Bioresource and waste management

WASTE
WASTE
• any material „thrown away”
• regarded as useless and unwanted (at a certain time and place)
INDUSTRIAL PRODUCTION
• change the natural cycle of materials
• use more and more materials
• produce an ever increasing amount of waste

PROBLEMS CAUSED BY IMPROPER
DISPOSAL OF WASTE
Threat to public health
rodents, insects = vectors of diseases (transmit pathogens)
typhoid, plague
poisonous materials
flammable materials
Irreversible environmental damage in ecosystems
terrestrial and aquatic
air pollution (incineration)
water pollution (land burial)
Technical and environmental difficulties + administrative,
economic and social problems

WASTE MANAGEMENT
Solve the technical and environmental difficulties, administrative,
economic and social problems
Tasks to be done:
–Planning
–Design
–Construction
–Operation of facilities for
In the field of:
–Collecting,
–Transporting,
–Processing,
–Disposing of the waste material

residential industrialcommercial
agricultural
mining
construction
Municipal solid waste Hazardous waste

DEFINITION OF SOLID WASTE
 Solid waste is generally defined as non-soluble
material that is discarded in a solid or semi-solid
form. This includes garbage, refuse, sludge and other
discarded domestic materials, as well as waste from
industrial, commercial, agricultural and mining
operations.

Basic terms related to solid
waste
1. Ash : the non-combustible solid by-products of incineration
or other burning process.
2. Bulky waste: large wastes such as appliances, furniture,
and trees and branches, that cannot be handled by normal
MSW processing methods.
3. Co-disposal: the disposal of different types of waste in one
area of a landfill or dump. For instance, sewage sludges
may be disposed of with regular solid wastes.

4. Biodegradable material : any organic material that can be broken
down by microorganisms into simpler, more stable com-pounds.
Most organic wastes (e.g., food, paper) are biodegradable.
5. Compost : the material resulting from com posting. Compost, also
called humus, is a soil conditioner and in some instances is used as
a fertilizer.
6. Composting : biological decomposition of solid organic materials by
bacteria, fungi, and other organisms into a soil-like product.
7. Disposal : the final handling of solid waste, following collection,
processing, or incineration. Disposal most often means placement of
wastes in a dump or a landfill.

8. Environmental risk assessment (EnRA) : an evaluation of the
interactions of agents, humans, and ecological resources.
Comprised of human health risk assessment and ecological risk
assessment, typically evaluating the probabilities and magnitudes of
harm that could come from environmental contaminants.
9. Environmental impact assessment (EIA) : an evaluation designed
to identify and predict the impact of an action or a project on the
environment and human health and well-being. Can include risk
assessment as a component, along with economic and land use
assessment.

Sources and Types of Solid
Wastes
 Sources of solid wastes in a community are:
• Residential
• Commercial
• Institutional
• Construction and Demolition
• Municipal Services
• Treatment Plant Sites
• Industrial
• Agricultural

Sources and Types of Solid Wastes
Types of solid wastesTypical facilities, activities,
locations where wastes are
generated
Source
Food wastes, paper, cardboard, plastics,
textiles, leather, yard wastes, wood,
glass, metals, ashes, special wastes (e.g.,
bulky items, consumer electronics, white
goods, batteries, oil, tires), and
household hazardous wastes
Single and multifamily
dwellings
Residential
Industrial process waste, scrap materials,
etc. Non - industrial waste including food
wastes, construction and demolition
wastes, rubbish, ashes , hazardous
wastes, ashes, special wastes
Light and heavy
manufacturing, fabrication,
construction sites, power and
chemical plants
Industrial
Table 1: Sources and Types of Solid Wastes within a Community

Types of solid wastesTypical facilities, activities,
generated
Source
Paper, cardboard, plastics, wood, food
wastes, glass, metals, special wastes,
hazardous wastes
Stores, hotels, restaurants,
markets, office buildings,
etc.
Commercial
Same as commercialSchools, hospitals, prisons,
government centers
Institutional
Wood, steel, concrete, dirt, etc.New construction sites,
road repair, renovation
sites, demolition of
buildings, broken pavement
Construction and Demolition
Table 1: Sources and Types of Solid Wastes within a Community (Cont’d)

Table 1: Sources and Types of Solid Wastes within a Community (Cont’d)Types of solid wastesTypical facilities, activities,
generated
Source
Street sweepings; landscape and tree
trimmings; general wastes from parks,
beaches, and other recreational areas;
sludge
Street cleaning, landscaping,
parks, beaches, other
recreational areas, water and
wastewater treatment plants
Municipal
Services (excluding
treatment facilities)
Spoiled food wastes, agricultural wastes,
rubbish, hazardous waste.
Field and row crops, orchards,
vineyards, dairies, feedlots,
farms, etc.
Agricultural

Nature of Municipal Solid Waste
 Organic (Combustible)
 Inorganic (non-combustible)
 Putrescible
 Recyclable
 Hazardous
 Infectious

Functional Elements:
The activities involved with the management of solid
wastes from the point of generation to final disposal
have been grouped into six functional elements.
(i) Waste generation
(ii) On site handling, storage and processing
(iii) Collection
(iv) Transfer and transport
(v) Processing and recovery
(vi) Disposal

Functional element Description
Waste generation Those activities in which materials are
identified as no longer being of value
and are either thrown away or gathered
together for disposal
On site handling, storage and
processing
Those activities associated with the
handling, storage and processing of
solid wastes at or near the point of
generation.
Collection Those activities associated with
gathering of solid wastes and the
hauling of wastes after collection to the
location where collection vehicle is
emptied.
Transfer and transport Those activities associated with (i)
Transfer of wastes from the smaller
collection vehicle to larger transport
equipment and (ii) The subsequent
transport of the wastes, usually over
long distance, to the disposal site.

Processing and recovery Those techniques, equipment and
facilities used both to improve the
efficiency of other functional elements
and to recover usable materials,
conversion products.
Disposal Those activities associated with ultimate
disposal of solid wastes, including
wastes collected and transported
directly to a landfill site, semisolid waste
from treatment plants.

Solid waste generation
Solid wastes include all solid or semisolid
material that is no longer considered of
sufficient value to retain in a given setting.

Factors that affect generation rates
• Season of the year
• Frequency of collection
• Characteristics of the population
• Public attitude
• Geographical location

Disposal of solid waste
• Mechanical volume reduction or Compaction -
Mechanical compactors are used to compress the
waste materials so as to form bales that can be
placed in big containers.
• Incineration or thermal volume reduction -
Combustible waste such as plastics, cardboard and
rubber are subjected to burning at high temperature
in hearth furnaces. If not carried out properly
incineration results in air pollution.

• Open dumping - It is done in low lying areas and
outskirts of city. This method has various disadvantages
as it causes foul smell due to release of obnoxious
gases. Moreover it becomes breeding ground for flies,
mosquitoes which causes various health hazards.
• Destructive distillation or pyrolysis – Heating the solid
waste under anaerobic conditions is referred to as
pyrolysis. The organic waste spilt up in fractions of CO,
CO2, CH4 and tar.

