JAIN UNIVERSITY

DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING

ENVIRONMENTAL ENGINEERING & SUSTAINABILITY

QUESTION BANK WITH ANSWERS FOR MODULE -03 & 05

QUESTIONS FOR 2 Marks

State the differences between Distillation & Demineralization

In distillation, the water is boiled & then the vapour is cooled. When the vapour has condensed,
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demineralized water is produced. In case of Demineralization, the water runs through a bed of ion
exchange resin, which separates out the ionic impurities, including dissolved carbon dioxide.
What is E-Waste? List the components of E-Waste management system.
E-Waste is a generic term used to describe all types of old, end of life or discarded electrical & electronic
2 equipment such as house hold appliances, office information & communication equipments,
entertainment & consumer electronic equipment, lighting equipment, other electric & electronic tools.
Collection, Treatment & Disposal system are the critical elements of E-waste management system.
Define the terms Reverse Osmosis & Osmotic Pressure.
Reverse osmosis – it is a water purification process that removes ions, unwanted molecules & unwanted
particles from drinking water using a partially permeable membrane. As a result, the solute is kept on
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the membrane’s pressurised side & the pure solvent is allowed to pass to the other side.
Osmotic pressure – it is defined as the minimum pressure applied to a solution to prevent the inward
flow of its pure solvent across a semipermeable membrane.
List your responsibilities to reduce waste generation.
Reduce – Try to reduce the waste by buying products with minimal packaging
Reuse – Reusing items such as bags & containers.
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Recycle – Recycling materials such as plastics, papers & glass.
Composting – Setting up a compost bin or pile to dispose off organic waste such as foods, scraps &
yard trimmings etc.
Name any 4 best electronic water purifiers available in the market.
Kent guard RO water purifier
5 AO Smith Z5 water purifier
Aqua guard aura water purifier
Liv pure Glo star water purifier
What are the uses of Activated carbon in water purification.
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Following are the uses of Activated carbon in water purification:
 • Remove contamination
• Makes water odour & tasteless
• Control disinfectant byproducts
• Chlorine & organic removal
State the advantages & disadvantages of Solar powered water filtration system
Advantages:
• It is more compact and more affordable with less infrastructure maintenance costs.
• When power conditions are exceptionally low, the Solar Pure system comes with a backup
rechargeable battery, so there is never an interruption in water production.
7 • It can produce up to 20,000 liters per 12-hour day using any power supply (solar, wind, battery,
generator, etc.
Disadvantages:
• The system is not fully automated, so it will take some trained operators to diagnose issues that
occur.
• The filtered water rate amounts vary on available power input.

QUESTIONS FOR 5 Marks

Explain the Working Principle of Reverse Osmosis. List the advantages.

Osmotic pressure is the minimum pressure required to stop solvent flow through the semipermeable
membrane. Therefore, when the solution side (the side where the solute concentration is high) is
subjected to a pressure greater than the osmotic pressure, the solvent particles on the solution side move
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through the semipermeable membrane to the region where the solute concentration is low. Such inverse
solvent movement through the semipermeable membrane is called reverse osmosis.
It is important to note that the pressure applied to the solution side must be higher than the osmotic
pressure for the reverse osmosis process to proceed. Osmotic pressure is a colligative property, which
depends on the concentration of the solution. Following are the advantages of Reverse Osmosis:
• Bacteria, viruses, and pyrogen materials are rejected by the intact membrane. In this respect,
RO water approaches distilled water in quality.
• Available units are relatively compact and require little space. They are well suited to home
dialysis.
 • In average use, the membrane has a life of a little more than one to two years before replacement
is necessary.
• Periodic complete sterilization of the RO system with formalin or other sterilant is practical.

With a neat Sketch, Explain ION Exchange process for water Purification
For the ion exchange process to occur, the equipment must contain a micro-porous exchange resin. This
resin is saturated with a solution that is very loosely held. When the process is being used for water
softening purposes, sulfonated polystyrene beds are placed within the unit. These beds are saturated
with a sodium solution that covers the surface of the bed. When water is passed through the resin bed,
the ions will attach directly to the beads, which releases the solution into the sample water. Over time,
the beds will become saturated with contaminants, which is when the exchange resin will need to be
recharged or regenerated. To complete the regeneration process, it’s important that a salt brine solution
is used to flush the exchange resin. The salt brine solution consists of sodium ions. These ions will
replace the contaminants that coat the resin bed, after which the contaminants will be flushed out with
all the wastewater. Because of how the ion exchange process works, it can be used to soften hard water
that contains high levels of magnesium and calcium while also being used for the water treatment
2 process.

