Table of Contents
What is the BOD value of polluted water?
Polluted water has a BOD value in the range of 6 – 9 ppm. In polluted water, some organic waste is present.
What causes high BOD in water?
High biochemical oxygen demand can be caused by: high levels of organic pollution, caused usually by poorly treated wastewater; high nitrate levels, which trigger high plant growth.
What amount of BOD indicates high water pollution Mcq?
When the amount of BOD is more than equal to 4000mg/liter, it indicates high water pollution.
Does BOD indicates the extent of water pollution by organic wastes?
Question : Assertion: BOD indicates the extent of water pollution by organic wastes. “Assertion: BOD indicates the extent of water pollution by organic wastes. Reason: Increase in BOD decreases dissolved oxygen of wastewater.”
Is BOD less than cod?
BOD measures the amount of oxygen required by the aerobic organisms to decompose organic matter and COD measures the oxygen required to decompose organic and inorganic constituents present in the wastewater by chemical reaction. Hence, the value of COD is greater than BOD.
What is the environmental significance of BOD?
Significance of BOD BOD finds its primary importance in sewage treatment plants. It gives the respiration rate of sewage, sludge, soil, garbage. It determines the rate of respiration in living beings. Measuring BOD gives the COD or Chemical Oxygen Demand of inorganic substances.
What is BOD how it causes pollution?
Biochemical Oxygen Demand (BOD) is a measure of the oxygen used by microorganisms to decompose waste. The more organic waste present, the more bacteria there are decomposing this waste and using oxygen, so the BOD level will be high. The oxygen may diminish to levels that are lethal for fish and aquatic insects.
What is the BOD level of water pollution?
BOD level is a common metric for water pollution. The BOD level is determined by comparing the dissolved oxygen levels of a water sample before and after 5 days of incubation in the dark (see the next section for this). The difference between the two DO levels represents the amount of oxygen required for the decomposition
What does a high BOD in water indicate?
Whereas a high BOD indicates polluted water as in that water the dissolved oxygen is consumed by bacteria. So, the correct option is ‘more, less’ Answer verified by Toppr Upvote (0)
How does BOD affect dissolved oxygen levels?
When BOD levels are high, dissolved oxygen (DO) levels decrease because the oxygen that is available in the water is being consumed by the bacteria. Since less dissolved oxygen is available in the water, fish and other aquatic organisms may not survive.
What are the effects of pollution of water?
Polluting water directly harms every living creature be it mankind or the other forms of life. Rising biochemical oxygen demand levels in water are harming the ecosystem of the water bodies which indirectly is harming the whole ecology of the whole biosphere as a whole. It is our duty to keep these ecosystems alive.