Advertisements
Advertisements
प्रश्न
Water samples were collected at points A, B and C in a segment of a river near a sugar factory and tested for BOD level. The BOD levels of samples A, B and C were 400 mg/L, 480 mg/L and 8 mg/L respectively. What is this indicative of? Explain why the BOD level gets reduced considerably at the collection point C?
Advertisements
उत्तर
At collection points A and B, the BOD level is high due to high organic pollution caused by sugar factory and sewage discharge.
At the collection point C, the water was released after secondary treatment/ biological treatment (where vigorous growth of useful aerobic microbes into flocs consume the major part of the organic matter present in the river water or effluent due to sugar factory and sewage discharge).
APPEARS IN
संबंधित प्रश्न
What are the various constituents of domestic sewage?
The polluting strength of sewage is usually characterized by its ______.
Which of the following exhibits biomagnification?
Which one of the following impurities is easiest to remove from wastewater?
Name an industry which can cause both air and thermal pollution and as well as eutrophication.
What is an algal bloom?
What do you understand by biomagnification?
What are the three major kinds of impurities in domestic wastewater?
How has DDT caused decline in bird population?
Observe figure and answer the following questions.
Biomagnification of DDT in an aquatic food chain
- What ecological term is used to describe the DDT accumulation at different trophic levels?
- List any one effect of DDT accumulation on birds
- Will DDT accumulation lead to eutrophication?
- Does it affect the BOD?
- Name disease caused by accumulation of any heavy metal.