Explain the steps involved in Solar Powered water filtration system.

• Pre-Filtration – Water is first screened through a stainless-steel screen
• Ultrafiltration – Water then passes through additional filters to remove all bacteria, viruses, and
other causes of waterborne illnesses
3 • Activated Carbon – Reduces foul tastes and odors from water without using reverse osmosis
• Polishing Filter – Removes any carbon particles from the carbon filter from the previous step,
acts as a final safety check before ready to bottle for consumption
• Chloramine – Injects a mixture of chlorine and ammonia to preserve the water, but avoids giving
it a chlorine taste.
 Articulate the responsibilities of SPCB’s in India.
• To prepare a comprehensive program to prevent, control, and reduce water and air pollution in
the State.
• To advise the respective state Government on the subject matter regarding prevention, control,
or reduction of water and air pollution.
• To formulate, modify, or set aside effluent standards for sewage and trade effluents and for the
quality of receiving waters and classify waters of the State.
• To develop economical as well as reliable methods for treatment of sewage and trade effluents,
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for their utilization in agriculture, and their disposal on land.
• To formulate, in consultation with and having regard to the standards set by the CPCB, norms
for emission of air pollutants into the open air from different sources except for ships and
aircraft.
• To gather and pass on the information relating to water and air pollution and the prevention,
control, or reduction thereof.
• To motivate, direct, and participate in investigations and research on water pollution problems.
• To inspect sewage or trade effluents, works, and plants to treat sewage and trade effluents.
List the applications of Distillation.
• Distillation plays an important role in many water purification techniques. Many desalination
plants incorporate this method to obtain drinking water from seawater.
• Distilled water has numerous applications, such as in lead-acid batteries and low-volume
humidifiers.
• Many fermented products such as alcoholic beverages are purified with the help of this method.
5 • Many perfumes and food flavorings are obtained from herbs and plants via distillation.
• Oil stabilization is an important type of distillation that reduces the vapor pressure of the crude
oil, enabling safe storage and transportation.
• Air can be separated into nitrogen, oxygen, and argon by employing the process of cryogenic
distillation.
• Distillation is also employed on an industrial scale to purify the liquid products obtained from
chemical synthesis.
List the Objectives of Water (Prevention & control of pollution) Act 1981.
• To prevent and control water pollution
• To assess pollution levels and punish polluters
6 • To maintain or restore the wholesomeness of water
• To establish Central and State boards to carry out the objectives of the Act.
• To confer on and assign to the boards, the power, and functions relating prevention and control
of water pollution.
 • To establish Central and State water testing laboratories to enable the Boards to discharge their
functions.
• To penalize contravention of the provisions of the Act.
• To deal with matters connected with the prevention and control of water pollution.
Write a short note on THE AIR (PREVENTION AND CONTROL OF POLLUTION) ACT, 1981
• This Act was passed for the "prevention, control and abatement of air pollution."
• This law defined an air pollutant as "any solid, liquid or gaseous substance present in the
atmosphere in such concentration as may be or tend to be injurious to human beings or other
living creatures or plants or property or environment."
• In this Act, power to declare air pollution, control areas has been given to the state government
after consulting the State Board. By this, it may control or even prohibit burning of certain
materials in those specific areas.
• This Act requires approval prior to operating any industrial plant.
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• Government may suggest "control equipment" prior to giving its consent to any industry for its
operation.
• It may include chimney etc. In case there is any new technology for emission control, then the
Board may insist on this to being installed. Standards specific to industries have been specified.
• Penalties were for a minimum of six months imprisonment to a maximum of seven years and
fine up to Rs. 5,000 for every day during which contravention continues after conviction for the
first such contravention.
• This law makes it clear that when offenses are committed by a company, its director, manager,
secretary, or other officers could be held guilty and punished accordingly.

