Environmental Engineering II (CE 3233)...Environmental Engineering II (CE 3233) Chapter: Solid Waste...

Environmental Engineering II (CE 3233)

Chapter: Solid Waste Management

Reference: 1. Water Supply and Sanitation by F. Ahmed and M.M MujiburRahman (ITN) – Part II Chapter 14

2. Environmental Engineering by Peavy, Rowe and Tchobanoglous

Lecture prepared by

Md Nuruzzaman

Lecturer, Department of Civil Engineering

Bangladesh Army University of Engineering and Technology (BAUET)

E-mail: [email protected], [email protected]

Phone: +8801719456829

mailto:[email protected]


Solid Wastes

Solid waste can be defined as useless, unwanted and discarded materials

coming from production and consumption.

Solid waste management

It encompasses all aspects concerning waste generation, onsite handling

and storage, collection, transportation, treatment, reuse/recycle and final

disposal.

Types of solid waste

1.Municipal waste

2. Industrial waste

3.Hazardous waste

Solid Waste Management

Municipal Waste

Solid wastes that are generated in residential and commercial

installation are termed as municipal waste. It primarily include food

waste, rubbish, ashes and residue, demolition and construction

wastes, street sweeping etc.

Industrial waste

Solid wastes that are derived as by-products from industrial operations

and manufacturing process, or discarded as useless.


Hazardous waste

Waste that pose a substantial danger immediately or over a period of

time to human, plant, or animal life are classified as hazardous waste.

Waste is grouped as hazardous waste if it exhibits any of the following

characteristics:

1. Ignitability

2.Corrosivity

3.Reactivity

4.Toxicity


Hazardous waste

Hazardous wastes are classified into 5 groups

1.Radioactive substances

2.Chemicals

3.Biological wastes

4.Flammable wastes

5.Explosives

Main source of hazardous biological waste are hospitals and

biological research facilities and industries.


Definitions

Garbage/food waste

These are the putrescible wastes primarily resulting from food products.

•They include cooked and uncooked vegetables, fruits and other food

leftovers

•decompose quickly, resulting in unpleasant odors

•Need immediate attention for handling and disposal

Rubbish

It includes both combustible and non-combustible substances such as

paper, cans, broken glass, wood, cardboard, scrap metals etc.


Definitions

Residential wastes

Waste generated in houses and apartments- may include paper,

cardboard, food cans, plastics, food waste, glass containers, garden

waste etc.

Commercial waste

Solid waste generated in commercial and service establishments such

as office buildings, hotels and restaurants, shops, market places etc.

Demolition and construction wastes

Waste produced from demolition and or construction of buildings roads

and other structures—include brick bat, concrete pieces , sand,

electrical wires glasses pipes etc.


Definitions

Agricultural waste

Waste generated from agricultural activities such as growing plants

and raising animals – include plant stalks, leaves, husk and animal

manure.

Resource recovery

Extraction of economically useable materials and energy from wastes.

Re-use

Reclamation of material in its end-use form and its subsequent use in

the same form. Example—milk or soft drink bottles (i.e. glass) that

make several trips from the bottler to the consumers.


Definitions

Recycling

Reprocessing of wastes to recover an original raw material. Example

– used news papers are recycled to make new paper.

Material conversion

Utilization of wastes in a different form of material such as compost

from newspaper or paving material from auto tires.

Energy recovery

Capturing the heat value from organic wastes, either by direct

conversion or by first converting it into an intermediate fuel products.



Effects of solid waste mismanagement

Specific problems associated with inadequate solid wastemanagement are:

1. foul odour near waste storage bins that are not emptied regularlyor not washed and disinfected periodically;

2. blocking of drainage systems resulting in wastewater overflowdue to indiscriminate dumping of solid wastes;

3. soiled streets due to inadequate street sweeping, uncontrolledlittering and dumping of domestic wastes.

4. Spreading of wastes by scavenging birds and animals nearuncollected garbage bins, other collection points and uncontrolleddumping sites;


Effects of solid waste mismanagement

5. pollution of surface water bodies and groundwater) by leachatefrom solid wastes disposed of without proper planning anddesign;

6. land pollution from untreated and inadequately treated industrialwastes containing toxic substances and heavy metals;

7. indiscriminate disposal of hospital wastes that containpathogenic organisms which may lead to spread of infectiousdiseases;

8. transmission of vector-borne diseases;

9. health risks to solid waste workers and scavengers.