• Land filling- Solid waste is dumped into low
lying areas in the upper layers of the earth’s
surface and spread in thin layers. With course of
time decomposition of the organic matter occurs
and there is conversion to stabilized end
products. It is a simple and economical method.
• Land farming – In this method the organic
waste is either applied on top of the land or
injected below the soil surface where it
undergoes bacterial decomposition.

1.On-site Handling, On-site Storage
2.Collection services: types and methods
3.Vehicle and labor requirements
4.Types of Collection systems (hauled container
system, stationary container system)
Solid Waste Collection and Transport

ON-SITE HANDLING:
 Activities associated with the handling of SW until
they are placed in the containers used for storage
before collection
ON-SITE STORAGE:
Factors considered:
1. Container Locations
2. Public health
3. Aesthetics
4. Types of containers used
5. Methods of Collection

Factors considered
1.)Types of Containers:
- Depend on:
 Characteristics of SW collected
E.g. Large storage containers (Domestic SW:
flats/apartment)
 Containers
 Large containers on a roller
(Commercial/Industrial)
• Collection frequency
• Space available for the placement of containers

Residential; refuse bags (7 -10 litres)
- Rubbish bins - 20 -30 litres
- Large mechanical containers - more commonly used
to cut costs (reduce labor, time , & collection costs)
- must be standardized to suit collection equipment.
2.)Container Locations:
-side/rear of house
- special enclosures (apartment)
- Basement (apts. in foreign countries)/ newer
complexes

3.) Public Health:
- relates to on-time collection to avoid the spread of
diseases by vectors, etc.
4.) Aesthetics:
-must be pleasing to the eye (containers must be
clean, shielded from public’s view).

5.)Collection of SW:
Malaysia (other developing nations) - labor
and capital intensive.
- Major problems:
–Poor building layouts
–Road congestion - time cost, transport
costs.
–Physical infrastructure
–Old containers used (leaky/ damaged)
–Absence of systematic methods (especially
at apartments, markets)

 Collections were made by:
1. Municipal/ District Council
2. Private firm under contract to municipal
3. Private firm contract with private residents

TYPES OF COLLECTION:
• Municipal Collection Services:
a) Residential:
i) Backyard collection (100-120 liters)
– Quickest/ economical
– Crew: 1 driver + 1 or 2 collectors
ii) House-to-house collection where refuse
bags used in 20-30 liter bins.

iii) High-rise apartment or flats, specially designed
communal storage or roll-on-roll-offs (RORO’s).
iv) Future trend: mechanically-equipped trucks.
b) Commercial-Industrial Collection Services
( > 12 m3 )
i. Large movable and stationary containers
ii. Large stationary compactors (to form bales)

Collection Frequency
Residential areas : everyday/ once in 2 days
- communal/ commercial : daily
- food waste - max. period should not exceed :
• the normal time for the accumulation of waste to fill
a container
• the time for fresh garbage to emit fouls odor
• the length of fly-breeding cycle ( < 7 days).

TYPES OF COLLECTION SYSTEMS
on the basis of their mode of operation
1. Hauled Container System (HCS)
2. Stationary Container System (SCS)

1) HCS:
- Container is hauled to disposal sites, emptied,
and returned to original location or some other
location
- Suitable for areas where higher waste
generation
- Types:
» Hoist truck : 2 - 10 m3
» Tilt frame container: 10 - 40 m3 -
» Trash trailer - for heavy, bulky rubbish
(construction, commercial, usually open top
container);
» 2 crew per vehicle.

• The container is sited at a location. In accordance with
some cycle, the container is picked up and hauled off to
the disposal area where the container is emptied and
returned to the original location.
• The truck had no container; the container is carried by
the truck.
Advantages:
• - Useful when the generation rate is high and the
containers are large.
• - May eliminate spillage associated with multiple smaller
containers.
• - Flexible. Need more capacity, use a larger container.

Disadvantage:
- If the containers are not filled, low utilization
rate.
- Types:
• Hoist truck – In the past, hoist trucks were
widely used at military installations, with the
advent of self-loading collection vehicles, this
system is applicable only in limited number of
cases.

• Tilt-frame - Assembly on truck allows sliding of
large containers on and off the truck.
• Trash-trailer-The slider assembly is not part of the
truck, but part of the trailer.

2.SCS:
 The container used to store waste remain at the point
of generation; except when moved to other location
to be emptied.
Types include:
Mechanically-loaded system
- System with self loading compactors.
Manually-loaded collection vehicle(more common).
- This loading method is used in the collection of
residential wastes & litter.
Used for residential/commercial sites.
Vehicle with internal compaction mechanism or un-
compacted (open top lorry - side loaded).

 The major advantage is that the vehicle does
not travel to the disposal area until it is full
yielding higher utilization rates.
The major disadvantages include:
• The system is not flexible in terms of picking
up bulky goods.
• Wastes e.g. demolition, that may damage the
relatively delicate mechanisms.
• Large volume generations may not have room
for storing large containers

SWM - strategies to improve
• Increasing number of vehicles and staff
• Rearranging work areas to increase productivity
• Opening up new tenders for newer
development areas
• Repairing vehicles
• Upgrading drainage-cleaning performance

Equipment (avg. life 5-7 years)
• Residential collection vehicle (SCS) - packer
truck; most compact waste
• Rear loaders - larger hopper less necessary with
elimination of larger, bulky items
• Side loaders - 2 person crew (driver and loader)
• Mechanically loaded
• Front Loader, residential waste place in bin then
cycled (loaded and compacted)

Mechanically loaded side loader
Front Loader
Rear Loader

• Commercial (SCS) - self loaders (rear, side, front)
• Commercial (HCS)
 Hoist truck; small operations, few pickup locations, bulky items
 Tilt frame - large containers, wide use
 Trash trailers - heavy rubbish
Hoist Truck Trash Trailer

Collection Vehicles
Side loader
Grapple trucks

There are Two Types of HCS Systems
• Conventional - the system described in the text. A
round trip starting from the time the truck arrives at a
waste generation site would be:
1.Pickup the container, pc
2.Drive to the disposal site with the used container, h
3.Empty the container at the disposal site, s
4.Drive to the generation site with the empty container, h
5.Return the empty container to the pickup location in step
1, uc
6.Drive to the next pickup location with an empty truck (no
container), dbc
• Note that in order to include all of the collection
activities in the round trip, the starting and stopping
points are different.

Swap container
• The service vehicle arrives at a service location with an
empty container. It replaces the used container with the
empty one and then hauls the used one to the disposal
site. A round trip starting from the time the truck leaves
the disposal site would be:
– drive to the pickup location with an empty container on the
truck, h
– unload the empty container, pickup the used container,
reposition the empty container, (uc+pc+zc)
– drive to the disposal site, h
– empty the container at the disposal site, s
The round trip sequence is now complete. After the at-site
time, the vehicle will start the round trip sequence again
and drive to the next site.

A. Definition of Terms
1.) Pickup (Phcs or scs)
Phcs: The time spent:
- driving to the next container after an empty
container has been deposited.
- the time spent pickup the loaded container.
- the time required to redeposit the container after it
has been emptied.
Pscs: Refers to the time spent loading the vehicle,
beginning with the stop to load the first container
and ending when the last container has been
loaded.