QUESTIONS FOR 10 Marks

Explain Water Purification by UV radiations. Describe the points to be considered for the
maintenance of UV water treatment system
An ultraviolet (UV) water purifier exposes living organisms, such as bacteria, viruses, or cysts to a
germicidal ultraviolet wavelength. With enough energy, UV radiation of about 254-nm wavelength
disrupts the DNA in pathogenic microorganisms so they cannot reproduce. The ultraviolet light prevents
1 bacteria from spreading disease through drinking water.
The glass quartz sleeve present in the UV water Purifier holds the UV lamp that emits a germicidal
wavelength of radiation to deactivate living organisms. The quartz glass sleeve is transparent to the UV
wavelength, which allows UV light to penetrate the glass and disinfect the water. A quartz sleeve
protects the UV lamp from the water because water and electricity do not mix well. One or two O-rings
seal the whole system together.
Maintenance of UV Water treatment System
• UV water purifiers last many years, but they require maintenance like any other water treatment
system. However, UV systems are easy to maintain and designed to run continually.
• Replace the UV lamp once a year. UV lamps use mercury vapor as fuel to ignite the UV
wavelength. Over time, the mercury inside the lamp dissipates. A UV lamp lasts about 9,000
hours or 375 days (if you run it all the time).
• Clean the quartz sleeve. The glass quartz sleeve that surrounds the lamp needs to be clean for
the UV lamp to work effectively. Check the quartz sleeve when you change the lamp to make
sure it is clean.
• Replace the quartz sleeve once every two years. Quartz sleeves are very fragile, so keeping an
extra on hand is recommended in case of an accident
 Explain the challenges of E-Waste management in India.

Explain the Practices for efficient E-Waste management.

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 Write a short note on Plastic waste management rules 2016 Water (Prevention & control of
pollution) act 1981
PLASTIC WASTE MANAGEMENT RULES
• Increase minimum thickness of plastic carry bags from 40 to 50 microns and stipulate minimum
thickness of 50 micron for plastic sheets also to facilitate collection and recycle of plastic waste
• Expand the jurisdiction of applicability from the municipal area to rural areas, because plastic
has reached rural areas also
• To bring in the responsibilities of producers and generators, both in plastic waste management
system and to introduce collect back system of plastic waste by the producers/brand owners, as
per extended producers’ responsibility
• To introduce collection of plastic waste management fee through pre-registration of the
producers, importers of plastic carry bags/multilayered packaging and vendors selling the same
for establishing the waste management system
• To promote use of plastic waste for road construction as per Indian Road Congress guidelines
or energy recovery, or waste to oil etc. for gainful utilization of waste and also address the waste
disposal issue; to entrust more responsibility on waste generators, namely payment of user
charge as prescribed by local authority, collection and handing over of waste by the institutional
generator, event organizers.
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• An eco-friendly product, which is a complete substitute of the plastic in all uses, has not been
found till date. In the absence of a suitable alternative, it is impractical and undesirable to impose
a blanket ban on the use of plastic all over the country. The real challenge is to improve plastic
waste management systems.
WATER (PREVENTION & CONTROL OF POLLUTION) ACT 1981
It is an Act to provide for the prevention and control of water pollution and the maintaining or restoring
of wholesomeness of water for the establishment, with a view to carrying out the purposes aforesaid, of
Boards for the prevention and control of water pollution, for conferring on and assigning to such Boards
powers and functions relating thereto and for matters connected therewith. This Act came into force on
23 March 1974 and was amended in the years 1978 and 1988. There are a total of 8 chapters and 64
Sections in the Act.
• The purpose of this act is to provide for the prevention and control of water pollution and the
maintenance or restoring wholesomeness of water for the establishment, with a view to carrying
out the purpose of aforesaid of Boards for the prevention and control of water pollution, for
conferring on and assigning to such Boards powers and functions relating thereto and for matters
connected there with.
• This is the Act that established the Central and a State Board and also the authority and power
to constitute as many committees as it feels essential to carry out specific functions for it.
• The Act specifically prohibits "any poisonous, noxious or polluting matter' into any stream or
well.
• A consent from the State Board is required for any type of new discharge into any new stream
or well.
• This also includes consent for "temperature" discharges as done by cooling tower users.
• In general, this means that a state consent or permit is required for all types of intakes and/or
discharge of any type of liquid or water either from a running stream or well.
• Under these rules, "effluent standards to be complied with by persons while causing discharge
of sewage or silage or both" have been specified. Standards for small scale industries have been
specified separately.
• Penalties for non-compliance with the permit or polluting in any way are imprisonment for three
months and fine of Rs. 10,000 or fine up to Rs. 5,000 per day of violation or both plus any
expenses incurred by the Board for sampling, analysis, inspection etc.
• These penalties can also be imposed for "obstructing any person acting under the orders or
direction of the Board" or for "damages to any work or property of the Board."
 JAIN UNIVERSITY
DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING
ENVIRONMENTAL ENGINEERING & SUSTAINABILITY
QUESTION BANK WITH ANSWERS FOR MODULE -01, 02 & 04