Functional Elements of SWM



Waste generation

Involves those activities in which materials are identified as no longer

being of value and therefore are thrown away as useless or gathered

together for disposal.

On-site handling and storage

Activities associated with the handling, storage and processing of solid

wastes at or near the point of generation.

Collection

Activities associated with the gathering of solid wastes and hauling of the

wastes after collection to a location where the collection vehicle is

emptied.



Transfer and transport

Activities associated with the transfer of wastes from the smaller

collection vehicle to larger transport equipment and subsequent

transport of the waste, usually over a long distance, to the disposal site.

Processing and recovery

Those techniques, equipment and facilities used both to improve the

efficiency of the other functional elements and to recover usable

materials, conversion products or energy from solid wastes.



Final disposal

Activities associated with ultimate disposal of solid wastes including

those wastes collected and transported directly to a landfill site


Factors affecting the generation rate of solid wastes:

1. Geographic location

2. Season of the year

3. Collection frequency

4. Population characteristics

5. Public attitudes

6. Extent of salvage and recycling

7. Legislation


Physical Composition of Solid Waste

Physical composition of solid waste involves the followings:

1. Identification of the individual components

2. Analysis of particle size

3. Moisture content

4. Density of solid waste

• Physical composition

1.Individual Components


2.Particle size

The size of the component materials in solid wastes is of importance in

the recovery of materials, especially with mechanical means such as

trommel screens and magnetic separators.

3.Moisture Content

It is usually expressed as the mass of moisture per unit of wet or dry

material. The wet-mass moisture content is expressed as follows:

Moisture content(%)=(a-b)X100/a,

Where a= Initial mass of sample as delivered

b=Mass of sample after drying


3.Moisture Content


4. Density

Density of solid waste vary with

geographic location, season of

the year and length of storage.


• Energy content

Chemical composition is important in evaluating alternative processing

and energy recovery option.

1.Proximate analysis

▪ Moisture(loss at 1050 C for 1 hr)

▪ Volatile matter(additional loss on ignition at 9500 C)

▪ Ash (residue after burning)

▪ Fixed carbon(remainder)


• Energy content

2. Ultimate analysis– percentage of C, H, O, N, S, and ash

3. Ash analysis

▪ Flushing point of ash

▪ Ash residue

4. Energy Value

▪ As discarded basis

▪ Dry weight basis

▪ Ash-free dry basis


On-site Storage

Factors that must be considered in the on-site storage of solid wastes

include:

(i) Type of container to be used,

(ii) The container location,

(iii) Public health and aesthetics, and

(iv) The collection methods to be used.


Methods of solid waste collection

• Communal collection

• Block collection

• Curb-side collection

• House to House collection


Classification of solid waste collection systems

• Hauled container system

• Stationary Container System


Hauled container system

Collection system in which the containers used for the storage of wastes

are hauled to the processing, transfer, or disposal site, emptied, and

returned to either their original location or some other location are

defined as hauled container system.

Stationary Container System

Collection system in which the containers used for the storage of wastes

remain at the point of waste generation, except when moved for

collection are defined as stationary collection system.


Solid Waste Transportation

Selection of vehicle should be made depending on the following

considerations;

1. Characteristics of waste

2. Method of collection

3. Types of roads to be served

4. Ease of maintenance and availability of spare parts

5. Cost of operation


Processing of Solid Waste

Purposes of processing solid waste:

1. To improve the efficiency of solid waste management systems;

2. To recover usable materials

3. To recover conversion products and energy


Techniques of processing solid waste management

1. Mechanical volume reduction (compaction)

2. Chemical volume reduction (incineration)

3. Component separation (manual and mechanical)

4. Mechanical size reduction (shredding)

5. Moisture content reduction (drying and dewatering)


Source separation

Source separation may be defined as the setting aside of the recyclable

wastes at their point of generation for segregated collection and

transport.

The primary aim of source separation is to isolate valuable items from

mixed waste stream.


Resource recovery

Resource recovery from mixed waste stream involves the centralized

processing of collected raw wastes to separate out recyclable materials

and to convert the remaining fraction into useful materials or energy

forms.


