Table of Contents
What is Biochemical Oxygen Demand?
Biochemical oxygen demand (BOD) is a measure of the amount of oxygen that is required to break down organic matter in a given water sample. The higher the BOD, the higher the level of organic pollution in the water.
Measuring Biochemical Oxygen Demand
- Biochemical oxygen demand (BOD) measure of the amount of oxygen needed to break down organic matter in water. The higher the BOD, the greater the amount of organic matter in the water and the more pollution it is likely to cause.
- The BOD usually measured in milligrams per liter (mg/L) of water. The test performed by adding a known amount of glucose to a sample of water and incubating it for five days. However, the amount of oxygen consumed by the bacteria that break down the glucose then measured.
Typical Values of BOD and its Indication
- The BOD of a water sample is a measure of the amount of oxygen that used up by microorganisms in the sample over a five-day period. The higher the BOD of a water sample, the greater the amount of organic material present in the water and the greater the potential for water pollution.
- The BOD of a water sample used to indicate the level of water pollution present in the sample. A high BOD indicates that the water is polluted and that it may be difficult to treat. A low BOD indicates that the water is not polluted and however it indicates that it may be easier to treat.
Factors Affecting BOD
The factors affecting BOD include the type and amount of organic material present, the temperature, the pH, the dissolved oxygen concentration, and also the presence of bacteria.
Significance of BOD
The significance of BOD is that it is a measure of the amount of dissolved oxygen that is used up by microorganisms as they break down organic matter in water. The higher the BOD, the more oxygen that is being use up and the more polluted the water is. This makes BOD an important indicator of water quality.
Sources of BOD
Sources of BOD include municipal and industrial wastewater discharges, agricultural runoff, and leachate from landfills.
Usage of BOD in Sewage Treatment Plants
- The biochemical oxygen demand (BOD) measure of the amount of oxygen consumed by microorganisms in a sample of water over a five-day period. However, the BOD is a good measure of the amount of organic matter in the water.
- The BOD used in the design of sewage treatment plants. The plant designed to have a capacity that is equal to the BOD of the wastewater.
Effect of High BOD on the Aquatic Ecosystem
The impact of high BOD on the aquatic ecosystem is significant because it can lead to the death of aquatic life. The high levels of BOD can deplete the dissolved oxygen levels in the water, which can cause fish and other aquatic life to suffocate. Additionally, the high levels of BOD can cause the water to become cloudy and murky, making it difficult for aquatic life to thrive.
Pollution and Its Effects on Biochemical Oxygen Demand
- There are a variety of pollutants that can impact biochemical oxygen demand (BOD), including municipal and industrial wastewater, agricultural runoff, and septic tank effluent.
- BOD is a measure of the amount of oxygen that needed to break down organic matter in water. However, the higher the BOD value, the greater the amount of oxygen that required to degrade the organic matter. Pollutants that reduce dissolved oxygen levels can cause a spike in BOD values.
- Eutrophication can also lead to the growth of harmful algae blooms. These blooms can produce toxins that can be harmful to both humans and aquatic life.
Methods to Reduce BOD in Water
There are many ways to reduce BOD in water. Some methods are more expensive than others, but all can be effective in reducing the amount of BOD in a water system.
1. Use a septic tank or other wastewater treatment system.
Septic tanks and other wastewater treatment systems designed to reduce the amount of BOD in wastewater. They can be expensive to install, but they are a very effective way to reduce BOD.
2. Use a filter system.
A filter system can be used to remove particles from water that can contribute to high levels of BOD. This is a less expensive option than a septic tank or other wastewater treatment system, but it is not as effective.
3. Use a bioreactor.
A bioreactor is a type of wastewater treatment system that uses microorganisms to break down organic matter. This is a more expensive option than a septic tank or a filter system, but it is more effective at reducing BOD.
