Environmental Pollution and Control in Mines - short answer questions from AMIE exams (Set 5)

Define the particulate pollutants in the atmosphere and name any four such pollutants.

"Particulate matter," also known as particle pollution or PM, is a complex mixture of tiny particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulphates), organic chemicals, metals, and soil or dust particles.
Particle Pollution includes
  • Dust
  • Dirt
  • Soot
  • Smoke
  • Drops of liquid

Give one example for each of point, line and area sources of contamination.

Point-source pollution is easy to identify. As the name suggests, it comes from a single place. Non point-source pollution is harder to identify and harder to address. It is pollution that comes from many places, all at once. Factories and power plants can be a source of point-source pollution.
A line source, as opposed to a point source, area source, or volume source, is a source of air, noise, water contamination or electromagnetic radiation that emanates from a linear (one-dimensional) geometry.  The most prominent linear sources are roadway air pollution, aircraft air emissions, roadway noise, certain types of water pollution sources.
"Area" sources consist of smaller-size facilities that release lesser quantities of toxic pollutants into the air. Area sources are defined as sources that emit less than 10 tons per year of a single air toxic, or less than 25 tons per year of a combination of air toxics.

What do you understand by the term ‘isokinetic sampling’?

Isokinetic sampling involves extracting the sample at the same velocity as the stack gas is travelling up the chimney stack or in a duct.

What is the major difference between sedimentation pond and tailing dam?

Sedimentation pond.  A man-made pond that allows contaminants in collected stormwater run-off to settle out in a controlled area before water is discharged, to reduce contamination of waterways and streams.
Tailing dam.  A tailing dam is typically an earth-fill embankment dam used to store by-products of mining operations after separating the ore from the gangue. Tailings can be liquid, solid, or a slurry of fine particles, and are usually highly toxic and potentially radioactive.

What is the value of sound pressure in microbar at the threshold of hearing (zero decibel)?

0 dB does not mean no sound, it means a sound level where the sound pressure is equal to that of the reference level. This is a small pressure, but not zero. At 0 decibel, it is 0.0002 ┬Ábar.

What do you understand by the term ‘mulching’?

The process of covering the open surface of the ground by a layer of some external material is called mulching & the material used for covering is called as ‘Mulch.’ Mulching is usually practised when cultivating commercially important crops, fruit trees, vegetables, flowers, nursery saplings, etc. It is beneficial in yard gardening, containers & raised beds of home gardens.

The solid concentration in influent and effluent is 2000 mg/1 and 50 mg/1, respectively in a sedimentation basin. Find the percentage of solids removed.
% of solids removed = [(In - Out)/(In)] x 100

What is the maximum permissible total dose in rem (Roentgen equivalent man) fixed for a radiation worker for a complete lifetime.

REM: Roentgen Equivalent Man is a measurement that correlates the dose of any radiation to the biological effect of that radiation. Occupational exposure for worker is limited to 5000 mrem per year. For the general population, the exposure is 500 mrem above background radiation in any one year.

Define wetlands and name two such areas in Indian subcontinent.

Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. There are 42 wetlands in India that have international importance and hence recognized. Examples are Ropar Wetland in Punjab and Rudrasagar Lake in Tripura.

What do you understand by the term ‘Green House Effect’?

The greenhouse effect is a natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
Greenhouse gases include water vapour, carbon dioxide, methane, nitrous oxide, ozone and some artificial chemicals such as chlorofluorocarbons (CFCs).
The absorbed energy warms the atmosphere and the surface of the Earth. This process maintains the Earth’s temperature at around 33 degrees Celsius warmer than it would otherwise be, allowing life on Earth to exist.

Give any four water quality parameters for effluents to be discharged in rivers.

  • pH
  • Chemical Oxygen Demand (COD)
  • Total Suspended Solids (TSS)
  • Oil & Grease

Define ‘phreatic surface’.

The term 'phreatic surface' indicates the location where the pore water pressure is under atmospheric conditions (i.e. the pressure head is zero). This surface normally coincides with the water table. The slope of the phreatic surface is assumed to indicate the direction of groundwater movement in an unconfined aquifer.

Why is topsoil separately stored during mining operations?

In the case of mining operations, the stockpiling process involves removal of the topsoil layer and other soil layers necessary to get to the coal that is to be mined. The topsoil is removed first and stockpiled in one pile, and the soil layer below is also removed and stockpiled separately. This subsoil layer is referred to as the overburden. 
Stockpiles are often meters deep. When mining operations are complete, the overburden material is reapplied and levelled and then the topsoil is reapplied and spread over the overburden material to provide a planting medium. 
The subsoil layers lack the organic and microbial organisms necessary to sustain plants. Mining operations often require that topsoil be stored in stockpiles for long periods of time, often several years.

What do you understand by soil amendment schemes?

Soil amendments are anything mixed into topsoil to promote healthy plant growth. They function in a number of ways. For example, they may change the pH of soil or supply nutrients.

Give the provisions regarding public hearing of environmental management plan.

Public hearing is a process in the environmental clearance process in which stakeholders can interact directly with government officials and the project proponent about the concerns regarding the upcoming project. In this way people can express their objections and opinions, and offer suggestions on a proposed undertaking in order to influence the decision-making process. Public participation may benefit both the proponent and affected community, whereas if ignored it may lead to conflicts and problems for project implementation, acceptability and sustainability.
For a project proponent, public hearing is a forum to inform the entire community of the outcome of the Environmental Assessment of the proposed project, to verify the EIA findings in relation to ground reality, and confirm that stakeholders have been adequately consulted and have been part of the decision-making processes.

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