Options related to resource recovery

1. Re-use of useable items in household wastes, e.g. glass bottles,

metal containers, etc.;

2. Direct application of the wastes on land;

3. Recycling through material recovery processes;

4. Energy recovery through thermal combustion, incineration, etc.;

5. Composting and other chemical or biological processes;


Incineration

Incineration is a process of reducing the combustible portion of the waste

to an inert residue by high temperature burning. The products of

combustion are ash, gases and heat energy. Incineration is used to

sterilize refuse.


Recycling process in Bangladesh

Wastes in Bangladesh are salvaged basically in three steps:

(1) In the first stage, housewives separate refuse of higher market value

such as papers, bottles, fresh containers, old clothes, shoes, etc. and

sell them to street hawkers.

(2) Mostly, children of slum dwellers also known as Tokai carry out the

second stage of salvaging. They collect broken glass, cardboard,

waste papers, plastics, etc. from waste collection bins.

(3) Scavengers at the final disposal sites do the third stage of salvaging

when municipal trucks unload fresh refuse.


Composting

Composting is the process of bacterial conversion of organic solid and

semisolid wastes into compost, which can be handled, stored and

transported without any adverse environmental effect, and can be used

as organic manure for improvement of soil quality and fertility.


Favorable changes induced by Composting to soil

1. Increases organic content of the soil

2. Increases moisture retention capacity

3. Improves aeration at root zone

4. Improves soil texture

5. Increases soil fertility

6. Replenishes micro-nutrients in soils


Factors affecting composting

1. The waste material subjected to composting must be biodegradable.

2. Suitable numbers and types of micro-organisms must be present.

3. The rate and efficiency of composting are dependent on the activity of

micro-organisms.

4. Environmental factors like pH, temperature and presence of oxygen

control the process.

5. The waste must be nutritionally balanced.

6. The presence of toxic substances has adverse effects on the

process.


Basic Composting processOrganic Solid wastes

Salvaging/Packaging

Screening/Sorting

Shredding/pulverizing

Moisture adjustments

Aerobic composting

Maturing

Processing/Bagging

Saleable compost

Salvageable

Non compostable

Water additives

Air

𝐶𝑂2 , Excess air, 𝑁𝐻3

Figure: Flow diagram showing the basic process of aerobic composting


Chemical Constituents Percent by weight

Organic matter 25-50

Carbon 8-50

Nitrogen (as N) 0.4-3.5

Phosphorus(as 𝑃2𝑂3) 0.3-3.5

Potassium as (𝐾2𝑂) 0.5-1.8

Ash 20-60

Calcium(as 𝐶𝑎O) 1.5-7.0


Characteristic of Compost

Control parameters of effective aerobic composting

There are several important parameters which have to be in desirable

conditions for effective aerobic composting to occur at high

temperatures. Some of these parameters are discussed below:

1. Moisture Content

Moisture content should be in the range of 50-60% during the

composting process, the optimum being about 55%. When the

moisture contents drops much below 50%, the composting process

becomes slow.


2. Carbon- nitrogen ratio

An optimum balance between carbon (C) and nitrogen (N) content in

necessary because the bacteria need a minimum supply of nutrients

to survive.

• Bacteria use carbon as an energy source and nitrogen for cell

building.

• The initial carbon –nitrogen ratio is a deciding factor in the speed

at which the decomposition takes place

• The ideal initial ratio is between 30:1 and 35:1 and if it exceeds

50, the time required increases considerably.


2. Carbon- nitrogen ratio

• In solid waste the main source of nitrogen is the

vegetables/ putrescible matter which has a C/N ratio of

about 24:1 and the paper is the main source of carbon.

• Thus the higher the ratio of paper to vegetable/ putrescible

matter, the higher the C/N ratio.


3. Oxygen requirements

• The availability of air is the key to the aerobic process of

composting. It is however very difficult to determine the exact

oxygen requirements because it depends many other factors

such as temperature, moisture content and availability of

nutrients

• A approximate method of monitoring the sufficient oxygen

supply is to check the compost for foul odours. Presence of

foul odours indicate the insufficient supply of oxygen.


4. Temperature:

• Temperature is also the key factor affecting the biological activity.

• The broad range of optimum temperatures for the composting

process, 45-66 ºC helps a large variety of microorganisms to

precipitate in the process.

• Higher temperature for example 60-70 ºC for about 24 hours

should be maintained for pathogen destruction.


