What Is BOD 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..

How do you calculate BOD of water?

Biological Oxygen Demand (BOD): Therefore it is used to measure the amount of certain type of organic water pollution BOD is calculated by keeping a sample of water containing a known amount of oxygen for five days at 20 °C. The oxygen content is measured again and BOD is calculated.

What causes high TSS in wastewater?

High effluent suspended solids are usually caused by one of two conditions: either individual particles that will not settle are discharged or the sludge blanket in the clarifier washes out. Either of these can cause conditions 6 through 24 to occur.

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 is BOD and do in water?

Dissolved Oxygen (DO) is the amount of oxygen dissolved in the water system. … Therefore it is important to monitor the amount of DO in the water and also the BOD so it will not deplete the oxygen levels to a low and cause the system to become unhealthy and unsupportable to sustain life.

What is the BOD of safe drinking water?

Popular Answers (1) For drinking water BOD has to be less than 5 mg/L and for treated wastewater to be disposed of in the water bodies it is 30 mg/L, 100 mg/L if treated waste water is discharged into the sewerage system in India.

What does COD mean in wastewater?

chemical oxygen demandThe chemical oxygen demand (COD) is a measure of water and wastewater quality. The COD test is often used to monitor water treatment plant efficiency. … The COD is the amount of oxygen consumed to chemically oxidize organic water contaminants to inorganic end products.

How do you calculate BOD in water?

For example: 1.0 mL of a full strength wastewater sample added to 9.0 mL of DI water results in a 0.1 dilution of the wastewater. The DO concentration (mg/L) reduction must then be multiplied by 10 to determine the final BOD concentration.

What is BOD removal?

In a facility using an activated sludge process for secondary treatment, BOD is removed through the introduction of oxygen and microorganisms which consume organic material. … Microorganisms have already consumed most of the readily degradable organic matter.

How BOD test is done?

Measuring biochemical oxygen demand requires taking two measurements. One is measured immediately for dissolved oxygen (initial), and the second is incubated in the lab for 5 days and then tested for the amount of dissolved oxygen remaining (final).

What BOD means?

biochemical oxygen demandabbreviation. Definition of BOD (Entry 2 of 2) 1 biochemical oxygen demand. 2 biological oxygen demand.

How do you reduce BOD in water?

These are the best practices for reducing BOD and TSS that facility managers should know:Focus on removing TSS from wastewater first. … Get a properly sized EQ tank. … Control the pH of the waste stream. … Install a modern plate pack DAF made of stainless steel or plastic. … Use a regenerative turbine air dissolution pump.More items…•

Why is bod done for 5 days?

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. Carbonaceous BOD (initial) , 2.

What does high value of BOD indicates?

Biochemical oxygen demand or BOD is the oxygen required for microbial decomposition of a unit mass of organic remains. The degree of impurity of water due to organic matter is measured in terms of BOD. A higher BOD of a river indicates that water is highly polluted.

What is COD BOD ratio?

The BOD to COD ratio is an indicator of the proportion of biologically degradable organic matter to total organic matter.

What is BOD and COD 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 causes high BOD in water?

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.

Why is COD higher than BOD?

COD is normally higher than BOD because more organic compounds can be chemically oxidised than biologically oxidised. This includes chemicals toxic to biological life, which can make COD tests very useful when testing industrial sewage as they will not be captured by BOD testing.