MAIN EXAM
KIGALI INSTITUTE OF SCIENCE AND TECHNOLOGY
INSTITUT DES SCIENCES ET TECHNOLOGIE DE KIGALI
Avenue de l'Armée, B.P. 3900 Kigali, Rwanda
INSTITUTE EXAMINATIONS-SEM:II
ACADEMIC YEAR 2012-2013
FACULTY OF ENGINEERING
DEPARTMENT: CIVIL
YEAR: 3
SEMESTER: II
MODULE:WEE
DATE:
ENGINEERING & ENVIRONMENTAL TECHNOLOGY
GROUP: WEE
3323 Pollution and Solid Waste Management
/ /2013
TIME:
2hours
MAXIMUM MARKS =
60
INSTRUCTIONS
1. This paper contains FOUR (4) questions.
2. Answer THREE (3) Questions:
Question ONE (1) from Section “A” is Compulsory and Answer any TWO (2) from
Section “B”
3. All questions carry equal marks.
4. No written materials allowed.
5. Do not forget to write your Registration Number.
6. Write all your answers in the booklet provided
7. Do not write any answers on this questions paper.
8. Start the questions in NEW pages
SECTION A
Question One:
/20 Marks
a) What is meant by environment pollution?/4marks
b) i. What is air pollution? /2marks
ii. What Causes air Pollution?/2marks
iii. What are the consequences of air pollution?/2 Marks
c) Briefly describe the solid waste streams
/10Marks
SECTION B
Question Two:
/20 Marks
a) The Clean Air Act of 1970 mandated the setting of standards for four of the primary
pollutants. Give those four primary pollutants. /4 Marks
b) Describe how Polluter pays principles and Solid Waste Hierarchy can be employed as
Concepts to Solid Waste Management. /10 Marks
c) State six Health Effects of pollution emissions. /6Marks
Question Three:
/20 Marks
a) What are the kinds of wastes? /4 Marks
b) What do you understand by biomedical waste? Categorize biomedical waste and determine
its management./10Marks
c) What are the concerns associated with open burning./6Marks
Question Four:
/20 Marks
a) Describe how Integrated Solid waste Management (ISWM) system can be employed as
an overall solid waste management approach to creating sustainable systems that are
economically affordable, socially acceptable and environmentally effective./10Marks
b) Give account definite of the consequences of poor waste management in Kigali City?
/10Marks
 GOOD LUCK
SECTION A
Question One:
/20 Marks
a) What is meant by environment pollution? /4Marks
R/:


Environment pollution can be made by human activity and by natural forces as well.1Mark
Environmental pollution is tangled with the unsustainable anthropogenic activities, resulting
in substantial public health problems such as:
i)
cancer, ii) birth defects, and iii) asthma, many of which may be associated with
environmental exposures.3Marks
b) i. What is air pollution? /2 Marks
ii. What Causes air Pollution? /2 Marks
iii. What are the consequences of air pollution?/2Marks
R/: Air pollution may be defined as the presence in the air (outdoor atmosphere) of one or more
contaminants or combinations thereof in such quantities and of such durations as may be or tend to
be injurious to human, animal or plant life, or property, or which unreasonably interferes with the
comfortable enjoyment of life or property or conduct of business.2Marks
One of the main causes of air pollution is the release of carbon dioxide into the atmosphere, this
happens because of Deforestation and fossil fuel burning. Sulfur dioxide is another air polluter and is
released into the atmosphere by the burning of sulfur containing compounds of fossil fuels.2Marks
The consequences of air pollution: CO2 is a good transmitter of sunlight, but it also partially
restricts infrared radiation going back from the earth into space, which produces the so-called
greenhouse effect that prevents a drastic cooling of the Earth during the night. 2Marks
c) Briefly describe the solid waste streams/10Marks
R/:WASTE STREAMS
Municipal
Waste management is the collection, transport, processing, recycling or disposal, and monitoring of
waste materials. Waste management is also carried out to recover resources from it. Waste
management can involve solid, liquid, and gaseous substances, with different methods and fields of
expertise for each.
Waste reduction methods: An important method of waste management is the prevention of waste
material being created, also known as waste reduction. Methods of avoidance include reuse of
second-hand products and repairing broken items instead of buying new.2Marks
Recycling: Items that are usually composed of a single type of material are relatively easy to recycle
into new products i.e. paper and plastics. The recycling of complex products (such as computers and
electronic equipment) is more difficult, due to the additional dismantling and separation
required.2Marks
Composting: Waste materials that are organic in nature, such as plant material, food scraps, and
paper products, can be recycled using biological composting and digestion processes to decompose
the organic matter. The resulting organic material is then recycled as mulch or compost for
agricultural.2Marks
Landfill: Disposing of waste in a landfill involves burying the waste. A properly-designed and wellmanaged landfill can be a hygienic and relatively inexpensive method of disposing of waste
materials.2Marks
Incineration: Incineration is a disposal method that involves combustion of waste material.
Incineration and other high temperature waste treatment systems are sometimes described as
"thermal treatment". Incinerators convert waste materials into heat, gas, steam, and ash. 2Marks
SECTION B
Question Two:
/20 Marks
a) The Clean Air Act of 1970 mandated the setting of standards for four of the primary
pollutants. Give those four primary pollutants. /4 Marks
R/:
 particulates, 1Mark
 sulfur dioxide,1Mark
 carbon monoxide, 1Mark
 Nitrogen.1Mark
b) Describe how Polluter pays principles and Solid Waste Hierarchy can be employed as
Concepts to Solid Waste Management. /10 Marks
R/: Solid waste management concepts
There are a number of widely-used concepts about waste management:
Solid Waste hierarchy: 5Marks
 The waste hierarchy refers to the "3 Rs" reduce, reuse and recycle, which classify waste
management strategies according to their desirability in terms of waste minimization.3
Marks
 The solid waste hierarchy remains the cornerstone of most waste minimization strategies.1
Mark
 The aim of the waste hierarchy is to extract the maximum practical benefits from products
and to generate the minimum amount of waste.1Mark
Polluter pays principle: 5Marks
The Polluter Pays Principle is a principle where the polluting party pays for the impact caused to the
environment. With respect to waste management, this generally refers to the requirement for a waste
generator to pay for appropriate disposal of the waste.Education and awareness in the area of waste
and waste management is increasingly important.
c) State six Health Effects of pollution emissions. /6Marks
R/:
 Aggravation of respiratory and cardiovascular disease; 1Mark
 decreased lung function; 1Mark
 increased frequency and severity of respiratory symptoms such as difficulty breathing and
coughing;1Mark
 increased susceptibility to respiratory infections; 1Mark