5. pH control

• The optimum pH range for most bacteria is between 6.0 and 7.5

• During the initial period (first 2 to 3 days) pH drops to 5.0 or less

and then begins to rise to about 8.5 for the remainder of the

aerobic process

• If the digestion is allowed to become anaerobic the pH will drop to

about 4.5

• To minimize the loss of nitrogen in the form of ammonia gas, pH

should not rise above 8.5


Major considerations for composting of solid wastes in

Bangladesh

• Availability and sustainability of wastes

• Socio-economic conditions

• Technological access

• Marketing for compost

• Affordable prices for farmers

• Environmental legislation and enforcement

• Present disposal cost

• Institutional support


Ultimate disposal methods of solid waste

➢ Sanitary landfilling

➢ Ocean Disposal

➢ Atmospheric disposal

➢ Land farming

➢ Deep-Well Injection

➢ Incineration


Ultimate Disposal

Sanitary Landfill

Sanitary landfill may be defined as the operation in which wastes to be

disposed of are compacted in layers and covered with a layer of earth

at the end of each day’s operation. When the landsill site reaches its

ultimate capacity, a thick final layer of cover material is applied.


Factors for selecting potential landfill sites for disposal of solid

wastes

1. Ensure that sufficient land area is available for disposal of

solid wastes for a reasonable period of time, preferably longer

than one year as for shorter periods the disposal operation is more

expensive

2. Haul distance, route location, local traffic patterns and access

condition must be considered.

3. Soil condition and topography of the site should be considered

so that the cover material is available at or near the landfill site.



wastes

4. Climate conditions e.g., wind patterns and local surface water

hydrology of the area should be considered.

5. It is to be ensured that the movement of the leachate and the

gases from the landfill will not contaminate the groundwater

aquifer.

6. Extreme care is necessary in the operation of the landfill so

that it is environmentally acceptable with respect to noise,

odor, dust and vector control.



wastes

7. The issue of the ultimate use of the completed landfill site is to be

considered prior to the layout and design of the proposed landfill.


Figure: Typical sectional view of a sanitary landfill

Compacted solid waste

CellCell

Final cell

Cell

Daily cover

Final cover on slope face

3:1 typical slope

6 in. intermediate cover

Bench as required

Final cover system

Fin

al li

ftLi

ftLi

ftC

ell h

eig

ht

Lift

he

igh

t

Landfill liner system

Cell-width (variable)


Methods of landfilling

1. Trench method

2. Area method

Trench method- It involves the excavation of a trench. The waste is

then placed into the trench, spread and compacted. The excavated soil

serves as cover material.

Area method- It does not involve excavation of trenches. Instead

wastes are spread and compacted on the surface of the ground. Cover

material is then spread and compacted over the layer of waste. This

area method is suitable on flat and gently sloping land


Aspects for consideration in design and operation of sanitary

landfill

1. Landfill site selection

2. Landfilling methods and operation

3. Design of landfills

4. Gas and Leachate in landfills

5. Operation of landfills

6. Environmental factors


Leachate

Leachate may be defined as liquid that has percolated throughsolid waste and has extracted dissolved or suspendedmaterials from it. In most landfills, the liquid portion of theleachate is composed of the liquid produced from thedecomposition of the wastes and liquid that has entered the landfillfrom external sources, such as surface drainage, rainfall,groundwater, and water from underground springs.


Ocean Disposal of Solid Wastes

The idea of ocean disposal is that the ocean is a gigantic sink, inwhich an infinite amount of pollution of all types can be dumped, hasbeen discarded.

Landfarming

Landfarming is a waste-disposal method in which the biological,chemical, and physical processes that occur in the surface of the soilare used to treat biodegradable industrial wastes.


Deep-Well Injection

Deep-well injection for the disposal of liquid wastes involvesinjecting the wastes deep in the ground into permeable rockformations (typically limestone or dolomite) or underground caverns.



Chapter: Food Sanitation

Reference: Principles of Food Sanitation by Norman G. Marriott Robert and B. Gravani

Lecture prepared by

Md Nuruzzaman




Phone: +8801719456829



Food Sanitation

Food Sanitation

Applied to the food industry, sanitation is the creation and

maintenance of hygienic and healthful conditions.