PART -A (2 MARKS)
Why the energy resources are categorized as renewable & non-renewable energy resources?
Resources which cannot be exhausted even after continuous utilization are termed as renewable energy resources
while the resources which cannot be immediately replaced once they are depleted are termed as non-renewable

1 energy resources. The major reason for the energy resources being categorized as renewable or non-renewable
resources is Sunlight, wind, air etc are the renewable energy sources that are constantly being replenished,
plentiful & all around us. Fossil fuels like coal, oil & gas – on the other hand are non-renewable resources that
take hundreds or millions of years to form.
How do solar chargers offer advantage in terms of energy usage?
solar chargers are a device that employs solar energy to supply electricity to the devices or batteries. They are
automatic, portable chargers for your phones and laptops. They check whether the device needs charging. When
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the battery of the device is low, the charger starts charging the device. After a complete charge, the charger will
automatically shut off and thus reduce power consumption. The average energy saved by solar chargers is around
80 percent.
What are the essential components of a Micro hydel plant?
A typical micro hydel power plant consists of these basic components.
• Water conveyance – channel, pipeline or pressurized pipelines called penstocks that delivers the water

3 • Turbine, pump, or waterwheel – transforms the energy of flowing water into rotational energy.
• Alternator or generator – transforms the rotational energy into electricity
• Regulator – controls the generator.
• Wiring – delivers the electricity.
What are green materials? give few examples of the same
Materials are classified as green materials solely based on how they intrinsically affect the environment.

4 Materials that are made with non-toxic chemicals, recyclable in nature and are produced through environmentally
friendly processes are called as green materials. The commonly used green materials in the field of electronics
include aluminium, borosilicate glass, iron alloys, graphene & biomaterials like silk etc…
What is Waste Incineration? what is the need of waste incineration.

5 Waste incineration is the process of using relatively high temperatures to combust waste and reduce its volume
by 95% and mass by 80-85%. Following are the necessities of waste incineration.
 • Incineration can destroy a wide range of highly contaminated wastes & greatly reduce the amount of
material that must be disposed off in a land fill.
• Energy may be recovered from incineration through many ways like gas to water heat exchange.
Outline the steps involved in hydro-metallurgical processing.
Hydrometallurgy is a technique within the field of extractive metallurgy, the obtaining of metals from their ores.
It involves the use of aqueous solutions for the recovery of metals from ores, concentrates & recycled or residual

6 materials. Following are the steps involved in hydro-metallurgical processing

• Leaching
• Solution concentration & purification – by Precipitation or froth flotation
• Metal recovery – by electrolysis, gas reduction etc.
List the necessities of E-waste recycling?
Following are the necessities of e-waste recycling
• It prevents toxic hazards
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• It allows us to reuse materials
• It takes care of the environment
• Rich Source of Raw Materials
What are the components of E-waste?
• Computer peripherals: monitor, keyboard, mouse, circuit boards, CDs, floppies, laptops, servers, etc.
• Telecommunication devices: phones, cell phones, pagers, fax machine, routers, transmitters, Radio

8 Frequency (RF) equipment, etc.

• Industrial electronics: sensors, automobile electronic devices, medical devices, etc.
• Lighting devices: fluorescent tubes Household appliances: TV, fridge, washing machine, video, camera,
etc
PART -B (5 MARKS)
Explain the advantages of renewable energy.

