bod versus cod: COD BOD TSS Analyser,manufacturer And suppliers,Pune,india


The dissolved oxygen depletion due to organic matter leads to adverse and fatal effects on aquatic life, unpleasant odour and bad taste. Effluent treatment plant normally contains primary, secondary and tertiary treatment methods. In primary methods, coarse solids are removal by screens or primary sedimentation. Many investigations are reported on parameter studies in suspended growth and activated sludge process for removal of organic matter from effluents. Attached growth of the microorganism rather than suspended mechanism differentiates these from activated sludge processes. Membrane separation is also one of the important methods for desalination and water purification.[8-13] Other methods include mainly electro dialysis and chemical treatments.

decomposition of organic

Bioflocculant produced by Bacillus velezensis and its potential … –

Bioflocculant produced by Bacillus velezensis and its potential ….

Posted: Wed, 29 Jun 2022 07:00:00 GMT [source]

A first peak of flow usually happens in the late morning, when wastewater from the height morning water use reaches the treatment plant, and a second peak move usually happens in the night. The relative magnitude of the peaks and the times at which they happen range from country to country and with the dimensions of the group and the length of the sewers. Biological oxidation can oxidise natural organic debris and organic waste in water. COD is evaluated by incubating a closed water sample for a set period of time with a strong oxidant such as potassium dichromate in combination with boiling sulphuric acid at a specific temperature. To break down the organic materials in the water, bacteria will need to take in oxygen. The test determines whether incoming water has the ability to decrease the oxygen in receiving waters due to bacterial activity.

Aerobic wastewater treatment

It gradually becomes less after certain time, the effect of contact time diminishes. The Langmuir equation indicated better fit for the batch experimental data than Freundlich equation. BOD is a measure of the amount of oxygen that require for the bacteria to degrade the organic components present in water / waste water. MS-4111 UVI is the first full-spectrum ( nm) immersion UV analyzer.Apply to measurement COD, BOD, TSS, color and other indicators of surface water, groundwater, municipal wastewater. Measurement of Sediment oxygen demand is a measure of the oxygen demand characteristics of the bottom sediment which affects the dissolved oxygen resources of the overlying water.

organic materials

BOD stands for Biological Oxygen Demand, and it represents the oxygen consumed by the microorganisms and bacteria to decompose organic matter under the biological reaction – aerobic process. The water test is pretty simple for BOD; all you have to do is put some sample water in a bottle and leave it under certain weather conditions for a duration of five days. In comparison to COD, the value for BOD is low, as it is used for wasting loading in treatment plants. The waste water from nearby common effluent treatment plant was used for the investigation. The initial COD was determined by using potassium dichromate as oxidizing agent and COD digestion apparatus (spectralab-make). The adsorbents were prepared by washing the raw material with distilled water.

Natural and organic waste and detritus from the wastewater treatment plants, failing urban runoff, septic system and agriculture, whole system act as the source food for the bacteria borne in water. Thyes Bacterial decomposes that organic waste using the dissolved oxygen.Biological Oxygen Demand and Chemical Oxygen Demand both are main properties that show characteristic and strength of sewage. By using these BOD & COD the oxygen demand in wastewater tested during treatment in Sewage Treatment Plant.

Most of the colloids remain suspended in solution because they have a net negative charge that causes the particles to repel each other. The charge of colloidal particles can be removed by the addition of a coagulant. The addition of coagulant neutralizes the colloidal charge, allowing the particles to come together to form larger particles that are easily removed by settling and filtration. Large quantities of floating objects like Cans, Cloths, Wood, etc present in wastewater are usually removed through screens. Different types of screens are available which include bar screens, hand-raked or mechanical raked screens, drum screens,s and wire rope screens. Sometimes instead of screening, the large-sized objects are grounded with the help of a circular grinder called Communicator to a fine size that is removed later in a settling tank.

Biological Oxygen Demand, Chemical Oxygen Demand, Total Suspended Solid

To measure SOD, a bottom sample is especially designed to entrap and seal a known quantity of water at the river bottom. Changes in DO concentrations in the entrapped water are recorded by a DO probe fastened in the sampler. In the secondary treatment, Nitrogen present in the wastewater is converted to nitrates.

A strong oxidizing agent is used to oxidize the material instead of microorganism as in case of BOD. The COD value will always be higher than the value of BOD for waste water. Natural organic detritus and natural waste from waste water treatment crops, failing septic techniques, and agricultural and urban runoff, acts as a meals source for water-borne bacteria.


The amount of dissolved oxygen used up by aerobic microorganisms to decompose the organic matters present in a sample of water is termed Biochemical Oxygen Demand or Biological Oxygen Demand . BOD and DO are inversely proportional to each other i.e a decline in DO levels reflects a high level of BOD. The major focus of wastewater treatment plants is to scale back the BOD within the effluent discharged to pure waters. Wastewater therapy vegetation are designed to function as micro organism farms, where micro organism are fed oxygen and natural waste. The extra micro organism grown in the system are removed as sludge, and this “strong” waste is then disposed of on land.