Sanitation applications refer to hygienic practices designed to

maintain a clean and wholesome environment for food production,

processing, preparation, and storage.

Foodborne Disease

A foodborne disease is considered to be any illness associated withor in which the causative agent is obtained by the ingestion of food.

Food Sanitation

Contamination Sources

1. Red Meat Products

Contamination of meat occurs from the external surface, such ashair, skin, and the gastrointestinal and respiratory tracts.

2. Poultry Products

The processing of poultry, especially defeathering and evisceration,permits an opportunity for the distribution of microorganisms.

3. Seafood Products

Seafoods are excellent substrates for microbial growth and arevulnerable to contamination during harvesting, processing,distribution, and marketing.

Food Sanitation


4. Adjuncts

Ingredients (especially spices) are potential vehicles of harmful orpotentially harmful microorganisms and toxins.

5. Equipment

Contamination of equipment occurs during production, as well aswhen the equipment is idle.

6. Employees

Of all the viable means of exposing microorganisms to food,employees are the largest contamination source

Food Sanitation


7. Air and Water

Contamination can result from airborne microorganisms in foodprocessing, packaging, storage, and preparation areas. Water canalso serve as a source of contamination.

8. Sewage

If raw sewage drains or flows into potable water lines, wells, rivers,lakes, and ocean bays, the water and living organisms such asseafood are contaminated.

Food Sanitation


9. Insects and Rodents

Flies and cockroaches are associated with living quarters, eatingestablishments, and food processing facilities, as well as with toilets,garbage, and other filth. These pests transfer filth from contaminatedareas to food through their waste products; mouth, feet, and otherbody parts; while the regurgitation of filth onto clean food duringconsumption.

Food Sanitation

Potential contamination of food by humans

Food Sanitation

Micro-organisms

A microorganism is a microscopic form of life found on all non-sterilized matter that can be decomposed. These organismsmetabolize in a manner similar to humans through nourishmentintake, discharge of waste products, and reproduction.

Food Sanitation

Types of Micro-organisms related to food sanitation

Three types of microorganisms occur in foods.

(1) Beneficial

Beneficial microorganisms include those that may produce newfoods or food ingredients through fermentation(s) (e.g., yeasts andlactic acid bacteria) and probiotics.

(2) Spoilage

Spoilage microorganisms, through their growth and ultimatelyenzymatic action, alter the taste of foods through flavor, texture, orcolor degradation.

(3) Pathogenic

Pathogenic microorganisms can cause human illness.

Food Sanitation

What causes microorganisms to grow?

1. Temperature

2. Oxygen Availability

3. Relative Humidity

4. Water Availability

5. pH

6. Oxidation-Reduction Potential

7. Nutrient Requirements

8. Inhibitory Substances

9. Interaction between Growth Factors

10.Role of Biofilms

Food Sanitation

Micro-organisms Common to Food

1. Molds (multicellular microorganisms, 30 to 100 μm in diameter)

2. Yeasts (generally unicellular, likely to grow on foods with lowerpH)

3. Bacteria (unicellular microorganisms, 1 μm in diameter)

4. Viruses (infective microorganisms with dimensions that rangefrom 20 to 300 nm)

Food Sanitation

HACCP

The Hazard Analysis Critical Control Point (HACCP) program is apreventive approach of consistent safe food production.

The program focuses on safety and not quality and should beconsidered separate from or a supplement to quality assurance.HACCP was incorporated to guarantee that food used in the U.S.space program would be 100% free of bacterial pathogens.

Food Sanitation

The HACCP concept is divided into two parts:

(1) Hazard analysis and (2) Determination of critical control points.

A hazard is the potential to cause harm to the consumer.

A critical control point (CCP) is an operation or step by whichpreventive or control measures can be exercised that will eliminate,prevent, or minimize a hazard (hazards) that has (have) occurredprior to this point.

Food Sanitation

Food safety and acceptability are most affected by:

(1) contaminated raw food or adjuncts.

(2) improper temperature control during processing and storage(time-temperature abuse).

(3) improper cooling through failure to cool to refrigeratedtemperature within 2 to 4 hours.

(4) improper handling after processing, cross-contamination(between products or between raw and processed foods).

(5) ineffective or improper cleaning of equipment.

(6) failure to separate raw and cooked products.

