What is the acceptable range of biological oxygen demand in drinking water?
Typical values. Most pristine rivers will have a 5-day carbonaceous BOD below 1 mg/L. Moderately polluted rivers may have a BOD value in the range of 2 to 8 mg/L. Rivers may be considered severely polluted when BOD values exceed 8 mg/L.
What is the optimum value of BOD in ppm?
Statement I : The value of the parameter “Biochemical Oxygen Demand (BOD)” is important for survival of aquatic life. Statement II : The optimum value of BOD is 6.5 ppm.
What is a high BOD value?
Higher BOD indicates more oxygen is required, which is less for oxygen-demanding species to feed on, and signifies lower water quality. Inversely, low BOD means less oxygen is being removed from water, so water is generally purer.
What is the range of bod?
BOD values range widely; generally, pristine waters have a value below 1 mg l−1, moderately polluted waters 2–8 mg l−1, and treated municipal sewage 20 mg l−1. Standards for the discharge of effluent from WWTPs have the range 20–30 mg l−1 and require a minimum flow in receiving waters to ensure sufficient dilution.
What is BOD Toppr?
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. Answer verified by Toppr.
What is BOD class 9th?
Biological Oxygen Demand is defined as the amount of dissolved oxygen required by aerobic microorganisms to breakdown the organic materials in a sample of water at a specific temperature & timeframe.
What is BOD short answer?
Biochemical oxygen demand (BOD) represents the amount of oxygen consumed by bacteria and other microorganisms while they decompose organic matter under aerobic (oxygen is present) conditions at a specified temperature. The decay of organic matter in water is measured as biochemical or chemical oxygen demand.
What is bod A The amount of O 2 Utilised by organisms in water b the amount of o2 utilized by micro organisms for decomposition C the total amount of O 2 present in water D All of the above?
– The value of BOD is expressed in milligrams of oxygen consumed per liter of sample during 5 days of incubation at 20 ∘C. Utilized by microorganisms for decomposition. Hence Option ‘B’ is the correct answer.
How is BOD removed from wastewater?
Some BOD is removed in the septic tank by anaerobic digestion and by solids which settle to the bottom of the septic tank, but much of the BOD present in sewage (especially detergents and oils) flows to the leaching field.
What is COD level in water?
COD is a measure of the oxygen equivalent of the organic matter in a water sample that is susceptible to oxidation by a strong chemical oxidant. COD is widely used as a measure of the susceptibility to oxidation of the organic and inorganic materials present in water bodies and in the municipal and industrial wastes.
What is COD and BOD in water?
COD or Chemical Oxygen Demand is the total measurement of all chemicals (organics & in-organics) in the water / waste water; BOD is a measure of, the amount of oxygen that require for the bacteria to degrade the organic components present in water / waste water.
What is the limit of cod?
| Parameter | Unit | Maximum permissible limit |
|---|---|---|
| Chemical Oxygen Demand (COD) | mg/l | 120 |
| Biochemical Oxygen Demand (BOD5) | mg/l | 40 |
| Chloride | mg/l | 750 |
| Sulphate | mg/l | 750 |