2.) Haul (h)
Does not include actually picking up the loaded
container or redepositing the empty container nor
the time spent at the location where the waste is
unloaded.
HCS- The time required to reach the location where
the waste will be emptied, starting when the
container has been loaded on the truck and
continuing through unloading until the truck
arrives at the location where the empty container
is to be redeposited.
SCS - The time required to reach the location where
the full vehicle will be emptied and continuing
until the truck arrives at the location where the
first container will be emptied for the next route.

3.) At-Site (s)
The time spent at the site (landfill,transfer
station) where the system is unloaded
including waiting time.
4.) Off-Route (W)
• Non-productive activities
- Necessary - Check in, check out, meeting,
breaks.
- Unnecessary - Personal errands, extended
coffee breaks
• Typically 15%

B. Hauled Container System
Equations :
Thcs = (Phcs + s + h)
 The time required for a trip is the sum of the
pickup time, the time on site and the haul time.
 The haul time is essentially a function of the
distance traveled.
The pickup time may be expressed as follows:
Phcs = pc + uc + dbc

In plain English, the pickup time is the sum
required to pickup the container, to unload the
container and drive between containers
(p+u+d).

4. Collection Routes
A. General
Use a heuristic (common sense), trial and error approach consistent with
the philosophy of collecting the most waste with least resources in the
context of constraints such as equipment breakdowns, holidays and
vacations, good labor practices and the following guidelines:
- Crew size and vehicles must be known and coordinated.
- Routes should begin and end near arteries
- Topographic and physical boundaries should be route boundaries.
- Start at the top of a hill and work downward.
- Last collection point should be near disposal site.
- Traffic problems should be dealt with early in the morning.
- Extremely large load should be dealt with early in the morning

B. Layout of Collection Routes
• Location maps showing data concerning the sources including
location, collection frequency, number of containers.
• Data analysis, try to balance the routes in accordance with
pickups and time.
• Preliminary layout of routes, start at the depot and do a route.
An idea of truck capacity vs. loads is in order.
• Fine tune the preliminary design.

• Functional element of transfer and transport refers to the means, facilities
used to effect the transfer of wastes from one location to another, usually
more distant, location.
• Contents of relatively small collection vehicles are transferred to larger
vehicles that are used to transport the waste over extended distances either
to Materials Recovery Facilities( MRFs) or to disposal sites.
Transfer and Transport

Generation
Collection
Transport
Final disposal
Transfer

• Transfer and transport operations are also used
in conjunction with MRFs to transport
recovered materials to markets or waste-to-
energy facilities and to transport materials to
landfills.
• Today, with rising labor, operating, and fuel
costs and the absence of nearby solid waste
disposal sites, transfer stations are becoming
common.

Need for transfer operations
Factors that make the use of transfer operations attractive:
• Occurrence of illegal dumping due to excessive
haul distances
• Location of disposal sites relatively far from
collection routes
• Use of small-capacity collection vehicles
• Existence of low-density residential service areas
• Use of a hauled container system with relatively
small containers for collection of wastes from
commercial sources
• Use of hydraulic or pneumatic collection systems

Types of Transfer Stations
Transfer stations are used to accomplish the transfer of
solid wastes from collection and other small vehicles to
larger transport equipment.
Depending on the method used to load the transport
vehicles, transfer stations may be classified into three
general types;
Direct-load
Storage-load
Combined direct-load and discharge-load

Storage-load
Direct-load
Combined direct-load & discharge-load

Direct-load transfer station with compactors
Figure - Direct-load transfer station equipped with stationary
compactor

Direct-load transfer station with compactors

Storage-load transfer station
Figure - Storage-load transfer station with processing and
compaction facilities

Means of Transport
 Motor vehicles, railroads and ocean-going vessels are the
principle means used to transport solid wastes.
 Vehicles used for transport should satisfy the following
requirements;
 Wastes must be transported at minimum cost
 Wastes must be covered during hauling operation
 Vehicles must be designed for highway traffic
 Vehicles capacity must be such that the allowable weight limits are
not exceeded
 Methods used for unloading must be simple and dependable

Transfer Stations - Istanbul
Collection vehicles (Unloading)
Compactor

Transport to landfill - Istanbul
Transport vehicle in transfer station
Transport vehicle in landfill

Is a transfer facility appropriate for your
community?
Compare the costs and savings associated with the
construction and operation of a transfer facility.
 Benefits:
Lower collection costs
Reduced fuel and maintenance costs for collection
vehicles
 Increased flexibility in selecting disposal facilities
 The option to separate and recover recyclables or
compostables at the transfer site
 The opportunity to shred or bale wastes before disposal

Possible drawbacks:
 Difficulty with sitting and permitting, particularly
in urban areas.
 Construction and operation costs may make them
undesirable for some communities.

Transfer Station Design
Important factors in the design of transfer stations;
 Type of transfer operation
 An adequate area is necessary in case of waste recovery
 Storage and throughput capacity requirements
 Collection vehicles do not have to wait too long to unload
 Equipment and accessory requirements
 Sanitation requirements

Location of Transfer Stations
Transfer stations should be located;
 As near as possible to the solid waste production areas to be served.
 Within easy access of major arterial highway routes as well as near
secondary or supplemental means of transportation .
 Where there will be a minimum of public and environmental objection to
the transfer operations.
 Where construction and operation will be most economical.
 Additionally, if the transfer station site is to be used for processing
operations involving materials recovery and/or energy production, the
requirements for those operations must also be assessed.

Processing Techniques & Equipments
• PURPOSE OF PROCESSING
 The processing of wastes helps in achieving the best possible benefit
from every functional element of the solid waste management (SWM)
system and, therefore, requires proper selection of techniques and
equipment for every element.
 Accordingly, the wastes that are considered suitable for further use
need to be paid special attention in terms of processing, in order that
we could derive maximum economical value from them.

The purposes of processing, essentially, are:-
(i) Improving efficiency of SWM system: Various processing techniques
are available to improve the efficiency of SWM system. For example,
before waste papers are reused, they are usually baled to reduce
transporting and storage volume requirements.
 In some cases, wastes are baled to reduce the haul costs at disposal site,
where solid wastes are compacted to use the available land effectively.
 If solid wastes are to be transported hydraulically and pneumatically,
some form of shredding is also required. Shredding is also used to
improve the efficiency of the disposal site.

(ii) Recovering material for reuse:
 Usually, materials having a market, when present in wastes in sufficient
quantity to justify their separation, are most amenable to recovery and
recycling.
 Materials that can be recovered from solid wastes include paper, cardboard,
plastic, glass, ferrous metal, aluminium and other residual metals.
(iii) Recovering conversion products and energy:
 Combustible organic materials can be converted to intermediate products
and ultimately to usable energy.
 This can be done either through incineration, pyrolysis, composting or bio-
digestion.

MECHANICAL VOLUME AND SIZE REDUCTION
 Mechanical volume and size reduction is an important factor in
the development and operation of any SWM system.
 The main purpose is to reduce the volume (amount) and size of
waste, as compared to its original form, and produce waste of
uniform size.

