The term "biochemical oxygen demand" or BOD refers to how much oxygen is consumed by bacteria and other microorganisms, while breaking down organic matter in aerobic (oxygen present) conditions at a particular temperature.
What is BOD in water and How is BOD determined?
The biochemical oxygen demand (BOD) of water controls how organisms in a particular habitat, are impacted by decomposing materials. The amount of oxygen needed by bacteria to break down organic matter is determined by BOD measurement.
Biochemical oxygen demand's sources
Sources of biochemical oxygen demand include topsoil, leaves, and woody debris, animal dung, effluents from pulp and paper mills, wastewater treatment facilities, feedlots, and food-processing facilities, malfunctioning septic systems, and urban stormwater runoff.
It is frequently used to determine the organic quality of water even though it is not a perfect quantitative test. It is regularly used as a trustworthy surrogate for the level of organic pollution in water, and is most frequently represented in milligrams of oxygen used per litre of sample over 5 days of incubation at 20°C (BOD-5).
What does BOD represent?
The biological oxygen requirement directly influences the amount of dissolved oxygen, in rivers and streams. The rate of oxygen consumption is influenced by a number of factors, including temperature, pH, the presence of specific bacteria, and the kinds of organic and inorganic materials in the water.
The rate of oxygen loss in the stream increases with the value. Higher aquatic life forms therefore have less oxygen available to them. The effects of high BOD levels on aquatic creatures are the same, as those of low dissolved oxygen levels: stress, suffocation, and death.
Biological oxygen demand is influenced by the same variables as dissolved oxygen
Two measures must be taken to determine the biochemical oxygen demand. The initial measurement of dissolved oxygen is done on the first sample, and the subsequent measurement is done on the second, after it has been incubated in the lab for five days (final).
This is the quantity of oxygen needed by microorganisms to decompose the organic matter in the sample, during the incubation period.
Importance of BOD Removal
All communities must do the beneficial and essential task of wastewater treatment. Effective water treatment is necessary to prevent harm to human health and the local ecosystem, when water is released back into the environment.
Bacteria are required for the disintegration of chemicals; however, an excess of BOD might lead to an overabundance of bacteria. Additionally, it can lower the oxygen content of receiving waterways, causing fish deaths and environmental damage. Controlling the BOD level at each stage of the treatment process is essential, as is getting rid of as much as you can in the last phases.
BOD removal technologies
Water with high COD/BOD levels can be produced by industrial processes and municipal wastewater discharge, needing careful treatment before discharge to preserve rivers.
Aerated treatment (oxygen-rich environment), anaerobic treatment (no oxygen), activated sludge, and membrane bioreactors, are examples of secondary treatment methods for BOD removal.
Three typical techniques for BOD reduction in wastewater treatment are as follows:
1. Clarification of wastewater
2. Separation of wastewater (Coagulation & Flocculation)
3. Microbial decomposition in anaerobic environments
The operator needs to be familiar with both accepted practises and relevant technical material. The test offers a reliable characterisation of wastewater when applied properly. Although the 3 or 5 day wait time for the test limits its effectiveness as a control tool, it is anticipated to be a standard for regulatory bodies for many years.
What do we offer?
Specialized wastewater management is necessary because wastewater composition varies. The best method for enhancing water quality is chosen with Netsol Water experts, because every project is unique.