What is the permissible limit for do in river water?

What is the permissible limit for do in river water?

The permissible limit level of dissolved oxygen in most rivers, lakes and stream that required for most aquatic organisms life is at least 5mg/l .

What is meant by BOD of water is 50 ppm?

The advised level of BOD in freshwater is 50 parts per million. This means that for per million freshwater 50 parts of organic matter is considerable, or we can say that in a one- liter sample of polluted water presence of 50 parts of the organic matter is advisable.

Is high BOD good?

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.

Is high BOD good for drinking water?

If the B.O.D. is high, that means that microorganisms are using most of the Oxygen. This situation makes it difficult for larger aquatic animals to survive. However, if the B.O.D. is low, there is an abundance of Oxygen which leads to good water quality.

What is BOD in river water?

Biochemical oxygen demand (BOD) is the amount of oxygen taken up by microorganisms that decompose organic waste matter in water. It is therefore used as a measure of the amount of certain types of organic pollutant in water.

What is BOD water?

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 are the limitations of BOD test?

Limitations Of Test The method takes five days to perform and uses a discrete sample. The test has poor reproducibility and toxic chemicals can inhibit measurement. Short-term BOD determinations magnify errors and still require relatively long sample periods. The test is not suited for on-line, continuous measurement.

What is meant by 5 day BOD test?

BOD—5. The standard oxidation (or incubation) test period for BOD is 5 days at 20 degrees Celsius (°C) (BOD5). The BOD5 value has been used and reported for many applications, most commonly to indicate the effects of sewage and other organic wastes on dissolved oxygen in surface waters (see TECHNICAL NOTE).

When the BOD value of a water sample is less than 5 ppm It indicates that water sample is?

Water considered to be pure if it has BOD less than 5 ppm whereas highly polluted water has BOD more than 17 ppm. Thus, the water having BOD less than 5 ppm is rich in dissolved oxygen.