 Volume reduction or compaction
• Volume reduction or compaction refers to densifying wastes in order to
reduce their volume. Some of the benefits of compaction include:
 Reduction in the quantity of materials to be handled at the disposal
site;
 Improved efficiency of collection and disposal of wastes;
 Increased life of landfills;
 Economically viable waste management system.

• Disadvantages associated with compaction:
 Poor quality of recyclable materials sorted out of compaction vehicle;
 Difficulty in segregation or sorting (since the various recyclable materials
are mixed and compressed in lumps);
 Bio-degradable materials (e.g., Leftover food, fruits and vegetables)
destroy the value of paper and plastic material.

Equipment used for compaction
• Based on their mobility, we can categories the compaction
equipment used in volume reduction under either of the
following:
(i) Stationary equipment:
 This represents the equipment in which wastes are brought to, and loaded
into, either manually or mechanically.
 In fact, the compaction mechanism used to compress waste in a collection
vehicle, is a stationary compactor.
 According to their application, stationary compactors can be described
as light duty(e.g., those used for residential areas), commercial or light
industrial, heavy industrial and transfer station compactors.

• Usually, large stationary compactors are necessary, when
wastes are to be compressed into:
 Steel containers that can be subsequently moved manually or mechanically;
 Chambers where the compressed blocks are banded or tied by some means
before being removed;
 Chambers where they are compressed into a block and then released and
hauled away untied;
 Transport vehicles directly.

(ii) Movable equipment:
 This represents the wheeled and tracked equipment used to place and
compact solid wastes, as in a sanitary landfill.
Let us now move on to the discussion of
compactors used in the transfer station.

Compactors
• According to their compaction pressure, we can divide the
compactors used at transfer stations as follows:
(i) Low-pressure (less than 7kg/cm2) compaction:
 This includes those used at apartments and commercial establishments,
bailing equipment used for waste papers and cardboards and stationary
compactors used at transfer stations.
 In low-pressure compaction, wastes are compacted in large containers.
 Note that portable stationary compactors are being used increasingly by a
number of industries in conjunction with material recovery options,
especially for waste paper and cardboard.

(ii) High-pressure (more than 7kg/cm2) compaction:
 Compact systems with a capacity up to 351.5 kg/cm2 or 5000 lb/in2 come
under this category.
 In such systems, specialized compaction equipment are used to compress
solid wastes into blocks or bales of various sizes.
 The volume reduction achieved with these high-pressure compaction
systems varies with the characteristics of the waste.

When wastes are compressed, their volume is reduced, which is
normally expressed in percentage and computed by equation:-
Volume Reduction (%) = Vi – Vf / Vi *100
The compaction ratio of the waste is given in equation
Compaction ratio = Vi / Vf
where Vi = volume of waste before compaction, m3 and Vf =
volume of waste after compaction, m3

 The relationship between the compaction ratio and percent
of volume reduction is important in making a trade-off
analysis between compaction ratio and cost.
 Other factors that must be considered are final density of waste
after compaction and moisture content.
 The moisture content that varies with location is another
variable that has a major effect on the degree of compaction
achieved.
 In some stationary compactors, provision is made to add
moisture, usually in the form of water, during the compaction
process.

Selection of compaction equipment
• To ensure effective processing, we need to consider the
following factors, while selecting compaction equipment:
 Characteristics such as size, composition, moisture content,
and bulk density of the waste to be compacted.
 Potential uses of compacted waste materials.
 Design characteristics such as the size of loading chamber,
compaction pressure, compaction ratio, etc.
 Operational characteristics such as energy requirements,
routine and specialized maintenance requirement, simplicity of
operation, reliability, noise output, and air and water pollution
control requirement.

 Site consideration, including space and height, access, noise
and related environmental limitations.
Size reduction or shredding
 This is required to convert large sized wastes (as they are
collected) into smaller pieces.
 Size reduction helps in obtaining the final product in a
reasonably uniform and considerably reduced size in
comparison to the original form.

 In the overall process of waste treatment and disposal, size
reduction is implemented ahead of:-
• Recovering materials from the waste stream for recycling.
• Making the waste a better fuel for incineration waste
energy recovery facilities.

• The size reduction techniques, coupled with separation
techniques such as screening, result in a more homogeneous
mixture of relatively uniform size, moisture content and
heating value, and thereby improving the steps of incineration
and energy recovery.
• Reducing moisture, i.e., drying and dewatering of wastes

Type Mode of action Application
Small grinders Grinding, mashing Organic residential solid wastes
Chippers Cutting, slicing Paper, cardboard, tree trimmings, yard waste,
wood, plastics
Large grinders Grinding, mashing Brittle and friable materials, used mostly in
industrial operation
Jaw crushers Crushing, breaking Large solids
Shredders Shearing, tearing All types of municipal wastes
Cutters, Clippers Shearing, tearing All types of municipal wastes
Hammer mills Breaking, tearing,
cutting, crushing
All types of municipal wastes

Figure - Hammer Mill: An Illustration

Selection of size reduction equipment
 The factors that decide the selection of size reduction
equipment include the following:
• The properties of materials before and after shredding.
• Size requirements for shredded material by component.
• Method of feeding shredders, provision of adequate shredder
hood capacity (to avoid bridging) and clearance requirement
between feed and transfer conveyors and shredders.
• Types of operation (continuous or intermittent).

• Operational characteristics including energy requirements,
routine and specialized maintenance requirement, simplicity of
operation, reliability, noise output, and air and water pollution
control requirements.
• Site considerations, including space and height, access, noise
and environmental limitations.

Chemical volume reduction
• Chemical volume reduction is a method, wherein volume
reduction occurs through chemical changes brought within
the waste either through an addition of chemicals or changes
in temperature.
• Incineration is the most common method used to reduce the
volume of waste chemically, and is used both for volume
reduction and power production.
• These other chemical methods used to reduce volume of waste
chemically include pyrolysis, hydrolysis and chemical
conversions.

 Note that prior to size or volume reduction, which we
discussed, the component separation is necessary to avoid the
problem of segregating or sorting recyclable materials from
the mixed and compressed lumps of wastes and the poor
quality of recyclable materials sorted out of compaction
vehicles.
COMPONENT SEPARATION
 Component separation is a necessary operation in
which the waste components are identified and sorted
either manually or mechanically to aid further
processing. This is required for the:

• Recovery of valuable materials for recycling;
• Preparation of solid wastes by removing certain components
prior to incineration, energy recovery, composting and biogas
production.
 The most effective way of separation is manual sorting in
households prior to collection. In many cities (e.g., Bangalore,
Chennai, etc., in India), such systems are now routinely used.
 The municipality generally provides separate, easily
identifiable containers into which the householder deposits
segregated recyclable materials such as paper, glass, metals,
etc …

• This technique has been in use for a number of years in
industrial operations for segregating various components from
dry mixture.
• Air separation is primarily used to separate lighter materials
(usually organic) from heavier (usually inorganic) ones.
• The lighter material may include plastics, paper and paper
products and other organic materials. Generally, there is also a
need to separate the light fraction of organic material from the
conveying air streams, which is usually done in a cyclone
separator.

