Cod/bod Ratio

June 26, 2024 Post a Comment

Cod/bod ratio

To establish the COD:BOD ratio for your wastewater, simply have both COD and BOD run on several wastewater samples. Divide the COD concentration by the BOD concentration for each sample and average the results.

What does a high BOD COD ratio mean?

BOD to COD ratio: It signifies the quality of wastewater with respect to the type of organic matter present in it that is either biodegradable or non-biodegradable. If the value of this ratio high that means the biodegradable organic matter is high and vice-versa.

Is BOD COD ratio less than 1?

BOD is oxygen demand for oxidation of organic matter by micro organism. COD is oxygen demand for oxidation of organic and non biodegradable organic matter. COD is always greater than BOD hence the ratio will be always greater than 1. If BOD/COD is 0.92 to 1, waste water is fully biodegradable.

How do you convert BOD to COD?

Typically, the average BOD result is divided by the average COD result to find a "conversion factor" between the two parameters. One would then multiply their COD results by this factor to estimate BOD. COD values are almost always higher than BOD values for the same sample.

What is COD & BOD in water?

The biochemical oxygen demand (BOD) represents the amount of dissolved oxygen (DO) consumed by biological organisms when they decompose organic matter in water. The chemical oxygen demand (COD) is the amount of oxygen consumed when the water sample is chemically oxidised.

What is BOD formula?

BOD is calculated after 5 days of incubation of a sample maintaining 20 degrees centigrade and expressed as milligrams of oxygen consumed per litre of sample. The formula for BOD calculation is, BOD = [ D(i) – D(f) ]/P.

What is the normal COD value?

The COD of surface water normally ranges from 5 to 20 mg l−1. The COD as standardized method has found its way into wastewater legislation.

Is higher or lower BOD better?

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.

How do you reduce BOD COD wastewater?

Hydrogen peroxide (H2O2) has been used to reduce the BOD and COD of industrial wastewaters for many years.

Which is good BOD or COD?

COD is always higher than BOD because chemical oxidation is easier than biological oxidation.

What is BOD limit?

As per the World Health Organisation, a limit of less than 5.0 mg/l is ideal for water bodies. At this limit BOD will not cause any harmful impacts on the human body, wastewater sewage must have BOD around 80 ppm and COD 200 ppm for discharge.

What is COD to N ratio?

Influent chemical oxygen demand/nitrogen (COD/N) ratio is used to control fouling in membrane bioreactor (MBR) systems. However, COD/N also affects the physicochemical and biological properties of MBR biomass.

How COD is calculated?

There is a formula for calculating COD. Consider the formula for COD calculation: (a - b) X C X 8,000 / the volume of the sample in mL. Let "a" represent the titrant used for your sample expressed in mL. Let "b" represent the titrant used for your blank sample in mL.

What is TDS BOD and COD?

Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) reduction of the textile effluent treated for 15 days with Candida tropicalis and Candida apis Values are means ± standard error of two determinations.

What is BOD water quality?

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).

Who limits COD in water?

The waste water of tannery having COD upto 55000 mg/L with the Cr III upto 150 mg/L. After conventional treatment, COD can be reduced upto 5000 ppm. The discharge limit of COD is upto 150 mg/L.

Why is BOD done for 5 days?

BOD occurs in 2 general stages. While calculating the oxygen demand, the carbonaceous stage is taken into account. This stage is almost completed in 5 days, which means that most of the organic content of the sewage is oxidized under aerobic conditions in 5 days. Hence ,BOD for 5 days is calculated.

What is a good BOD value?

BOD values range widely; generally, pristine waters have a value below 1 mg l−1, moderately polluted waters 2–8 mg l−1, and treated municipal sewage 20 mg l−1.

Is BOD equal to COD?

COD is closely related to BOD or Biochemical Oxygen Demand, the difference being that BOD is a test of the level of organic matter that can be biologically oxidised while COD is a test of the amount of organic matter that can be chemically oxidised.

What are the 4 types of BOD?

BOD technically stands for Biological Oxygen Demand BOD5 means the test has been run for 5 days. C-BOD means only the Carbonaceous Biochemical Oxygen Demand N-BOD means Nitrogenous Biochemical Oxygen Demand BOD5 typically includes C-BOD and N-BOD unless one or the other is inhibited.