Following are the advantages of Renewable Energy:

• Renewable Energy Sources Will Not Run Out: As it comes from the name, a renewable energy source is
sustainable, meaning that it will not run out soon. For example, the sun is expected to shine every morning for
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at least 4.5 - 5.5 billion years to come, so we can consider it a renewable source of energy. This might be the
most important difference between renewables and fossil fuels.
• Renewable Energy Is Reliable: Despite fossil fuels that are always subject to disputes and wars between
countries, we can easily and peacefully gain control of renewable energy sources. In other words, trade laws,
political instabilities, territorial claims, and markets' turmoil cannot impact the use of renewable energy sources.
 Although renewable energy sources are not distributed equally, with a smart and widespread energy network, it's
possible to use them as reliable means of supplying energy.
• Renewable Energy Is Environmentally Friendly: Renewable energy sources are natural ways of energy
generation, and therefore, can be considered clean. Although renewable energy technologies can cause some
emissions, overall, minimum carbon and GHG will be emitted to the environment when using them. When you
compare them with fossil fuels, the difference is significant. Therefore, catastrophic environmental issues like
global warming, climate change, and low air quality can be omitted if we go for renewable energy.
• Renewable Energy Can Increase Public Health: By reducing greenhouse emissions and other polluting
substances, we will have healthier air and soil. This will improve public health, and subsequently, people we will
have happier lives. Additionally, having a healthier population will cause a significant reduction in the health
budget people and governments should set aside each year. Scientists have tried to improve fossil fuel
technologies to make them less polluting without reducing the efficiency. However, renewable energy
technologies are still way healthier than traditional technologies.
• Renewable Technologies Create Lots of Jobs: Apart from the environmental impact of using renewable
technologies, they can have some beneficial influence on the economy. This is especially important in some
unprivileged regions. In fact, this is a new and stable job market that has recently emerged and can empower
people in poor areas. With a concerted effort and prudent investment, renewable jobs can reduce poverty all over
the globe. Also, it can prevent people from emigrating from the countryside to urban areas. Governments can
offer them a fair share for generating renewable electricity in their farms. In advanced countries such as the UK,
numerous renewable jobs have already been created in the wake of governmental grants.
• Renewable Technologies Require Less Maintenance Cost: If you look at renewable energy technologies
and compare them with fossil fuels' power stations, you see less moving or combusting parts. Although you can
see turbines in wind farms or hydropower stations, solar energy systems don’t need any rotating parts. This
makes renewable energy technologies more durable, and therefore, you will spend less money on maintenance
and repair. Overall, the operational cost of renewable energy stations is significantly less than what we see in
traditional power stations.
• Renewable Energy Can Reduce Turmoil in Energy Prices: If you usually follow the news, you must have
heard of daily ups and downs in the oil prices. Renewable energy can be of great help in this regard and reduce
this turmoil and make the global energy market more stable. Because using renewable energy only demands an
initial investment, and you do not need any fuels.
State the working principle of a windmill and list the factors to be considered for site selection of a wind
mill.

Working principle:
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A wind turbine turns wind energy into electricity using the aerodynamic force from the rotor blades, which work
like an airplane wing or helicopter rotor blade. When wind flows across the blade, the air pressure on one side
of the blade decreases. The difference in air pressure across the two sides of the blade creates both lift and drag.
 The force of the lift is stronger than the drag and this causes the rotor to spin. The rotor connects to the generator,
either directly or through a shaft and a series of gears (a gearbox) that speed up the rotation and allow for a
physically smaller generator. This translation of aerodynamic force to rotation of a generator creates electricity.

Site selection for a windfarm: There are a few key technical and environmental factors that influence the
feasibility of a wind farm. The key technical requirements are:
• Adequate wind speed
• sufficient area
• appropriate ground conditions
• low population density
• minimum risk of agro-forestry operations
• close to suitable electricity grid
• feasibility of access for abnormal loads
• suitable terrain and topography
• privately owned free hold land/supportive land holders
• good industrial support for construction and ongoing operations.
Write a note on Hydrogen fuel cell & explain the technical challenges involved in the storage of hydrogen.
A fuel cell is a device that generates electricity through an electrochemical reaction, not combustion. In a fuel
cell, hydrogen and oxygen are combined to generate electricity, heat, and water. A fuel cell is composed of an
anode, cathode, and an electrolyte membrane. A typical fuel cell works by passing hydrogen through the anode
of a fuel cell and oxygen through the cathode. At the anode site, a catalyst splits the hydrogen molecules into
electrons and protons. The protons pass through the porous electrolyte membrane, while the electrons are forced
through a circuit, generating an electric current and excess heat. At the cathode, the protons, electrons, and
oxygen combine to produce water molecules. As there are no moving parts, fuel cells operate silently and with
extremely high reliability.
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 Technical challenges associated with storage of hydrogen: Hydrogen is difficult to store due to its low
volumetric energy density. It is the lightest of and simplest of all elements, being lighter than helium, and so is
easily lost into the atmosphere. In enclosed locations with normal temperatures, spilled liquid hydrogen will
create enormous gas pressures, tearing apart vessels without safety valves. The two prime dangers from fuel cell
and hydrogen-powered vehicles are the danger of electrical shock and the flammability of the fuel. Storage of
hydrogen as a gas typically requires high pressure tanks (5,000–10,000 tank pressure). Storage of hydrogen as a
liquid requires cryogenic temperatures because the boiling point of hydrogen at one atmosphere pressure is
−252.8°C
Explain the characteristics of eco-friendly laptops.
Following are the characteristics of eco-friendly laptops
• International Ecolabels: The easiest way to distinguish whether a laptop is eco-friendly or not is to look
for international ecolabels. If you’re shopping in store, these can come in the form of stickers on the
computer chassis or badges in the product brochures, promotional flyers, and other marketing materials.
If you’re shopping online, information about such labels can be found on product sites.
• Sustainable Materials: Components are made of post-consumer recycled plastic or sometimes even
recycled ocean-bound plastic, and many also integrate post-industrial recycled metal. Parts made of such