 The light fraction may be used, with or without further size
reduction, as fuel for incinerators or as compost material.
 There are various types of air classifiers commonly used, some
of which are listed below:
(i) Conventional type: This, is one of the simplest types of air
classifiers:
In this type, when the processed solid wastes are dropped
into the vertical chamber, the lighter material is carried by the
airflow to the top while the heavier materials fall to the
bottom of the chamber.

 The control of the percentage split between the light and heavy
fraction is accomplished by varying the waste loading rate,
airflow rate and the cross section of chambers.
(ii) Zigzag air classifier: An experimental zigzag air classifier,
shown in Figure below, consists of a continuous vertical
column with internal zigzag deflectors through which air is
drawn at a high rate:

Zigzag Air Classifier
 Shredded wastes are introduced at the top of the column at a
controlled rate, and air is introduced at the bottom of the
column.
 As the wastes drop into the air stream, the lighter fraction is
fluidized and moves upward and out of column, while the
heavy fraction falls to the bottom.
 Best separation can be achieved through proper design of the
separation chamber, airflow rate and influent feed rate.

(iii) Open inlet vibrator type:

(iii) Open inlet vibrator type:
 In this type of air classifier, the separation is accomplished by
a combination of the following actions:
 Vibration: This helps to stratify the material fed to the
separator into heavy and light components.
 Due to this agitation, the heavier particles tend to settle at the
bottom as the shredded waste is conveyed down the length of
the separator.
 Inertial force:
 In this action, the air pulled in through the feed inlet imparts an
initial acceleration to the lighter particle, while the wastes
travel down the separator as they are being agitated.

• Air pressure:
 This action refers to the injection of fluidizing air in two or
more high velocity.
 It has been reported that the resulting separation is less
sensitive to particle size than a conventional vertical air
classifier, be it of straight or zigzag design
 An advantage of this classifier is that an air lock feed
mechanism is not required and wastes are fed by gravity
directly into the separator inlet.

The factors that are to be considered for selecting air separation
equipment include the following: -
 Characteristics of the material produced by shredding
equipment including particle size, shape, moisture content and
fiber content.
 Material specification for light fraction.
 Methods of transferring wastes from the shredders to the air
separation units and feeding wastes into the air separator.

Selection of air separation equipment
 Characteristics of separator design including solids-to-air ratio,
fluidizing velocities, unit capacity, total airflow and pressure
drop.
 Operational characteristics including energy requirement,
maintenance requirement, simplicity of operation, proved
performance and reliability, noise output, and air and water
pollution control requirements.
 Site considerations including space and height access, noise

• The most common method of recovering ferrous scrap from
shredded solid wastes involves the use of magnetic recovery
systems.
• Ferrous materials are usually recovered either after shredding
or before air classification .
• When wastes are mass-fired in incinerators, the magnetic
separator is used to remove the ferrous material from the
incinerator residue.
• Magnetic recovery systems have also been used at landfill
disposal sites.

• Various types of equipment are in use for the magnetic separation of
ferrous materials. The most common types are the following:
 In this type of separator, a permanent magnet is used to attract the
ferrous metal from the waste stream.
 When the attracted metal reaches the area, where there is no
magnetism, it falls away freely. This ferrous metal is then collected
in a container.
 This type of separation device is suitable for processing raw
refuse, where separators can remove large pieces of ferrous metal
easily from the waste stream.

 This consists of a drum type device containing permanent
magnets or electromagnets over which a conveyor or a similar
transfer mechanism carries the waste stream.
 The conveyor belt conforms to the rounded shape of the
magnetic drum and the magnetic force pulls the ferrous
material away from the falling stream of solid waste.

Figure - Pulley Type Permanent Magnetic Separator

Selection of magnetic separation equipment
We must consider the following factors in the selection of magnetic
separation equipment:
 Characteristics of waste from which ferrous materials are to be separated
(i.e., the amount of ferrous material, the tendency of the wastes to stick to
each other, size, moisture content, etc.)
 Characteristics of the separator system engineering design, including
loading rate, magnet strength, conveyor speed, material of construction, etc.
 Operational characteristics, including energy requirements, routine and
specialized maintenance requirements, simplicity of operation, reliability,
noise output, and air and water pollution control requirements.

 Locations where ferrous materials are to be recovered from
solid wastes.
 Site consideration, including space and height, access, noise

Screening
• Screening is the most common form of separating solid
wastes, depending on their size by the use of one or more
screening surfaces .
• Screening has a number of applications in solid waste resource
and energy recovery systems .
• Screens can be used before or after shredding and after air
separation of wastes in various applications dealing with both
light and heavy fraction materials.
• The most commonly used screens are rotary drum screens and
various forms of vibrating screens .

 Note that rotating wire screens with relatively large openings
are used for separation of cardboard and paper products,
 while vibrating screens and rotating drum screens are
typically used for the removal of glass and related materials
from the shredded solid wastes.

Selection of screening equipment
• The various factors that affect the selection of screens include
the following:
 Material specification for screened component.
 Location where screening is to be applied and characteristics
of waste material to be screened, including particle size, shape,
bulk, density and moisture content.
 Operational characteristics, including energy requirements,
maintenance requirements, simplicity of operation, reliability,
noise output and air and water pollution control requirements.

 Site considerations such as space and height access, noise and
related environmental limitations.
 The efficiency of screen can be evaluated in terms of the
percentage recovery of the material in the feed stream by
using Equation :-
where U = weight of material passing through screen (underflow) kg/h;
F = weight of material fed to the screen, kg/h;
Wu = weight fraction of material of desired size in underflow;
Wf = weight fraction of material of desired size in feed.

 Wf = Weight of sample / Weight of material fed to the screen
 Wu = Weight of sample in underflow / Total weight of material in
underflow
 The effectiveness of the screening operation can be determined by:
Effectiveness = recovery *rejection
where, rejection = 1 – recovery of undesired material
= 1 – U( 1- Wu) / F( 1- Wf )
Therefore, the effectiveness of screen is:
Effectiveness = U* Wu/ F* Wf *[1- U(1- Wu)/ F( 1- Wf )]

Other separation techniques
• Besides the mechanical techniques we studied earlier for
segregating wastes, there are others. A description of some of
these other separation techniques is given below:
(i) Hand-sorting or previewing: Previewing of the waste
stream and manual removal of large sized materials is
necessary, prior to most types of separation or size reduction
techniques.
 This is done to prevent damage or stoppage of equipment
such as shredders or screens, due to items such as rugs,
pillows, mattresses, large metallic or plastic objects, wood
or other construction materials, paint cans, etc.

(ii) Inertial separation: Inertial methods rely on ballistic or
gravity separation principles to separate shredded solid wastes
into light (i.e., organic) and heavy (i.e., inorganic) particles.

Figure - Ballistic Inertial Separator

Figure - Inclined Conveyor Separator

(iii) Flotation: In the flotation process, glass-rich feedstock, which is
produced by screening the heavy fraction of the air-classified wastes after
ferrous metal separation, is immersed in water in a soluble tank .
 Glass chips, rocks, bricks, bones and dense plastic materials that sink to the
bottom are removed with belt scrappers for further processing.
 Light organic and other materials that float are skimmed from the surface.
 These materials are taken to landfill sites or to incinerators for energy
recovery .
 Chemical adhesives (flocculants) are also used to improve the capture of
light organic and fine inorganic materials.