(7) poor employee hygiene and sanitation practices

Food Sanitation

HACCP Development

1. Facilities: The facilities should be located, constructed, andmaintained according to sanitary design principles

2. Supplier control: Continuing supplier guarantee and supplierHACCP system verification.

3. Specifications: Written specifications for all ingredients,products, and packaging materials.

4. Production equipment: Constructed and installed according tosanitary design principles with preventive maintenance andcalibration schedules that are established and documented.

Food Sanitation

HACCP Development

5. Cleaning and sanitation: All procedures should be written andfollowed.

6. Personal hygiene: All personnel entering the manufacturing areashould follow the requirements for personal hygiene.

7. Training: All employees should receive training in personalhygiene, GMPs, cleaning and sanitation procedures, personalsafety, and their role in the HACCP program.

8. Chemical control: Documented procedures must be adopted toassure the segregation and proper use of nonfood chemicals (i.e.,cleaning compounds, fumigants, pesticides, and rodenticides) in theplant.

Food Sanitation

HACCP DEVELOPMENT

9. Receiving, storage, and shipping: Raw materials and productsshould be stored under sanitary conditions.

10. Traceability and recall: Raw materials and products should belot-coded and a recall system developed so that rapid and completetraces and recalls may be accomplished when necessary.

11. Pest control: An effective past control system should beimplemented.

Food Sanitation

Definitions related to Sanitizing Methods

A sterilant is an agent that destroys or eliminates all forms ofmicrobial life.

A disinfectant is an agent that kills infectious fungi and vegetativebacteria although not necessarily bacterial spores on inanimatesurfaces. Disinfection is a less lethal process than sterilization.

A sanitizer is a substance that reduces, but not necessarilyeliminates microbial contaminants on inanimate surfaces to levelsthat are considered to be safe from a public health standpoint. Asanitizer is effective in destroying vegetative cells

Food Sanitation

Sanitizing Methods

1. Thermal

2. Steam

3. Hot Water

4. Radiation

5. Vacuum/Steam/Vacuum

6. Chemical Sanitizing

Food Sanitation

Desired Sanitizer Properties

The ideal sanitizer should have the following properties:

1. Microbial destruction properties of uniform, broad-spectrumactivity against vegetative bacteria, yeasts, and molds to producerapid kill.

2. Environmental resistance (effective in the presence of organicmatter [soil load], detergent and soap residues, and waterhardness and pH variability)

3. Good cleaning properties

4. Nontoxic and nonirritating properties Water solubility in allproportions

Food Sanitation

Desired Sanitizer Properties

1. Acceptability of odor or no odor

2. Stability in concentrated and use dilution

3. Ease of use

4. Ready availability

5. Inexpensive

6. Ease of measurement in use solution


Chapter: Air Pollution

Reference: Environmental Engineering by Peavy, Rowe and Tchobanoglous(Part 2 – Chapter 7: Air)

Lecture prepared by

Md Nuruzzaman




Phone: +8801719456829



Air Pollution

Definition

Air pollution may be defined as any atmospheric condition in whichsubstances are present at concentrations, above their normalambient levels, to produce measurable adverse effect on man,animal, vegetations or materials.

Air Pollution

Origin

1. Natural

All air contains natural contaminants such as pollen, fungi spores,salt spray and smoke and dust particles from forest fires and naturalvolcanic eruptions. It also contains naturally occurring CO,Hydrocarbon, H2S and CH4 from anaerobic decomposition oforganic matter

2. Anthropogenic (man-made activities)

Use of fossil fuel for heating and cooling, transportation, industry,incineration, etc.

Air Pollution

Types of sources:

1. Mobile Sources/Transportation such as motor vehicle, rail, ship,aircraft, etc

2. Stationary Sources: include utility, industrial and institutional andcommercial facilities. Examples are power plant, heating plant,paper and pulp industry, petroleum, refineries, municipal wastecombustion

3. Area sources: including many individual activities like gasolineservice station, small paint shops, open burning of solid waste,agricultural wastes, cooking, etc.

