[Biology Class Notes] on Waste Disposal Pdf for Exam

Municipal liquid waste is channeled through sewage systems in developed countries, where it is treated as wastewater or sewage. Before wastewater, or sewage, may enter groundwater aquifers or surface waters like rivers, lakes, estuaries, and seas, this procedure eliminates most or all of the contaminants. (See wastewater treatment for further information on sewage systems and treatment.)

 

Municipal solid waste (MSW), commonly known as refuse, is non-hazardous garbage that must be collected and transferred to a processing or disposal facility. Garbage and waste are examples of refuse. Garbage consists primarily of compostable food waste and dry materials such as glass, paper, cloth, or wood. Garbage, on the other hand, is extremely putrescible and decomposable, but trash is not. Bulky goods like old refrigerators, couches, and massive tree stumps, as well as building and demolition waste (e.g., wood, drywall, bricks, concrete, and rebar a steel rod with ridges for use in reinforced concrete), all of which require special collection and processing, are considered trash. Sanitary landfills—pits or other places covered with impermeable synthetic bottom liners where garbage is segregated from the rest of the environment—are frequently used to dispose of refuse. 

 

What is Waste Disposal?

Waste disposal means removing, discarding, recycling or destroying unwanted materials called waste that is produced from agriculture, domestic usage or industrial products. Following the correct methods for waste disposal will ensure lesser pollution and hazards for the environment. Proper waste management is necessary with steps involving the proper collection of waste and scientific treatments that may contribute less to water pollution, soil pollution and air pollution.

 

Wastes can be of numerous types and much of the waste generated today is non-biodegradable waste. Globalization and industrialization have contributed to this hugely. The dumps with harmful substances in the waste can release toxic fumes and smoke. Therefore, the correct disposal for the particular kind of waste is necessary, for example burning all kinds of wastes may lead to the above problem and cause harm to bodies. Also, dumping into rivers and filling land depressions without proper administration is not encouraged. Wastes including plastics, batteries, sanitary and oil products should be properly disposed of. Doing so may result in a hazardous environment and a polluted atmosphere. 

 

Waste management is an important term associated with waste disposal and both go hand in hand for maintaining a clean environment. Thus, the waste disposal definition should also include a waste management system. The 7 R’s associated with waste management are Refuse, Repurpose, Reduce, Reuse, Rot, Recycle and Rethink. Following each of these steps in the process of waste disposal will help enormously to live hygienically and healthily. It is necessary not only for us but also for the next generations to come. It also prevents waste disposal workers, employees in landfill facilities, and other related workmen to reduce risks associated with improper handling of wastes. It may cause blood infections, respiratory and growth problems, skin irritations, etc. Therefore, waste disposal should not be dependent upon the workers, rather the concern should start from every home. Waste segregation should be followed everywhere including homes and commercial. Segregating biodegradable waste, non-biodegradable and toxic products should be followed. 

 

Let’s learn about the various methods of waste disposal which are carried out for the cleaning up process. 

 

Methods of Waste Disposal 

The various methods of waste disposal known are as follows:

1. Landfill

2. Incineration

3. Biogas Generation

4. Composting

5. Waste compaction

6. Vermicomposting

 

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1. Landfill 

In this process, the waste type involves non-reusable and non-recyclable substances which are spread in a thin layer in specific low-lying lands or areas. These areas are dug deep where waste is disposed inside then a layer of soil will be used to cover it back. These areas are declared unfit for activities like construction of buildings for the next 20 years. That site can be made use for building parks or playgrounds in the near future. It is one of the hugely adopted methods of waste disposal in a bulk manner.

 

2. Incineration

Incineration is the treatment of waste or waste disposal by the means of burning where the garbage turns into the incombustible matter like gases and ashes. Incinerators are believed to be environmentally very dangerous as the resultants are heavy metals, which are placed in landfills ultimately making air, water, and soil polluted. However, there are numerous benefits associated with this process including decreased waste quantity, production of power and heat, pollution reduction, no transportation of waste required, control over noise and odor, and elimination of chemical and harmful germs.

 

3. Generation of Biogas

Food items, animal waste, municipal waste, vegetable/fruit peels and organic industrial wastes are biodegradable waste which means these can be decomposed by bacteria or other organisms. Using these wastes, biogas is produced at small as well as a large scale where bacteria, fungi, and other microbes easily degrade the substances. The organic biodegradable matter that is broken down or has to be decomposed serves as food for microorganisms. The biogas production process can happen anaerobically i.e. without oxygen as well as aerobically i.e. with oxygen. The outcome is biogas which is used as a fuel and the remains are used as manure in fields or plantations. Biogas is a mixture of gases, primarily methane and carbon dioxide. This kind of waste disposal method is beneficial as the wastes are utilized in production of something useful.

 

4. Waste Compaction

Waste compaction involves a proper technique that includes shredding the waste into smaller pieces, pushing to mix properly and placing it in such a way to fill voids. Waste compaction results in reducing the amount and size of waste that ultimately results in less pollution of the environment. Recycling is also one of the best methods to reduce waste and it can be performed for cans, plastic bottles, cardboards, paper, metal, textiles, electronics, batteries, tires, etc. Reusing these kinds of wastes is possible through recycling. 

 

5. Composting

Composting is one of the waste disposal methods that begin from our kitchen. It deals with all organic materials including food scraps, garden waste, fruits and vegetable peels. When these substances are buried and left under the soil for some days, those decay under the action of bacteria, fungi and other microorganisms. As a result, decomposition takes place and a humus-like substance called compost is formed. It is highly beneficial to be used as manure or fertilizer as it is nutrient-rich that can replenish the soil to grow crops or plants. It’s also known to enhance the water retention capacity of the soil and is the best alternative to harmful chemical fertilizers.

 

6. Vermicomposting

Also known as vermiculture, vermicomposting is one of the waste disposal methods and it is performed by the decomposition process using white worms, red wigglers, earthworms and other worms to break the organic matter like vegetable or food waste. Vermicast is the end product generated as a result of breakdown of organic waste by earthworms. Vermicompost or vermicast is highly water-soluble that acts as an excellent source of nutrients and thus used as fertilizer. It is often mixed with soil in a standard ratio or added as a liquid fertilizer.

 

While driving along a highway, we notice heaps of garbage on the side of the road. In India, open dumping is the most popular trash disposal method.

 

The waste heaps are frequently exposed to the elements and the environment. They rarely have a scant covering, which attracts pests and vermin.

 

These landfills are occasionally subjected to open burning, which can emit harmful gases and smoke. There have also been cases where there has been enough heat created to cause spontaneous combustion.

 

Waste is occasionally dumped illegally into rivers and canals or used to fill land depressions without sufficient consultation. In the long run, these methods cause a slew of issues. These can include everything from soil degradation to harmful chemicals leaking into subsurface water sources. As a result, correct waste disposal measures should be used to avoid such instances.