4 materials may include keyboard keycaps, speakers, peripherals, adapters etc.

• Energy Efficiency: The more energy-efficient a laptop is the less electricity it consumes, and thus the
smaller environmental impact it has.
• Better Quality Often Means Longer Lifespan: Buy a laptop that’s a little more powerful than you
need at the moment. Crucial components like the CPU and GPU are usually permanent in a laptop and
cannot be upgraded like in a desktop. Extra laptop performance can be a bonus, making you ready for
ever-more-hungry software of the future.
• Recyclability: One additional thing to keep in mind is whether the manufacturer you are buying from
can help you recycle your laptop when you swap it for a new one.
Explain the various environmental & health hazard due to improper disposal of e-waste.

Environmental impacts: Although electronics constitute an indispensable part of everyday life, their hazardous
effects on the environment cannot be overlooked or underestimated. The interface between electrical and
electronic equipment and the environment takes place during the manufacturing, reprocessing, and disposal of
these products. The emission of fumes, gases, and particulate matter into the air, the discharge of liquid waste
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into water and drainage systems, and the disposal of hazardous wastes contribute to environmental degradation.
I There are a number of specific ways in which e-waste recycling can be damaging to the environment. Burning
to recover metal from wires and cables leads to emissions of brominated and chlorinated dioxins, causing air
pollution. During the recycling process in the informal sector, toxic chemicals that have no economic value are
simply dumped. The toxic industrial effluent is poured into underground aquifers and seriously affects the local
 groundwater quality, thereby making the water unfit for human consumption or for agricultural purposes.
Atmospheric pollution is caused by dismantling activities as dust particles loaded with heavy metals and flame
retardants enter the atmosphere. These particles either redeposit (wet or dry deposition) near the emission source
or, depending on their size, can be transported over long distances. The dust can also enter the soil or water
systems and, with compounds found in wet and dry depositions, can leach into the ground and cause both soil
and water pollution. Soils become toxic when substances such as lead, mercury, cadmium, arsenic, and
polychlorinated biphenyls (PCBs) are deposited in landfills.
Health impacts: For instance, in terms of health hazards, open burning of printed wiring boards increases the
concentration of dioxins in the surrounding areas. These toxins cause an increased risk of cancer if inhaled by
workers and residents. Toxic metals and poison can also enter the bloodstream during the manual extraction and
collection of tiny quantities of precious metals, and workers are continuously exposed to poisonous chemicals
and fumes of highly concentrated acids. Recovering resalable copper by burning insulated wires causes
neurological disorders, and acute exposure to cadmium, found in semiconductors and chip resistors, can damage
the kidneys and liver and cause bone loss. Long-term exposure to lead on printed circuit boards and computer
and television screens can damage the central and peripheral nervous system and kidneys, and children are more
susceptible to these harmful effects.
Explain the steps involved in the e waste recycling process?

Step 1: Manual sorting and separation: Electronic items are manually sorted, and components that should not
be shredded or crushed are removed by hand, such as batteries, UPS battery systems, toner cartridges, and
fluorescent lights

Step 2: Shredding: An Initial Size Reduction step shreds the electronic items into small 100mm size pieces, and
a Secondary Size Reduction step further breaks down materials into even smaller fragments that are well suited
for the separation process. Any dust extracted during this process is disposed of using environmentally-friendly
methods.
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Step 3: Magnetic removal: Steel and iron fragments are removed by magnets.