Air Pollution

Types of sources:

5. Household and commercial waste

6. Agriculture burning

7. Industrial and hazardous waste incineration

8. Miscellaneous

(a) Domestic fuel, wood burning

(b) Forest fire, volcanic eruption, Chemical and materials used indifferent process

Air Pollution

Classification

According to Origin

Primary Pollutants: those emitted directly to the atmosphere andfound there in the form in which they are emitted (Stable form),e.g.SOx, NOx, HC

Secondary Pollutants: derived from the primary pollutants bychemical or photochemical reaction or by hydrolysis or oxidation intothe atmosphere e.g. O3 and Peroxyacetyl Nitrate (PAN)

Air Pollution

Classification

According to Chemical Composition

Organic: HC: Benzene, Methane Hexane, etc

Inorganic: CO, CO2, SOX, NOX, H2S, NH3, etc

According to State of Matter

Gaseous: CO, CO2, NOx, SOx, CH4, etc

Particulate/Aerosole: dust, smoke, fumes, fly ash, etc (specificparticulate size)

Air Pollution

Effects of air pollution

1. Effect on atmospheric properties

Air pollution affect atmospheric properties in the following ways:

I. Visibility reduction

II. Fog formation and precipitation

III. Solar radiation reduction

IV. Temperature and wind direction alteration

V. Possible effect on global climate change

Air Pollution


2. Effects on materials

Air pollutants can affect materials by soiling or chemicaldeterioration

3. Effects on vegetation

Gaseous pollutants enter plant through stomata in the course ofnormal respiration of plant. Once in the leaf, pollutants destroychlorophyll and disrupt photosynthesis.

Air Pollution


4. Effects on human health

Extremely high concentrations of air pollutants (for several hrs/days)can result in serious Air Pollution Episodes, causing significantdeath or injuries.

Air Pollution

Particulates

Particulates are any dispersed matter, solid or liquid, in whichthe individual aggregates are larger than a single smallmolecule (about 0.002 µm in dia) but smaller than about 500µm .

Air Pollution

Mode of formation of Particulates

Dust: small solid particles created by breakdown of largemasses by crushing, grinding or blasting or processing andhandling of materials such as coal, cement or grains. Settleunder the influence of gravity. Size ranges from 1.0 to 10,000µm.

Fumes: solid particles that are formed by the vaporcondensation. Sizes ranges from 0.03 to 0.3 µm.

Air Pollution

Mode of formation of Particulates

Mist, fog: liquid particles or droplets formed by thecondensation of vapor. Mist are usually less than 10 µm indiameter. If the mist concentration is high enough to obscurevisibility, the mist is called a fog.

Smoke: fine, solid particles resulting from incompletecombustion such as coal, wood, tobacco, etc. Size rangesfrom 0.5 to 1.0µm.

Spray: liquid particles formed by atomization of parent liquidssuch as pesticides and herbicides. Size ranges from 10 to1000µm.

Air Pollution

Air quality index (AQI):

AQI is a tool that simplifies reporting air quality to the generalpublic. It has been adopted by USEPA and is used by manycities to report to the public an overall assessment of a givenday’s air quality.

• Color is key for communication

• Ranges from 0 to 500 (no units)

• Provides indicator of the quality of the air and its healtheffects

Air Pollution

AQI Value Air Quality Descriptor Color Code

0-100 Good Green

1001 -200 Unhealthy Orange

201-300 Very Unhealthy Violet

301-500 Extremely Unhealthy Red

Purpose of AQI:

1. To inform people about air quality conditions in a simple format

2. Promote public interest and action to reduce emissions

AQI categories in Bangladesh:


Chapter: Noise Pollution

Reference: Environmental Noise by Pollution Enda Murphy Eoin A. King

Lecture prepared by

Md Nuruzzaman




Phone: +8801719456829



Noise Pollution

Definition

Environmental Noise is unwanted sound created by human activitiesthat is considered harmful or detrimental to human health andquality of life.

Sources of Noise Pollution

• Transportation systems are the main source of noise pollution in urban areas.

• Construction of buildings, highways, and streets cause a lot of noise, due to the usage of air compressors, bulldozers, loaders, dump trucks, and pavement breakers.

• Industrial noise also adds to the already unfavorable state of noise pollution.

• Loud speakers, plumbing, boilers, generators, air conditioners, fans, and vacuum cleaners add to the existing noise pollution.

