Solid Waste Management MCQ Quiz - Objective Question with Answer for Solid Waste Management - Download Free PDF

Explanation:

Conservancy system

• Definition: In the conservancy system, waste is collected from individual households using buckets or carts, and then transported to a central disposal or treatment location.

• Usage: This system was common in older or less-developed areas before the development of more advanced water-based sewer systems. It is labor-intensive and often used in areas where water carriage systems are not feasible.

 Additional Information

1. Hygienic system

   • This term is more general and refers to a system that ensures proper sanitation, but it doesn't specifically refer to waste collection via buckets or carts.

2. Water carriage system

   • This is a more modern system in which waste is carried by water through pipes to a central treatment facility. It is commonly used in most urban areas today.

3. Bucket system

   • While the bucket system involves the use of buckets to carry waste, the correct term for this method is the conservancy system, not just the "bucket system." The bucket system is a component of the broader conservancy system.

The correct answer is Replace.

Key Points

• The 3R principle in waste management stands for Reduce, Reuse, and Recycle.
• These principles aim to minimize waste and encourage sustainable practices.
• Reduce means to cut down on the amount of waste we produce.
• Reuse involves finding new ways to use items that might otherwise be thrown away.
• Recycle means turning waste materials into new products to prevent waste and reduce consumption of new resources.
• Replace is not part of the 3R principle; it suggests substituting one item for another, which does not necessarily contribute to waste reduction.

Additional Information

• By following the 3R principle, individuals and organizations can significantly reduce their environmental impact.
• Practicing the 3Rs helps conserve natural resources, reduce pollution, and save energy.
• Many communities have programs and initiatives to support the 3R principle, including recycling centers and educational campaigns.
• Understanding and implementing the 3Rs can lead to more sustainable living and a healthier planet.

The correct answer is 2) 1 and 2 only.

Key Points

• Gasification is a process that converts organic or fossil fuel-based carbonaceous materials into carbon monoxide, hydrogen, and carbon dioxide.
• It takes place in a low-oxygen environment where the amount of oxygen is not enough to support complete combustion.
• Gasification produces syngas (synthesis gas), which is a fuel-rich product consisting mainly of carbon monoxide and hydrogen.

Additional Information

• While gasification does reduce the emission of some toxic gases compared to direct combustion, it does not completely eliminate them. Therefore, the statement that it does not emit any toxic gases is incorrect.
• Gasification is a thermochemical process, not a biological one, which means the statement that it is a purely biological process is incorrect.
• Syngas produced through gasification can be used for various applications, including electricity generation, chemical production, and as a fuel for internal combustion engines.

The correct answer is Decomposing organic waste using earthworms.

Key Points

• Vermiculture is the cultivation of earthworms to decompose organic waste material.
• In the process, earthworms consume organic waste and convert it into nutrient-rich compost known as vermicompost.
• This method is highly efficient for waste management because it accelerates the decomposition process and reduces the volume of organic waste.
• Vermiculture helps in recycling organic waste into a valuable product that can improve soil health and fertility.
• It is an eco-friendly and sustainable approach to waste management that minimizes the reliance on chemical fertilizers.

Additional Information

• Vermiculture can be practiced on a small scale in households or on a large scale in commercial operations.
• Earthworms used in vermiculture include species such as Eisenia fetida (red wigglers) and Lumbricus rubellus.
• The vermicompost produced is rich in essential nutrients such as nitrogen, phosphorus, and potassium, which are beneficial for plant growth.
• Vermiculture also helps in reducing greenhouse gas emissions by diverting organic waste from landfills.

Concept:

Municipal solid waste:

• Municipal solid waste (MSW) is more commonly known as trash or garbage
• It consists of everyday items we use and then throw away, such as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, paint, and batteries.
• It is the non-hazardous solid waste
• It comes from our homes, schools, hospitals, and local councils

The major constituents of Municipal solid waste:

Explanation:

Solid wastes can be categorized in the following 3 categories:

1. Municipal wastes: These include food wastes, rubbish, ashes and residues, demolition and construction waste, treatment plant waste and some special wastes.
2. Industrial wastes: Wastes arising from industrial activities and it typically includes rubbish, ashes, demolition and construction wastes, hazardous wastes and some special wastes.
3. Hazardous wastes: Wastes that pose a substantial danger immediately or over a period of time to human, plant or animal life. They can be radioactive substance, chemicals, biological wastes, flammable wastes and explosives.

As per CPCB (Central Pollution Control Board)

Solid waste generated in small cities …………… 0.1 kg per capita per day

Solid waste generated in medium cities ………… 0.3-0.4 kg per capita per day

Solid waste generated in large cities …………… 0.5 kg per capita per day

Explanation:

Chemical conditioning is used for pretreatment purposes such as coagulation, disinfectant, pH control, etc.

Sludge thickening is a process in which the total volume of liquid decreases as the solid concentration increases but the sludge will behave like a liquid.

Elutriation is an unit operation in which a solid or solid liquid mixture is intimately mixed with a liquid for the purpose of transferring certain components to the liquid.

Dewatering of sludge is the process of removal of water in sludge by filtration or by solar radiation process.