(iv) Optical sorting:
 Optical sorting is used mostly to separate glass from the waste stream,
 And this can be accomplished by identification of the transparent properties
of glass to sort it from opaque materials (e.g., Stones, ceramics, bottle caps,
corks, etc.) in the waste stream.
 An optical sorting machinery is, however, complex and expensive.

Figure 5.11 Simplified Scheme of Electronic Sorter

So far, we discussed component separation
through air classifiers, magnetic separators,
screens, and hand sorting, flotation, optical sorting
and inertial separators.
 Now, in case, however, the waste consists of moisture, we need to
remove it for efficient management. It is in this regard that drying and
dewatering are considered the most appropriate means of removal of
moisture. We will study this next….

DRYING AND DEWATERING
• Drying and dewatering operations are used primarily for incineration
systems, with or without energy recovery systems.
• These are also used for drying of sludges in wastewater treatment plants,
prior to their incineration or transport to land disposal.
• The purpose of drying and dewatering operation is to remove moisture
from wastes and thereby make it a better fuel .
• Sometimes, the light fraction is pelletised after drying to make the fuel
easier to transport and store, prior to use in an incinerator or energy
recovery facility.

DRYING
• The following three methods are used to apply the heat required for
drying the wastes:
(i) Convection drying:
 In this method, hot air is in direct contact with the wet solid waste
stream.
(ii) Conduction drying:
 In this method, the wet solid waste stream is in contact with a
heated surface.
(iii) Radiation drying:
 In this method, heat is transmitted directly to the wet solid waste
stream by radiation from the heated body.
 Of these three methods, convection drying is used most
commonly.

Figure - illustrates a rotary drum dryer used in the cement
industry:

• As above figure illustrates, a rotary drum dryer is composed of a
rotating cylinder, slightly inclined from the horizontal through which the
material to be dried and the drying gas are passed simultaneously.
• The drying of material in a direct rotary dryer occurs in the following
stages: -
 Heating the wet material and its moisture content to the constant-rate
drying temperature.
 Drying the material substantially at this temperature.
 Heating of material to its discharge temperature and evaporation of
moisture remaining at the end of the stage.

• The retention time in the rotary drum is about 30 – 45
minutes. The required energy input will depend on the
moisture content, and the required energy input can be
estimated by using a value of about 715 KJ/kg (or 1850
Btu/1b) of water evaporated.

Factors, we need to consider in the selection of a drying
equipment that include the following:
 Properties of material to be dried.
 Drying characteristics of the materials, including moisture content,
maximum material temperature and anticipated drying time.
 Nature of operation, whether continuous or intermittent.
 Specification of final product, including moisture content.
 Operational characteristics, including energy requirements,
maintenance requirements, simplicity of operation, reliability, noise
output and air and water pollution control requirements.
 Site considerations such as space and height access, noise and
environmental limitations.

DEWATERING
• Dewatering is more applicable to the problem of sludge disposal from
wastewater treatment of plants .
• But may also be applicable in some cases to municipal/industrial waste
problems.
• When drying beds, lagoons or spreading on land are not feasible, other
mechanical means of dewatering are used.
• The emphasis in the dewatering operation is often on reducing the
liquid volume.
• Once dewatered, the sludge can be mixed with other solid waste, and
the resulting mixture can be:
 Buried in a landfill.
 Incinerated to reduce volume .
 Used for the production of recoverable by-products;
 Used for production of compost.

 Centrifugation and filtration are the two common methods for
the dewatering of sludge.
 Sludges with solid content of a few percent can be thickened to
about 10 – 15% in centrifugation
 And about 20 – 30% in pressure filtration or vacuum
filtration.

SUMMARY
• We discussed various processing techniques that are
used in SWM system to improve the efficiency of
operation, recovery of resources, i.e., usable
materials, and recovery of conversion product and
energy.
• We began our discussion with the importance of
processing techniques and the nature of equipment
involved for the purpose.

SUMMARY
• Subsequently, we discussed mechanical volume and size
reduction techniques and touched upon chemical
volume reduction.
• We also studied about some component separation
techniques (air separation, magnetic separation,
screening, etc.).
• So, now we have closed the unit with a discussion on
drying and dewatering, i.e., the processing techniques
used for removing varying amounts of moisture
present in solid wastes.

METHODS OF DISPOSALS
These are the following methods for
disposal of the solid waste.
• LAND FILLS
• INCINARATION
• BIOLOGICAL REPROCESSING
• RECYCLING
• OCEAN DUMPING
• PLASMA GASSIFICATION

LAND FILL
• It is the most traditional method of waste
disposal.
• Waste is directly dumped into disused quarries,
mining voids or borrow pits.
• Disposed waste is compacted and covered with
soil to prevent vermin and wind-blown litter.
• Gases generated by the decomposing waste
materials are often burnt to generate power.
• It is generally used for domestic waste.

ADVANTAGES
• Landfill site is a cheap waste disposal option for the
local council.
• Jobs will be created for local people.
• Lots of different types of waste can be disposed of by
landfill in comparison to other waste disposal
methods.
• The gases given off by the landfill site could be
collected and used for generating power.

DISADVANTAGES
• The site will look ugly while it is being used for landfill.
• Dangerous gases are given off from landfill sites that cause
local air pollution and contribute to global warming.
• Local streams could become polluted with toxins seeping
through the ground from the landfill site.
• Once the site has been filled it might not be able to be used for
redevelopment as it might be too polluted.

LAND REQUIRED FOR DISPOSAL OF
MSW

EMMISION OF METHANE FROM LANDFILL

INCINERATION
• Incineration is a waste treatment process that involves the
combustion of solid waste at 1000C.
• waste materials are converted into ash, flue gas, and heat.
• The ash is mostly formed by the inorganic constituents of
the waste and gases due to organic waste.
• the heat generated by incineration is used to generate
electric power.

ADVANTAGES
• Minimum of land is needed compared to other disposal
methods.
• The weight of the waste is reduced to 25% of the initial value.
• No risk of polluting local streams and ground waters as in
landfills.
• Incineration plants can be located close to residential areas.
• Gases are used to generate power.

DISADVANTAGES
• Expensive
• Required skilled labor.
• The chemicals that would be released into the air
could be strong pollutants and may destroy ozone
layer (major disadvantage).
• high energy requirement

INCINERATION PLANT OBERHAUSEN, GERMANY

OCEAN DUMPING
• Ocean dumping is the dumping or placing of materials in the
ocean, often on the continental shelf.
• A wide range of materials is involved, including garbage,
construction and demolition debris, sewage sludge, dredge
material, waste chemicals, and nuclear waste.
• Sometime hazardous and nuclear waste are also disposed but
these are highly dangerous for aquatic life and human life also.

ADVANTAGES
• Convenient
• Inexpensive
• Source of nutrients for fishes and marine
mammals.
• Vast amount of space is available.
• All type of wastes are disposed.

