Frank Brothers Solutions for ICSE Class 9 Biology Chapter 22 Sources Of Waste

PAGE NO: 208

Answer 1: Examples of domestic waste are left over food items, faeces and urine, broken nails. (Write any two)
Domestic waste is any material discarded from our households during our daily lives. It is important to separate this waste into biodegradable and non-biodegradable categories for easy disposal.
Teacher's Tip: Think of the word "Domestic" as "Home" - anything you find in a kitchen or bathroom bin is domestic waste.
Exam Tip: If the question says "Write any two," always try to provide three examples just in case one is not accepted.

Answer 2: Waste is a product of human activity, generated from a great variety of sources.
Almost every action we take, from eating to manufacturing goods, creates some form of unwanted material. As our civilization grows and uses more resources, the amount of waste we produce increases significantly.
Teacher's Tip: Remember: No human activity = No waste. We are the primary creators of waste on Earth.
Exam Tip: Use the keyword "generated" to describe how waste is created to sound more scientific.

Answer 3: Garbage refers to refuse consisting largely of easily decomposable and putrefying organic (animal and vegetable) waste.
This type of waste comes from living things and can be broken down naturally by bacteria in the soil. Because it rots (putrefies), it is often the cause of bad smells in trash bins.
Teacher's Tip: Associate "Garbage" with "Green" - it mostly comes from plants and food items.
Exam Tip: Make sure to mention "animal and vegetable" to show you understand that garbage is biological in nature.

Answer 4: Waste paper, empty printer cartridges, boxes and packaging, scrap metal etc. (Write any two)
These items are typically found in commercial buildings and places of business. Most of this waste, especially paper and metal, is highly valuable for recycling programs.
Teacher's Tip: Visualize a school office; things like paper and empty ink boxes are the main types of waste there.
Exam Tip: "Printer cartridges" is a specific and modern example that earns high marks for accuracy.

Answer 5: The basic sources of waste are:
Kitchen
Industry
Agricultural land
Municipality
Offices
Waste is categorized based on where it comes from, such as homes, factories, or farms. Each of these different sources produces specific types of materials that require different handling methods.
Teacher's Tip: Use the acronym "K-I-A-M-O" (Kitchen, Industry, Agriculture, Municipality, Office) to memorize this list easily.
Exam Tip: Write each source on a new line using a bullet-style format even if you don't use list tags; it looks much cleaner.

Answer 6: Human waste
This specifically refers to the biological waste products like urine and faeces produced by our bodies. Managing this waste through proper sewage systems is vital for preventing the spread of infectious diseases.
Teacher's Tip: Human waste is "Bio-waste" because it is produced by a living organism.
Exam Tip: Keep this answer short and direct as it is usually a one-word or short-phrase answer.

Answer 7: Construction unit
A construction unit generates waste whenever buildings are built, renovated, or demolished. This includes heavy materials like broken bricks, cement dust, and scrap metal rods.
Teacher's Tip: Whenever you see a "Work in Progress" sign at a building site, you are looking at a construction unit.
Exam Tip: Use the exact term "Construction unit" as provided in your textbook for maximum marks.

Answer 8: Sewage is a complex mixture of many distinctive chemicals. It has high concentrations of ammonium nitrate, phosphorous and many dissolved solids.
It is essentially the wastewater that travels from our homes and factories through underground pipes. These chemicals can be very harmful to fish and plants if the sewage is dumped into rivers without being treated.
Teacher's Tip: Think of "S" for Sewage and "S" for Sink and Shower water.
Exam Tip: Mentioning specific chemicals like "ammonium nitrate" and "phosphorous" demonstrates a deep understanding of the topic.

Answer 9: Crop residues, fertilizers, insecticides, herbicides and farmyard waste.
These wastes are a result of farming and looking after livestock. While some parts are natural, the chemicals like insecticides can stay in the soil and water for a very long time.
Teacher's Tip: If it's used to grow crops or kill bugs on a farm, it's agricultural waste.
Exam Tip: Always include "crop residues" as it is the most common organic waste found on farms.