Use of Polymer flocculants for industrial waste

The biological oxygen demand is referred to as BOD, and the chemical oxygen demand is referred to as COD. Mentioned below is the list of benefits to prove why enzymatic wastewater treatment is best for reducing BOD and COD. There are quite a few terminologies applied in estimating parameters during biological waste water remedy. BOD was initially used in nineteenth Century Britian and is usually reported because the BOD5. The ‘5’ was used as no stream in Britian took greater than 5 days to reach the ocean.

activated carbon

When the slime layers become very thick they slough off and can be easily removed. After the treatment, the water may be chlorinated to kill disease-causing bacteria. It depends on the remedy process i.e if the same course of is used on a regular basis beneath the identical conditions.

bod versus cod is a type of transaction during which the recipient makes cost for an excellent at the time of supply. COD typically has shorter timeframes to supply than standard invoicing. This is helpful for the reason that customer is required by an intermediary to pay at supply.

[14-17] Adsorption is one of the most important physico-chemical treatment methods. Investigations have been reported on removal of organic matter by using various low cost adsorbents. [18-21] These studies were aimed and studying affecting parameters and isotherms and kinetics. The studies were carried out for parameters such as contact time, adsorbent dose and pH. The batch experimental data was also tested for isotherms. Organic matter removal from waste water is principle purpose behind treatment operations. Organic matter, if present in wastewater, reduces dissolved oxygen and forces the waster contaminants to undergo anaerobic decomposition.

By this process, about 90-95% of the BOD and bacteria are removed along with 10% of the phosphate and 50% of total nitrogen. Secondary treatment is done by several methods such as i) the Activated sludge process and ii) Trickling filters.  BOD- Biochemical Oxygen Demand is supposed to measure the amount of food that bacteria can oxidize. A blank sample is usually created by adding all reagents to a volume of distilled water. To ensure a true measurement of organic matter, COD is measured in both polluted water and blank samples, and the oxygen demand in the blank sample is subtracted from the COD in the original sample. If a customer is coping with a merchant in person and the customer makes a purchase order from available inventory, fee is collected on the time of sale and this could be a form of cash on delivery.

  • COD test results are used for monitoring and control of discharges, and for assessing treatment plant performance.
  • 3- BOD test happens on sealed water preserved for a period of 5 days and 20 degree Celsius temperature.
  • Then, within the description of your strategies you must clarify how you did, especially should you did some modifications.
  • The amount of Cr3+ is determined after oxidization is complete, and is used as an indirect measure of the organic contents of the water sample.
  • It does not go to completion, because the take a look at lasts only for five days.

The 5-day BOD or BOD5 is the amount of O2 consumed by microorganisms during the first 5 days of biodegradation. BOD5 test is performed by taking a sample of wastewater into a stoppered bottle, measuring the concentration of dissolved oxygen in the sample at the beginning of the test and again after 5 days. Treatment to take away wastewater constituents that may be toxic or harmful to crops, aquatic crops and fish is technically potential but is not usually economically feasible.

Cash on supply is a sort of transaction during which payment for a great is made on the time of delivery. For merchants, providing a COD cost possibility might enhance consumer confidence in a new firm that does not but have strongbrand recognition. Note that the BOD value is close to zero when the COD value is around 50 because the BOD reflects only the dissolved organics while COD contains whole dissolved natural and inorganic compounds.

  • Attached is a web page from a Masters thesis which shows the connection of measured values of BOD and COD.
  • The BOD values is dependent upon the dissolved natural matter in the waste water samples.
  • Our customised enzyme based formulation can be utilised for the anaerobic stage of the process.
  • COD is the quantity of oxygen required to chemically oxidize natural matter in your wastewater into inorganic matter.
  • To ensure a true measurement of organic matter, COD is measured in both polluted water and blank samples, and the oxygen demand in the blank sample is subtracted from the COD in the original sample.

The treatment for organic matter removal can be carried out by various physical, chemical and biological methods, in combination or separately. The most important methods in biological and physic-chemical category are activated sludge process and adsorption. The adsorption with low cost adsorbents is feasible and economical method. The studies were carried out for parameters such as contact time, adsorbent dose and pH. With adsorbent dose and contact time, the adsorption increased for initial increase and then remained constant.

Optimizing textile dyeing wastewater for tomato irrigation through … –

Optimizing textile dyeing wastewater for tomato irrigation through ….

Posted: Thu, 16 Jun 2022 07:00:00 GMT [source]

Whereas as COD – In this course of , Use of strong chemical agent is done to degrade each the organic in addition to inorganic matter current in the wastewater samples. Because COD consists of each biodegradbale and non-biodegradable substances whereas BOD accommodates solely bio-degradable. COD is all the time larger than BOD and the ratio may even exceed 2.5 depending upon the kind of water or wastewater. The ratio of COD/BOD, COD values are tending to be always higher than the BOD values and also depend in the type of water or waste waters. BOD – The quantity of oxygen required by bacteria to degrade the natural matter . COD values are generally greater than BOD, however, there isn’t any actual ratio.

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