Step 4: Metallic and non-metallic separation: Other metals, such as aluminium, copper, and brass are
separated from non-metallic materials, such as glass and plastic. Separation occurs through Eddy currents, optical
identification, and magnets.

Step 5: Separation by water: Plastic and glass are separated by using water. Lead containing glass may be sent
to lead smelters to be used to make new products such as batteries, new CRTs, and x-ray shields. Plastics are
separated by colour and sold to plastic recyclers. Once the raw materials have been separated, they can be sold
as commodities to recyclers and manufacturers to make new electronic devices or other items. Circuit boards are
 ground up and smelted, the gases are captured, and the metals can be sold as raw commodities. Wood from older
television model cabinets may be chipped and used to be burned as biofuel.
PART -C (10 MARKS)

1 Write a short note on the following: a) CRT recycling process b) Solar thermal Collectors

a) CRT recycling process: A cathode ray tube (CRT) is the glass video display component of an electronic
device usually a television or computer monitor. EPA encourages repair and reuse as a responsible way
to manage CRTs. If reuse or repair are not practical options, CRTs can be recycled. Recycled CRTs are
typically disassembled so that valuable materials can be recovered. Because the Cathode Ray Tubes
(CRTs) that are present in computer monitors and old televisions contain large amounts of toxins such as
lead that can be harmful to human health and to the environment, recycling these devices requires a
separate process from most other electronics.
Recycling process:
• Monitor body and cathode ray separation: The front of the monitor or television body must be removed
to access the CRT within, and the outer shell of the monitor or television must be recycled with other e-
waste.
• Size reduction: The CRT tubes and screens are shredded into tiny pieces, and the glass dust is removed
using environmentally friendly methods.
• Metal removal: Using magnets, iron and steel are removed from the broken pieces, and then Aluminum
and copper is removed by passing the rest of the material through Eddy currents.
• Washing: Any remaining glass fragments are cleaned to remove oxides, phosphors, and dust extracts,
leaving clean glass to be sorted one last time.
• Glass sorting: The leaded glass is separated from unleaded glass. Both types of glass can be used to
manufacture new screens. Lead-containing glass may also be sent to lead smelters to be used to make
new products such as batteries, new CRTs, and x-ray shields.
The best e-waste recycling systems consist of self-contained recycling processes after the initial manual
separation step, as well as self-contained collection of raw materials to be shipped to manufacturers. This
ensures the highest level of protection for both human health and the environment

