How is BOD different from do?

Hint: DO are dissolved oxygen and BOD are biochemical oxygen are certain parameters by which one can find out the degree of water pollution or the concentration of readily biodegradable organic matter in the water bodies.

What is difference between BOD and dissolved oxygen?

Difference between Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) Biochemical oxygen demand (BOD) is the amount of oxygen microorganisms require to break down organic materials. In contrast, chemical oxygen demand (COD) is the amount of oxygen required to break down the organic material via oxidation.

What is DO and BOD in biology?

BOD is the biological method used for the measurement of the total amount of dissolved oxygen (DO) used by microbes in the biological process of metabolizing organic molecules present in water. The total amount of oxygen gas present in the water is called dissolved oxygen (DO).

What is BOD and how does it affect do?

Biological oxygen demand directly affects the amount of dissolved oxygen in rivers and streams. The rate of oxygen consumption is affected by a number of variables: temperature, pH, the presence of certain kinds of microorganisms, and the type of organic and inorganic material in the water.

Can BOD be higher than do?

No, BOD is always less or equal to COD, since BOD gives you only the biodegradable organic content of a aquatic sample, while COD gives you the biodegradable and the non-biodegradable organic content, thus the total organic content.

BOD (biological oxygen demand) - The water quality indicator

What is the relationship between BOD and dissolved oxygen do?

BOD directly affects the amount of dissolved oxygen in rivers and streams. The greater the BOD, the more rapidly oxygen is depleted in the stream. This means less oxygen is available to higher forms of aquatic life.

Does high BOD mean low do?

The dissolved oxygen readings are usually in parts per million (ppm). 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.

How do you calculate BOD from dissolved oxygen?

What is a good level of dissolved oxygen in water?

Healthy water should generally have dissolved oxygen concentrations above 6.5-8 mg/L and between about 80-120 %.

What is do in BOD test?

Dissolved oxygen (DO) is measured at the beginning of the analysis and after a 5 day, in-the-dark, 20 'C incubation period. The difference of the DO between the beginning and end of analysis is used to calculate the BOD. The BOD test is a bioassay.

How are DO and BOD related?

BOD and DO are inversely proportional to each other i.e a decline in DO levels reflects a high level of BOD. Additional Information: -BOD test evaluates the dissolved oxygen used up by aerobic microorganisms over a 5-days period at 20℃. BOD concentration of wastewater is expressed in mg/L.

Do is a basis of BOD?

The Basis of Design (BOD) is a very important document for every project. The basis of design or project design basis provides all the principles, business expectations, criteria, considerations, rationale, special requirements, and assumptions used for decisions and calculations required during the design stage.

What is the implication of high BOD and high DO in wastewater?

IMPORTANCE FOR WASTEWATER

The higher the BOD value, the greater the amount of organic matter or “food” available for oxygen consuming bacteria. If the rate of DO consumption by bacteria exceeds the supply of DO from aquatic plants, algae photosynthesis or diffusing from air, unfavourable conditions occur.

What does dissolved oxygen mean in water?

Dissolved oxygen (DO) is a measure of how much oxygen is dissolved in the water - the amount of oxygen available to living aquatic organisms.

Why is BOD removed from wastewater?

BOD is a crucial factor in refining wastewater.

It can also drain receiving waters of oxygen which can kill fish and harm the environment. Therefore it is important to control the level of BOD at every stage of the treatment process, and to remove as much as possible in the final stages.

Why is BOD important in water?

The BOD is an important parameter for assessing water quality. It deals with the amount of oxygen consumption (mg O₂ L^{− 1}) by aerobic biological organisms to oxidize organic compounds. Sewage with high BOD can cause a decrease in oxygen of receiving waters, which in turn can cause the death of some organism.

What happens if dissolved oxygen is too high in water?

Just as low dissolved oxygen can cause problems, so too can high concentrations. Supersaturated water can cause gas bubble disease in fish and invertebrates ¹². Significant death rates occur when dissolved oxygen remains above 115%-120% air saturation for a period of time.

What happens if dissolved oxygen is too high?

Concentrations above this level can be harmful to aquatic life. Fish in waters containing excessive dissolved gases may suffer from "gas bubble disease"; however, this is a very rare occurrence. The bubbles or emboli block the flow of blood through blood vessels causing death.

What are 3 factors that influence dissolved oxygen levels?

What are the 4 types of BOD?

BOD technically stands for Biological Oxygen Demand BOD5 means the test has been run for 5 days. C-BOD means only the Carbonaceous Biochemical Oxygen Demand N-BOD means Nitrogenous Biochemical Oxygen Demand BOD5 typically includes C-BOD and N-BOD unless one or the other is inhibited.

What is a normal level of BOD in water?

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.

Can you convert BOD to COD?

Typically, the average BOD result is divided by the average COD result to find a "conversion factor" between the two parameters. One would then multiply their COD results by this factor to estimate BOD. COD values are almost always higher than BOD values for the same sample.

What does it mean if BOD is high 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.

Why a low BOD is important in wastewater treatment?

Generally, a higher BOD value indicates a higher level of water pollution, while a lower BOD value indicates less polluted, or cleaner water.

What is the best explanation for the difference between dissolved oxygen and Biochemical Oxygen Demand in a stream?

COD is the amount of oxygen required to chemically breakdown the pollutants. Whereas BOD is the amount of oxygen required to do this biologically through micro-organisms. There is a strong correlation between COD and BOD, however COD analysis is a much faster and more accurate method.