DISADVANTAGES
• There are three main direct public health risks from ocean dumping:
(1) Occupational accidents, injuries, and exposures
(2) Exposure of the public to hazardous or toxic materials washed up
on beach sand.
(3) Human consumption of marine organisms that have been
contaminated by ocean disposal.
(4) Highly dangerous for aquatic life.

BIOLOGICAL REPROCESSING
• Materials such as plants, food scraps, and paper products can
be decomposed into the organic matter.
• The organic matter that is produced from this type of recycling
can then be used for such things as landscaping purpose or
agricultural uses.
• Usually this method of recycling is done by putting the
materials in a container and let to stay there until it
decomposes.

RECYCLING
• It is basically processing or conversion of a waste item into
usable forms.
• Recyclable materials include many kinds of glass, paper,
metal, plastic, textiles, and electronics.
• But recycling is not a solution to managing every kind of
waste material.
• For many items like plastic bags, plastic wrap, yogurt cups,
margarine container etc. recycling technologies are unavailable
or unsafe.

ADVANTAGES
• Reduction of air and water pollution.
• Reduction in the release of harmful chemicals and greenhouse
gases from rubbish.
• Saves space required as waste disposal landfill.
• Reduce financial expenditure in the economy.
• It helps in conserving a lot of energy resources like petroleum
and coal deposits.

SAVING THROUGH RECYCLING
• When aluminum is recycled - considerable saving in
cost.
• Making paper from waste saves 50% energy.
• Every tone of recycled glass saves energy equivalent
to 100 liters of oil.
• Recycling about 54 kg of newspaper will save one
tree.

PLASMA GASIFICATION
• Plasma gasification is another form of waste management.
• Plasma is a primarily an electrically charged or a highly
ionized gas. Lighting is one type of plasma which produces
temperatures that exceed 12,600 °F.
• With this method of waste disposal, a vessel uses characteristic
plasma torches operating at +10,000 °F which is creating a
gasification zone till 3,000 °F for the conversion of solid or
liquid wastes into a syngas.

• During the treatment solid waste by plasma gasification, the
waste’s molecular bonds are broken down as result of
the intense heat in the vessels and the elemental components.
• Thanks to this process, destruction of waste and dangerous
materials is found. This form of waste disposal provides
renewable energy and an assortment of other fantastic benefits.

WHAT IS PLASMA?
• Fourth state of matter.
• It is an ionized gas at high
temperature, capable of
conducting current due to
free electrons.
• Created by applying an
electric arc to a low-
pressure gas.
• Lightning is an example
from nature.

PLASMA TORCHES
• Consists of a tungsten rod
(cathode) and a water-cooled
copper (anode).
• Shaped in the form of a nozzle.
• Gas is introduced in the
electrode gap and a dc arc is
established between the
electrodes to create plasma.

COMPOSTING
• Composting is the controlled biological
decomposition of organic matters, such as food and
yard wastes, into humus, a soil-like material.
• Composting is nature's way of transforming organic
waste (such as kitchen vegetable scraps, soiled paper
and yard trimmings) into new soil.

The role of composting in MSW disposal
• The composting methods can potential deal up to 25% of the
MSW (U.S., 2000)
• The suitable (such as kitchen vegetable scraps, soiled paper
and yard trimmings) materials can be turned into compost in 8
to 24 weeks;

Source reduction
Definition
 Source reduction, also known as waste prevention
or pollution prevention, is the elimination or
reduction of waste before it is created.
 It involves the design, manufacture, purchase or use
of materials and products to reduce the amount or
toxicity of what is thrown away.

The need of source reduction
(1) Shortage of suitable landfill space; In many areas,
no suitable land is available for landfills
development.
(2) The development of new landfill site is expensive;
New landfills often resisted due to public concerns
over groundwater contamination, odors, and truck
traffic;

• The most effective way to solve the problem is by reducing
waste in the first place,i.e. Stopping waste before it
happens.
• Source reduction first, recycling and composting second,
and disposal in landfills or waste combustors last.

THE PRACTICE IN SOURCE REDUCTION
• Purchasing long-lasting goods;
• Seeking products and packaging that are as free of
toxics as possible;
• Redesigning products to use less raw material in
production, have a longer life, or be used again after
its original use;
• Reusing items is another way to stop waste at the
source;

Benefits of source reduction and reuse
• Saving natural resources;
• Reducing toxicity of waste;
• Reducing costs;

Summary
• The lifestyle should be changed;
• The degree to which any method will be use will
depend on economics, changes in technology, and
citizen awareness and involvement.

Bioremediation :
Is defined as the process whereby organic
wastes are biologically degraded under
controlled conditions to levels below
concentration limits established by
regulatory authorities.

• Bioremediation makes effective better
approach possible. Either by destroying
or render them harmless using natural
biological activity.

• Relatively low cost
• Low technology techniques
• Generally has general public acceptance
• Can often be carried out on site –no transport
Drawbacks
• May not be effective on all contaminants
• Time duration – relatively long
• Expertise required to design and implement –
although not technically complex

Qualities of :
• Qualities of Microorganisms Environment
• Able to degrade hydrocarbons
• Able to fix nitrogen No secondary/side effects
• Presence of accessory nutrients (N P K Fe)
• Absence of heavy metals Adequate O2, Temperature,
pH

SOLID WASTE MANAGEMENT
HIERARCHY

SUMMARY
Solid waste is hazardous to health so it has to
be handled carefully and disposed properly in
order to protect our health and to maintain
good environment.

Bio-Medical waste
Definition :
Acc to bio medical waste rules ,1998 of India“ bio-medical waste” means
any waste which is generated during the diagnosis, treatment or
immunization of human beings or animals or in research activities
pertaining there to or in the production or testing of bio medicals.
Any unwanted residual material which cannot be discharged directly, or after
suitable treatment can be discharged in the atmosphere or to a receiving water
source, or used for landfill is waste. (Wilson, 1981)

Sources of health care waste
 Government/private hospitals
 Nursing homes
 Physician/dentist office or clinic
 Dispensaries
 Primary health care centers
 Medical research and training centers
 animal./slaughter houses
 labs/research organizations
 Vaccinating centers
 Bio tech institutions/production units

Definition
• Hospital waste: refers to all waste, biological or non biological, that is
discarded and is not intended for further use .
• Medical waste: refers to materials generated as a result of patient
diagnoses, treatment, immunization of human beings or animals .

Definition
• Infectious waste: are the portion of medical waste that could
transmit an ‘infectious disease’.
• Pathological waste : waste removed during surgery/ autopsy or
other medical procedures including human tissues, organs, body parts,
body fluids and specimens along their containers.