b) Solar thermal collectors: These are black painted metal-either copper, aluminium, steel, or plastic
plates. In order to reduce the useful heat losses-which increase with rising temperatures-transparent
covers are placed on the collectors and the heat losses at the back of the absorber are reduced by
appropriate insulation. With these collector temperatures up to 80°C with conversion efficiency of about
50-60% can be achieved. The properties of this collector are well known and they are manufactured in
many parts of the world. Solar thermal collectors can be classified based on the heat requirement into:
 • Non-concentrating collectors fully utilize the global radiation. The simplest design of a non-
concentrating collector is the flat plate collector.
• Concentrating collectors use mainly the direct beam of the radiation by concentrating irradiation on the
absorber thus increasing the intensity of radiation on the absorber. The concentrator uses a mirror or a
lens to concentrate light. Concentrating collector systems are preferred technology in regions with more
than 2,500 annual sunshine hours to obtain fluid temperatures above 150°C. The concentrator is normally
equipped with a tracking device that follows the sun with the absorber located along the focus to extract
the maximum amount of sunlight for heating.
2 List the Properties & uses of the following: a) Aluminium b) Graphene
Properties of Aluminium:
 Light Weight: Aluminum is a very light metal with a specific weight of 2.7 g/cm3, about a third of that
of steel. This cuts the costs of manufacturing with aluminum. Again, its use in vehicles reduces dead-
weight and energy consumption while increasing load capacity. This also reduces noise and improves
comfort levels.
 Electrical and Thermal Conductivity: Aluminum is an excellent heat and electricity conductor and in
relation to its weight is almost twice as good a conductor as copper. This has made aluminum the first
choice for major power transmission lines. It is also a superb heat sink for many applications that require
heat to be drained away rapidly, such as in computer motherboards and LED lights.
 Reflectivity: Aluminum is a good reflector of visible light as well as heat, and that together with its low
weight, makes it an ideal material for reflectors in, for example, light fittings or rescue blankets. Cool
roofs made of coated aluminum are invaluable in reducing internal solar heat within a house, by reflecting
up to 95% of sunlight.
 Ductility: Aluminum is ductile and has a low melting point and density. It can be processed in several
ways in a molten condition. Its ductility allows aluminum products to be formed close to the end of the
product’s design. Whether sheets, foil, geometrical configurations, tubes, rods or wires, aluminum is up
to them all.
 Non-magnetic - Aluminum is non-magnetic, making it useful for electrical shielding's as in computer
disks, dish antennas, busbars, or magnet housings.
 Non-toxic - Aluminum is non-toxic and is used to make woks, pressure cookers and many other cooking
utensils without fear. It is easily cleaned and does not contaminate the food at any stage.
 Sound and Shock Absorption - Aluminum is an excellent sound absorber and is used for constructing
ceilings. It is also used in auto bumpers due to its shock-absorbing properties.
 Non-sparking - Aluminum produces no sparks when it comes into contact with itself or non-ferrous
metals.
 Recyclability - Aluminum is 100% recyclable and recycled aluminum is identical to the virgin product.
This makes it a much more cost-effective source material for production runs. The re-melting of
 aluminum requires little energy: only about 5% of the energy required to produce the primary metal
initially is needed in the recycling process.
 Corrosion Resistance: Aluminum naturally generates a protective thin oxide coating which keeps the
metal from making further contact with the environment.
Uses of Aluminium
 Aluminium is widely used in the packaging industry for the production of coils, cans, foils, and other
wrapping materials.
 It is also a component of many commonly used items such as utensils and watches.
 In construction industries, aluminium is employed in the manufacture of doors, windows, wires, and
roofing.
 It is used in the transport industry for the production of cycles, spacecraft, car bodies, aircraft and marine
parts.
 Many coins are made up of alloys that contain aluminium.
 Aluminium also finds applications in the production of paints, reflective surfaces, and wires.
 Smartphones, tablets, laptops, and flat screen TVs are being made with an increasing amount of
aluminum. Its appearance makes modern tech gadgets look sleek and sophisticated while being light and
durable. It is the perfect combination of form and function which is critical for consumer products. More
and more, aluminum is replacing plastic and steel components, as it is stronger and tougher than plastic
and lighter than steel. It also allows heat to dissipate quickly, keeping electronic devices from
overheating.
Properties of Graphene:
 High conductivity: Through the use of graphene, the useful life of batteries could be increased by 10,
as well as charging in less time, which translates into an autonomy improvement. It's only a matter of
time before graphene replaces a large part of the lithium batteries currently in use.
 Lightness: Graphene is also suitable for manufacturing batteries for drones, as these would be lighter
and tougher.
 Transparency and flexibility: Graphene is a transparent material and absorbs very little light. graphene
can be folded like cling film, so the chances of breakage are much lower.
 High resistance: As well as being an excellent electric conductor, graphene is a very resistant material,
so big advances in the lighting sector are expected. For example, graphene light bulbs could increase the
useful life of each globe and consume less energy than the LED lights that we currently have.
Uses of Graphene:
 Graphene in the energy sector: The use of graphene in the manufacturing of rechargeable batteries
could be a great leap towards energy efficiency. This material would prevent devices overheating, so they
would be tougher and lighter.
 Graphene in construction: The use of graphene applied to construction promises to improve the
insulation of buildings. And not just that, but they could be more resistant to corrosion, dampness, and
fire, and therefore tougher and more sustainable.
 Graphene in electronics: The characteristics of graphene could change the electronics sector
completely. With the application of this material, smaller, lighter, tougher, and more efficient
devices could be manufactured, impossible to obtain with the components that are used today.
 Graphene in health: The applications of graphene in the health and medicine sectors are also
fascinating. Since it is stronger, more flexible, and lighter, hearing aids could be developed. We could
even be speaking about making bones and muscles that would be introduced through surgical operations.
Still in the research phase, it's believed that graphene oxide could be a good ally in the diagnosis of
diseases and their subsequent treatment.