Noise Pollution

Noise Pollution

Effects of Noise Pollution

Solutions for Noise Pollution

1. Planting bushes and trees in and around sound generating sources is an effective solution for noise pollution.

2. Regular servicing and tuning of automobiles can effectively reduce the noise pollution.

3. Buildings can be designed with suitable noise absorbing material for the walls, windows, and ceilings.

4. Workers should be provided with equipment such as ear plugs and earmuffs for hearing protection.

Noise Pollution

Solutions for Noise Pollution

5. Similar to automobiles, lubrication of the machinery and servicing should be done to minimize noise generation.

6. Soundproof doors and windows can be installed to block unwanted noise from outside.

7. Regulations should be imposed to restrict the usage of play loudspeakers in crowded areas and public places.

8. Factories and industries should be located far from the residential areas.

Noise Pollution


Chapter: Water Pollution

Reference: Environmental Engineering by Anil Kumar De and Amab Kumar De

Lecture prepared by

Md Nuruzzaman




Phone: +8801719456829



Water Pollution

The symptoms of water pollution of any water body/ground waterare:

• Bad taste of drinking water,

• Offensive smells from lakes, rivers and ocean beaches,

• Unchecked growth of aquatic weeds in water bodies(eutrophication),

• Dead fish floating on water surface in river, lake, etc.

• Oil and grease floating on water surface.

Water Pollution

Water Pollutants

The large number of water pollutants are broadly classified underthe categories:

1. Organic pollutants,

2. Inorganic pollutants,

3. Sediments,

4. Radioactive materials and

5. Thermal pollutants.

Water Pollution

Organic Pollutants

These include domestic sewage, pesticides, synthetic organiccompounds, plant nutrients (from agricultural run-off), oil, wastesfrom food processing plants, paper mills and tanneries, etc. Thesereduce dissolved oxygen (D.O.) in water.

Inorganic Pollutants

This group consists of inorganic salts, mineral acids, metals, traceelements, detergents, etc.

Water Pollution

Sediments

Soil erosion, as a matter of natural process, generates sediments inwater. Soil erosion is enhanced 5–10 times due to agricultural and100 times due to construction activities.

Radioactive Materials

Radioactive pollution is caused by mining and processing ofradioactive ores to produce radioactive substances, use ofradioactive materials in nuclear power plants, use of radioactiveisotopes in medical, industrial and research institutes and nucleartests.

Water Pollution

Thermal Pollutants

Coal-fired or nuclear fuel-fired thermal power plants are sources ofthermal pollution. The hot water from these plants is dumped aswaste into nearby lake or river where its temperature rises by about10°C.

Water Pollution

Eutrophication

Sewage and agricultural run-off provide plant nutrients in watergiving rise to the biological process known as eutrophication. Largeinput of fertiliser and nutrients from these sources leads toenormous growth of aquatic weeds which gradually cover the entirewaterbody (algal bloom). This disturbs the normal uses of water asthe water body loses its D.O. and ends up, in a deep pool of waterwhere fish cannot survive.


Chapter: Sustainability of WSS and community management

Reference: Water Supply and Sanitation by M.F. Ahmed and M.M Rahman (ITN) – Part I: Chapter 1 and 2

Lecture prepared by

Md Nuruzzaman




Phone: +8801719456829



Sustainability of WSS

Sustainability

The success of sustainability of a project is achieved when it meets

its objectives and is maintained by its users over a significant period

of time.

Criterion of Sustainability of a water supply system

1. Provides an efficient and reliable services at a level which is

desired.

2. Can be financed or co-financed by the user with limited but

feasible external support and technical assistance.

3. Is being used in an efficient and effective way, without negatively

affecting the environment.

Dimensions of sustainability

1. the user community wanting an efficient and reliable service

2. The technology that has to provide it

3. The institutional environment

4. Efficient use of service


Reliable services over time for sustainability

1. Coverage

2. Continuity

3. Quantity

4. Quality

5. Cost


The user community

The user community is composed of different groups of people with

common but often also conflicting interest and ideas.

Community Management

Basic requirements for community management

1. Enabling environment which guarantees that user groups and

communities can legally establish water enterprise to manage

their water supply system.

2. A technology with operation and management requirements that

are within the capacity of the local level.

3. A level of service that responds to a realistic demand of the

community.

4. Partnership attitudes between agencies and communities or user

groups.


Basic requirements for community management

5. Transparent decision making ensuring that informed choices can

be made.

6. Impartial institution that has power of authority.

7. Adequate monitoring to enable to learn from the process.


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