MAGNITUDE OF THE PROBLEM
 GLOBALLY- Developed countries generate 1 to 5 kg/bed/day
 Developing countries: meager data, but figures are lower.
1-2kg/pt./day
 WHO Report: 85% non hazardous waste
: 10% infective waste
: 5% non-infectious but hazardous.
(Chemical, pharmaceutical and radioactive)
 INDIA:-No national level study
- local or regional level study shows hospitals
generate roughly 1-2 kg/bed/day

WASTE
CATEGORY
TYPE OF WASTE
TREATMENT AND
DISPOSAL OPTION
Category No. 1
Human Anatomical Waste (Human tissues,
organs, body parts)
Incineration@ / deep burial*
Category No. 2
Animal Waste
(Animal tissues, organs, body parts,
carcasses, bleeding parts, fluid, blood and
experimental animals used in research, waste
generated by veterinary hospitals and
colleges, discharge from hospitals, animal
houses)
Incineration@ / deep burial*
Category No. 3
Microbiology & Biotechnology Waste
(Wastes from laboratory cultures, stocks or
specimen of live micro organisms or
attenuated vaccines, human and animal cell
cultures used in research and infectious
agents from research and industrial
laboratories, wastes from production of
biologicals, toxins and devices used for
transfer of cultures)
Local autoclaving/
microwaving / incineration@
CATEGORIES OF BIOMEDICAL WASTE

Category No. 4
Waste Sharps (Needles, syringes, scalpels,
blades, glass, etc. that may cause puncture
and cuts. This includes both used and
unused sharps)
Disinfecting (chemical
treatment@@ / autoclaving
/ microwaving and
mutilation / shredding
Category No. 5
Discarded Medicine and Cytotoxic drugs
(Wastes comprising of outdated,
contaminated and discarded medicines)
Incineration@ / destruction
and drugs disposal in
secured landfills
Category No. 6
Soiled Waste (Items contaminated with
body fluids including cotton, dressings,
soiled plaster casts, lines, bedding and other
materials contaminated with blood.)
Incineration@ / autoclaving
/ microwaving
Category No. 7
Solid Waste (Waste generated from
disposable items other than the waste sharps
such as tubing, catheters, intravenous sets,
etc.)
Disinfecting by chemical
treatment@@ / autoclaving
/ microwaving and
mutilation / shredding

Problems Related to bio medical waste in India

Classification of health care waste
INFECTIOUS WASTE
 Lab cultures
 Waste from isolation wards
 Tissues(swabs)
 Materials/equipments of infected patients

Pathological waste
• Excreta
• Human tissues/fluids
• Body parts
• Blood or body fluids

Sharp waste
 Needles
 Infusion Sets
 Scalpels
 Knives Blades
 Broken Glass

Pharmaceutical waste
• Expired Pharmaceuticals
• Contaminated Pharmaceuticals
• Banned Pharmaceuticals

Genotoxic waste
 Waste Containing Cytotoxic Drugs(often Used
In Cancer Theraphy)
 Genotoxic Chemicals
CHEMICAL WASTE
 Lab reagents
 Film developer
 Expired disinfectants
 Expired solvents
WASTE WITH HIGH CONTENT OF HEAVY
METALS
 Waste with high content of heavy metals
 Batteries
 Broken thermometers
 Blood pressure guages etc

PRESSURIZED CONTAINERS
 Gas cylinders
 Gas catridges
 Aerosol cans
RADIOACTIVE WASTE
 Radiotherapy/lab research liquids
 Contaminated glass wares, packages,
absorbent papers

Hospital waste disposal
202
• Hospital waste management is a
part of hospital hygiene and
maintenance activities. In fact
only 15% of hospital waste i.e.
"Biomedical waste" is
hazardous, not the complete.
• But when hazardous waste is
not segregated at the source of
generation and mixed with
nonhazardous waste, then 100%
waste becomes hazardous

Treatment and Disposal Methods of
Hospital Waste
203

Bio =
Biodiversity
What does “Bio” means?

Biodiversity
Diversity = Variety
What does “Diversity” means?

INTRODUCTION
The term Biodiversity was first coined by Walter G. Rosen in
1986.
The biosphere comprises of a complex collections of innumerable
organisms, known as the Biodiversity, which constitute the
vital life support for survival of human race.
Biological diversity, abbreviated as biodiversity, represent the
sum total of various life forms such as unicellular fungi,
protozoa, bacteria, and multi cellular organisms such as plants,
fishes, and mammals at various biological levels including
gens, habitats, and ecosystem .

There are three types of biodiversity
 Diversity of Species
 Diversity of Ecosystem
 Diversity of Genes

DISTRIBUTION OF BIODIVERSITY
 Flora and fauna diversity
depends on-
 Climate
 Altitude
 Soils
 Presence of other species
 Most of the biodiversity
concentrated in Tropical region.
 BIODIVERSITY HOTSPOTS:
 A region with high biodiversity
with most of spices being
Endemic.
 India have two Biodiversity
Hotspots- East Himalayan
Region and Western Ghat.

BENEFITS OF BIODIVERSITY
Consumptive value:
 Food/Drink
 Fuel
 Medicine
 Better crop varieties
 Industrial Material
Non-Consumptive Value:
 Recreation
 Education and Research
 Traditional value

Ecological services:
Balance of nature
Biological productivity
Regulation of climate
Degradation of waste
Cleaning of air and water
Cycling of nutrients
Control of potential pest and disease causing species
Detoxification of soil and sediments
Stabilization of land against erosion
Carbon sequestration and global climate change
Maintenance of Soil fertility

THREATS TO BIODIVERSITY
Natural causes:
 Narrow geographical area
 Low population
 Low breeding rate
 Natural disasters
Anthropogenic causes:
 Habitat modification
 Overexploitation of selected
species

 Pollution
 Hunting
 Global warming and climate
change
 Agriculture
 Domino effect

RECENT ISSUES ON BIODIVERSITY
 Some 75 per cent of the genetic diversity of crop
plants been lost in the past century.
 Some scientists estimate that as many as 3 species per hour are
going extinct and 20,000 extinctions occur each year.
 Roughly one-third of the world’s coral reef systems have been
destroyed or highly degraded.
 About 24 per cent of mammals and 12 per cent of bird species are
currently considered to be globally threatened.
 More than 50 per cent of the world’s wetlands have been drained,
and populations of inland water and wetland species have declined
by 50per cent between 1970 and 1999.

CONSERVATION OF BIODIVERSITY
 Biodiversity inventories
 Conserving Biodiversity in protected Habitats-
• In situ conservation
• Ex situ conservation
 Seed Bank, Gene Bank, Pollen Bank, DNA
Bank
Gene Bank
zoo
Bandhavgarh National Park

 Restoration of Biodiversity
 Imparting Environmental Education
 Enacting, strengthening and enforcing Environmental
Legislation
 Population Control
 Reviewing the agriculture practice
 Controlling Urbanization
 Conservation through Biotechnology

BIODIVERSITY IN INDIA
Categories No. of Indian
Species
% of Indian species
Evaluated
Species Threatened
In India
Mammals 386 59 41%
Birds 1219 _ 7%
Reptiles 495 73 46%
Amphibians 207 79 57%
Freshwater Fish 700 46 70%

CONCLUSION
Biodiversity is our life. If the Biodiversity got lost at
this rate then in near future, the survival of human
being will be threatened. So, it is our moral duty to
conserve Biodiversity as well our Environment. Long-
term maintenance of species and their management
requires co-operative efforts across entire landscapes.
Biodiversity should be dealt with at scale of habitats or
ecosystems rather than at species level.

For more details, contact me
over LinkedIn
https://in.linkedin.com/in/smitashukla1309

Bioresource and waste management

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