Explanation:

Sludge bulking:

(i) A Sludge that exhibits poor settling characteristics is called a bulking sludge. Filamentous micro-organisms (e.g. fungi) have been found to be responsible for a bulked sludge. Filamentous micro-organisms are observed due to low nutrient content, high sludge age, and low F/M ratio.

(ii) The most successful methods to control these organisms, as per latest research, are:

(a) Reduction of the sludge age to less than 6 days

(b) Chlorination of return activated sludge

(c) Addition of nutrient if it is less (BOD₅ : N₂ : P ratio recommends = 100 : 5 : 1)

Screens are used to stop the flow of larger particles like paper, feces, garbage, leaves, etc.

These are removed by raking and disposal is done by incineration as it may produce high calorific value.

Flocculation: It is the process by which fine particulates are caused to clump together into a floc. The floc may then float to the top of the liquid and settle to the bottom of the liquid (sedimentation).

Waste utilization:

• Disposal of solid wastes is a stinging and widespread problem in both urban and rural areas in many developed and developing countries.
• Municipal Solids must be municipal solid waste (MSW) collection and disposal is one of the major problems of the urban environment in most countries worldwide today.
• MSW management solutions must be financially sustainable, technically feasible, socially, legally acceptable, and environmentally friendly.
• Solid waste management issue is the biggest challenge to the authorities of both small and large cities.

Waste utilization is achieved by Reuse, Reclamation, and Recycling of waste material.

There are mainly two methods (Indore and Bangalore method) adopted in India for decomposition of Solid wastes generated. The main difference between Indore Method and Bangalore Method for decomposition of MSW is given below:

Concept:

Bangalore method

It is an anaerobic method conventionally carried out in pits. 

In the Bangalore method of composting, dry waste material of 25 cm thick is spread in a pit and a thick suspension of cow dung in water is sprinkled over for moistening.

Indore method

It is an aerobic method. 

The Indore method of composting in pits involves filling of alternate layers of similar thickness as in the Bangalore method.

However, to ensure aerobic condition the material is turned at specific intervals for which a 60 cm wide strip on the longitudinal side of the pit is kept vacant.

Concept-

Incineration-

• Burning of refuse at high temperatures in furnaces, called incinerators, is quite a sanitary method of refuse disposal and is widely adopted in developed countries. 
• Incineration is a method in which disposal of refuse is carried out by burning it at high temperature either in presence of oxygen.
• There is no odour trouble or dust nuisances.
• It requires very less space.

Disadvantages-

• It is a very costly method and requires a lot of technical knowledge.
• Solid waste to be burnt should have a high calorific value.

Composting-

• It is a biological method of decomposing solid wastes.
• This can be done in both aerobic and anaerobic conditions.
• Inorganic materials like plastics, rubber, and leather are separated from municipal solid wastes and the entire process involving both separation and bacterial conversion of the solid wastes is known as composting.
• So it is limited to special wastes and selected materials.

Sanitary Landfill-

• In this method of refuse of disposal, refuse is carried and dumped into the low-lying area under an engineered operation, designed and operated in an environmental manner as not to cause any public nuisance or hazards to public health or safety.
• This method is most simple and economical.
• No separation is required and no byproducts are left out or evolved in this method.

Disadvantages-

• The continuous evolution of foul gases near the fill site. These gases may often be explosive in nature and are produced by decomposing organic matter.
• During the rainy season when excess water seeping through the area may come out of the dump as a coloured liquid called leachate.
• Rat and fly breeding also occurs here.

Salvage by sorting-

• Waste sorting is the process by which waste is separated into different elements.
• Waste sorting can occur manually at the household and collected through curbside collection schemes, or automatically separated in materials recovery facilities or mechanical biological treatment systems.
• In salvage by sorting process, it requires presorting, grinding and turning.

Explanation:

Leachate

• As rainwater infiltrates through landfill waste, it becomes contaminated with dissolved and suspended matter originating from the decomposing waste.
• Leachate that escapes from a landfill can contaminate groundwater, surface waters, and soil, potentially polluting the environment and harming human health.
• The composition of the resulting leachate varies according to the nature of the landfill material, which may include biodegradable, non-biodegradable, organic/inorganic, and toxic/non-toxic waste.

Explanation:

Landfill or Burying:

• Landfill refers to the disposal of waste material by burying it.
• It is an extended storage area for non-biodegradable waste.
• Landfill is an area, which prevent contamination from the waste entering the area surrounding by soil and water and it also helps to reduce odor and pests

Incineration:

• This method involves burning of solid wastes in a furnace until the wastes are turned into ashes
• In this process, the combustible portion of the waste is combined with oxygen forming carbon dioxide and water, which are released into the atmosphere
• Incinerators are made in such a way that they do not give off extreme amounts of heat when burning solid wastes
• Suitable temperature and operating conditions are required to achieve for incineration
• It reduces the volume of waste up to 20 or 30% of the original volume
• This method of solid waste management can be done by individuals, municipalities and even institutions

Pulverization 

• It refers to the action of crushing and grinding heavier solids into the lighter solids.

Composting 

• It is a natural biological process, carried out under controlled aerobic conditions (requires oxygen).
• In this process, various microorganisms, including bacteria and fungi, break down organic matter into simpler substances.
• The effectiveness of the composting process is dependent upon the environmental conditions present within the composting system i.e. oxygen, temperature, moisture, material disturbance, organic matter and the size and activity of microbial populations.