars can be used as

small containers and bottles

can be used as vases.

1. Drinking Bottle

2. Sauce bottle

Others

1. Paint/oil

1. Donate unwanted paints

and varnishes, as others can

reuse them.

2. Look for disposal or

recycling instructions on the

packaging of the product.

3. Civic amenity sites often

take engine oil for recycling.

4. Buy products in bulk

whenever possible to reduce

packaging waste.

5. Use eco-friendly

alternatives whenever possible

1. Paint

2.Paintbrushes

3.Car oil

4.Oil Filter

2. Wood

1. Take wood to civic amenity

sites for recycling.

2. Wood can often be reused

to make other items, such as

a bird table for your garden.

3. Wood can often be added

to your compost heap, such as

sawdust and wood shavings.

4. Buy recycled wood

whenever possible.

Used to produce eco friendly

furniture

1. Old Furniture

3. Batteries

1. Ordinary household

batteries do contain some

hazardous chemicals so ideally

should not be thrown out with

the day to day rubbish.

2. Rechargeable batteries

contain harmful metals, so

should never be thrown away

with daily rubbish, they should

be returned to manufacturer

for disposal or recycled

elsewhere.

3. Local councils or garages

sometimes offer battery-

recycling services.

4. Contact your local council

to see if they are running a

battery collection scheme.

5. Contact the battery

manufacturer for further

recycling advice.

6. Ordinary batteries require a

1. Cell batteries

2.Cell phone batteries

lot of energy to make, so in

order to save energy, use

rechargeable batteries and

electricity mains instead of

ordinary batteries.

7.Rechargable batteries are

the most environmentally

friendly option as can last for

up to several hundred

charging cycles resulting in

less waste being produced.

4. Textiles

1. Donate old clothes to

charity house. Donate only if

the old clothes can still usable

2. Used to make another

textile item such as cushion

cover, blanket or cleaning

clothes

1. Old T-shirt

2. Tare jeans