effects on the nervous system, including the brain, such as IQ loss and1Mark
Impacts on learning, memory, and behavior; cancer; and premature death.1Mark
Question Three:
/20 Marks
a) What are the kinds of wastes? /4 Marks
R/:Kinds of Wastes
 Solid wastes: domestic, commercial and industrial wastes especially common as codisposal of wastes. Examples: plastics, styrofoam containers, bottles, cans, papers, scrap iron,
and other trash.2Marks
 Liquid Wastes: wastes in liquid form. Examples: domestic washings, chemicals, oils, waste
water from ponds, manufacturing industries and other sources. 2Marks
b) What do you understand by biomedical waste? Categorize biomedical waste and
determine its management. /10Marks
R/: Biomedical waste: 1 Mark
Biomedical waste consists of solids, liquids, sharps, and laboratory waste that are potentially
infectious or dangerous. It must be properly managed to protect the general public, specifically
healthcare and sanitation workers who are regularly exposed to biomedical waste as an occupational
hazard.
The following is a list of materials that are generally considered biomedical waste: 4 Marks
Solids: Catheters and tubes, disposable gowns and masks, disposable tools, such as some scalpels
and surgical staplers, medical gloves, surgical sutures and staples, and wound dressings. 1 Mark
Liquids: blood, body fluids and tissues, cell, organ, and tissue cultures. 1 Mark
Sharps: blades, razors, scalpel blades, needles, and syringes. 1 Mark
Laboratory waste: animal carcasses, hazardous chemicals.1 Mark
Management: 5Marks
 Sorting of medical wastes in hospital: At the site where it is generated, biomedical waste is
placed in specially-labelled bags and containers for removal by biomedical waste
transporters. 1 Mark
 Other forms of waste should not be mixed with biomedical waste as different rules apply to
the treatment of different types of waste. 1 Mark
 Biomedical waste is treated by any or a combination of the following methods: incineration
or steam, chemical, or microwave sterilization. Any tools or equipment that come into
contact with potentially infectious material and are not disposable or designed for single-use
are sterilized in an autoclave.3 Marks
c) What are the concerns associated with open burning.
/6Marks
R/:
 Open burning has many negative effects on both human health and the environment. This
uncontrolled burning of garbage releases many pollutants into the atmosphere. 2Marks
 These include dioxins, particulate matter, polycyclic aromatic compounds, volatile organic
compounds, carbon monoxide, hexachlorobenzene and ash. All of these chemicals pose
serious risks to human health. 2 Marks
 The harmful effects of open burning are also felt by the environment. This process releases
acidic gases such as the halo-hydrides; it also may release the oxides of nitrogen and carbon.
Nitrogen oxides contribute to acid rain, ozone depletion, smog and global warming.2Marks
Question Four:
/20 Marks
a) Describe how Integrated Solid waste Management (ISWM) system can be employed
as an overall solid waste management approach to creating sustainable systems that
are economically affordable, socially acceptable and environmentally effective.
/10Marks
 Integrated Solid Waste Management (ISWM) takes an overall approach to creating
sustainable systems that are economically affordable, socially acceptable and
environmentally effective.2 Marks
 An integrated solid waste management system involves the use of a range of different
treatment methods, and key to the functioning of such a system is the collection and sorting
of the waste. 2 Marks
 It is important to note that no one single treatment method can manage all the waste materials
in an environmentally effective way. 2 Marks
 Thus all of the available treatment and disposal options must be evaluated equally and the
best combination of the available options suited to the particular community chosen.2 Marks
 Effective management schemes therefore need to operate in ways which best meet current
social, economic, and environmental conditions of the municipality.2 Marks



b) Give account definite of the consequences of poor waste management in Kigali City?
/10Marks
Infrastrural destruction: Garbage is dumped hazard in manholes of drainage sewage
systems leading to blockages of sewages pipes causing floods of sewage across the roads and
blockage of the toilets rendering them nonfunctional. Blockage of manholes and roads side
gutters lead to the ponding effect and consequential flooding of the city roads. These attract
repairs and maintenance that disrupts many activities. 3 Marks
Contamination of water bodies: Most of the garbage dumping is done in wetlands
including Kigali City. And these wetlands are a major source of drinking water for Kigali
Population. The percolating leachates from the garbage into the soil often find their way into
the underground water table and protected springs.3 Marks
Sanitation and Health: Open dumping is the mode of garbage disposal in Kigali City as
traditional method. It is scenery of flies, rodents and others vectors that scramble for
decomposing. This method of waste management exposes public to danger of various
communicable diseases such as diarrhea, cholera, dysenteries, etc. Some of the pathological
wastes are contaminated in the wastes and are eminent sources of epidemiological
effects.4Marks
 THANK YOU