Tag: biology

The Ganges river basin is one of the most fertile and densely populated regions in the world that covers an area of 1,80,000 $km^2$. The river flows through 29 cities with population over 100,000; 23 cities with population between 50,000 and 100,000, and about 48 towns. 

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The BOD measures the amount of oxygen consumed by biochemical oxidation of waste contaminants. The total amount of oxygen consumed when the biochemical reaction is allowed to proceed to completion is called as the ultimate BOD. The BOD is universally adopted as a measure of relative pollution effect.

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. 

Biochemical oxygen demand is a measure of the quantity of oxygen used by microorganisms (e.g., aerobic bacteria) in the oxidation of organic matter. Natural sources of organic matter include plant decay and leaf fall. However, plant growth and decay may be unnaturally accelerated when nutrients and sunlight are overly abundant due to human influence. Urban runoff carries pet wastes from streets and sidewalks, nutrients from lawn fertilizers; leaves, grass clippings, and paper from residential areas, which increase oxygen demand. Oxygen consumed in the decomposition process reduces other aquatic organisms of the oxygen they need to live. If dissolved oxygen concentrations drop below 5 parts per million (ppm), fish will be unable to live for very long. This can occur in the form of organic pollution for sources such as domestic sewage, septic tank leakage, and fertilizer runoff, or could be in the form of inorganics from domestic or industrial sources. 

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. 

Biological oxygen demand (BOD) is one of the most common measures of pollutant organic material in water. BOD indicates the amount of putrescible organic matter present in water. Therefore, a low BOD is an indicator of good quality water, while a high BOD indicates polluted water. The BOD test serves an important function in stream pollution-control activities.

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic microorganisms to break down organic material present in a given water sample at certain temperature over a specific period of time. Thus, the correct answer is option C.

BOD is abbreviated form of biological oxygen demand. It is the amount of oxygen required by microbes to break down the organic matter present in a certain volume of a sample of water. The amount of BOD in the water is a measure of a number of organic pollutants in the water.

C.O.D. stands for chemical oxygen demand. It is the measurement of the pollution which is based on the chemical decomposition of organic and oxidation of the inorganic contaminants present in dissolved water. It is mainly used against waste water which is contaminated by domestic and industrial wastes.