What Is Bod Water

The decay of organic matter in water is measured as biochemical or chemical oxygen demand. BOD is a measure of the amount of oxygen required to remove waste organic matter from water in the process of decomposition by aerobic bacteria (those bacteria that live only in an environment containing oxygen).

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.

How does BOD affect water quality?

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.

What does COD mean in wastewater?

The chemical oxygen demand (COD) is a measure of water and wastewater quality. The COD test is often used to monitor water treatment plant efficiency.

What is the BOD of pure water?

Answer. The BOD of pure water is 1ppm and if it is greater than 17ppm then it is polluted water.

What is BOD and do in water?

BOD is a measure of the amount of oxygen required to remove waste organic matter from water in the process of decomposition by aerobic bacteria (those bacteria that live only in an environment containing oxygen). BOD is used, often in wastewater-treatment plants, as an index of the degree of organic pollution in water.

What happens if cod is high?

Higher COD levels mean a greater amount of oxidizable organic material in the sample, which will reduce dissolved oxygen (DO) levels. A reduction in DO can lead to anaerobic conditions, which is deleterious to higher aquatic life forms.

In which water bod is maximum?

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. Municipal sewage that is efficiently treated by a three-stage process would have a value of about 20 mg/L or less.

What is BOD and COD?

BOD means Biochemical oxygen demand. The microorganisms use organic matter as a food source through oxidation which oxygen is consumed. COD, Chemical Oxygen Demand, is a measure of the total quantity of oxygen required to oxidize all organic material into carbon dioxide and water.

How is bod calculated?

BOD is computed based on the difference between initial and final D.O. The test uses dilution water and a known amount of sample in a 250-300 ml incubation bottle. The initial D.O. is measured by probe and the bottle is stored at 20 °C. After five days, final D.O. is measured.

How do you test COD in wastewater?

The COD test uses a chemical (potassium dichromate in a 50% sulfuric acid solution) that “oxidizes” both organic (predominate) and inorganic substances in a wastewater sample, which results in a higher COD concentration than BOD concentration for the same wastewater sample since only organic compounds are consumed

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 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 a good BOD level?

A BOD level of 1-2 ppm is considered very good. There will not be much organic waste present in the water supply. A water supply with a BOD level of 3-5 ppm is considered moderately clean.

What is BOD removal?

BOD is fairly easy to remove from sewage by providing a supply of oxygen during the treatment process; the oxygen supports bacterial growth which breaks down the organic BOD. Reduction of BOD is a relatively easy and efficient process, and results in sewage of low BOD flowing to the leaching field.

What is the difference between BOD and COD in wastewater?

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.

Why is bod done for 5 days?

Higher the BOD value higher is the water polluted. The reason for taking 5 days BOD as standard is due to the following fact: The “Dissolved Oxygen” present in water gets used for the decomposition of organic matter as well as nitrogenous matter. From the combined BOD curve, we have two oxygen demands: 1.

How do you reduce BOD in water?

These are the best practices for reducing BOD and TSS that facility managers should know:

1. Focus on removing TSS from wastewater first.
2. Get a properly sized EQ tank.
3. Control the pH of the waste stream.
4. Install a modern plate pack DAF made of stainless steel or plastic.
5. Use a regenerative turbine air dissolution pump.

How do you do a BOD experiment?

Procedure

1. Collect the water sample from a pond.
2. Carefully fill a BOD bottle with sample water without making air bubbles.
3. Add 2ml of manganese sulfate to the BOD bottle carefully by inserting the pipette just below the surface of water.
4. Add 2 mL of alkali-iodide-azide reagent in the same manner.

Why is COD higher than BOD?

COD stands for ‘Chemical Oxygen Demand’ where BOD stands for Biochemical Oxygen Demand. COD is normally higher than BOD because more organic compounds can be chemically oxidised than biologically oxidised.

Why BOD is important?

It represents the quantity of oxygen which is consumed in the course of aerobic processes of decomposition of organic materials, caused by microorganisms. The BOD therefore provides information on the biologically-convertible proportion of the organic content of a sample of water.

What is BOD treatment?

Biological Oxygen Demand (BOD) is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic biological organisms “bio-bugs” in a body of water to break down organic material present in a given water sample at a certain temperature over a specific time period.