Answer 10: Sound sewage system prevents environmental pollution and requires efficient management of collection, treatment and recycling or safe disposal of sewage. It also prevents serious health hazards including viral and bacterial disease transmission.
By safely moving wastewater away from our living areas, we stop germs from contaminating our drinking supply. A well-managed system can even turn waste back into clean water through advanced recycling processes.
Teacher's Tip: A "Sound" system means a "Safe and Strong" system that protects the community.
Exam Tip: Emphasize the prevention of "disease transmission" to show why sewage management is a health priority.

Answer 11: Due to growing urbanization and development, large quantities of waste is generated due to construction work, some of which includes building materials used for insulation, broken nails, electrical wiring, switches, bulbs, wood, rubble etc. Many hazardous wastes such as lead, asbestos, paints etc. are also generated by construction units. All these lead to environmental pollution. Also there is the problem of disposing off these wastes safely without harming the environment.
As cities get bigger and more buildings are made, the amount of debris created becomes a major environmental challenge. Some of these materials are toxic and cannot simply be thrown in a regular landfill without causing soil damage.
Teacher's Tip: Urbanization = City Building = More Construction Waste.
Exam Tip: Identify "urbanization" as the main cause of increased construction waste in your explanation.

Answer 12: E-waste or electronic waste refers to loosely discarded, surplus, obsolete, or broken electronic or electrical devices.
This includes everything from old mobile phones to broken television sets and computer parts. E-waste is special because it often contains valuable metals like gold as well as toxic substances like mercury.
Teacher's Tip: If it used a battery or a plug and it is now in the trash, it is E-waste.
Exam Tip: Use words like "obsolete" (out of date) to accurately describe what makes a device waste.

Answer 13: Discarded computers and broken cell phones
These are modern examples of technology that people replace very frequently. They are dangerous if thrown into regular bins because their internal batteries can leak chemicals into the ground.
Teacher's Tip: Think of gadgets! Your old tablet or broken game console are prime examples.
Exam Tip: Providing specific examples like "cell phones" makes your answer much stronger.

Answer 14: Used paper and old furniture
These are common non-electronic office or household items that are discarded during cleaning or renovations. While paper is easily recycled, wooden furniture is often considered bulky waste.
Teacher's Tip: Think of "Tree Products" - both paper and wood furniture come from trees and are common waste types.
Exam Tip: These are the best examples to use when asked for simple, non-hazardous waste.

Answer 15: Mining waste includes waste generated during the extraction, beneficiation and processing of minerals. This comprises slimes, gangue, tailing piles and leach residues.
Hazards posed by mining include:
(a) Release of harmful gases such as methane.
(b) Elimination of existing vegetation and destruction of the genetic profile of soil.
(c) Continuous mining at a place can displace or destroy wildlife and habitat.
Mining creates huge amounts of waste because for every tiny bit of metal found, tons of rock must be dug up. This process can ruin local ecosystems by removing plants and forcing animals to find new homes.
Teacher's Tip: Remember the three "H's" of mining hazards: Habitats, Health (gases), and Hectares of plants lost.
Exam Tip: Learn technical terms like "gangue" and "slimes" to score top marks in the science section.

Answer 16 Waste that is produced by any industrial activity such as that from factories, mills and mines is called industrial waste.
Factories create massive amounts of scrap materials and chemical runoff while making the products we use every day. This waste is often more concentrated and dangerous than the waste we produce at home.
Teacher's Tip: Just think of a big smoking factory chimney; the waste coming out of that factory is industrial waste.
Exam Tip: Always include "factories" and "mills" in your definition to clearly identify the source.

Answer 17: (i) (d)Non-biodegradable chemicals
(ii) (a) Eutrophication
(iii) (a) reducing discharge of waste
(iv) (b) biodegradable pollution
(v) (b) secondary treatment
(vi) (c) sewage
(vii) (b) CO
(viii) (c) reduction in oxygen
(ix) (a) increase
(x) (c) Biological Oxygen Demand
These terms describe the scientific ways we measure and talk about water pollution and its effects on nature. For instance, Eutrophication is what happens when too many nutrients make algae grow too fast in a lake.
Teacher's Tip: Remember "B.O.D." stands for "Biological Oxygen Demand" - it's like measuring how "breathless" the water is.
Exam Tip: For multiple-choice questions, write the correct letter and the full answer text together to avoid any confusion.