What is biodegradability index?

What is biodegradability index?

The biodegradability index (BI) is an indicator of the toxicity of the wastewater and is defined as the ratio between BOD and COD. Its value varies from zero to unity. For the complete biodegradation of an effluent, its BI value must be above 0.3.

What is BOD and COD ratio?

The ratio COD/BOD is defined as the portion of biodegradable organics compared to total (bio + non bio) degradable organics. This ratio is generally greater than 1, but can be equal to 1 if sample has only biodegradable organics.

How is COD BOD ratio calculated?

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.

Is TOC greater than COD?

It is obvious that if TOC is high then, COD is also high, but the reverse relation may not be true ie, If COD is high it does not mean that TOC will be high. COD may be high due to presence of inorganic reducing substances and in that case TOC may be less.

What is BOD and COD PDF?

Definition. BOD: BOD is the amount of oxygen consumed by bacteria while decomposing organic matter under aerobic conditions. COD: COD is the amount of oxygen required for the oxidation of total organic matter in water.

Is BOD higher than COD?

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.

Which one is better BOD or COD?

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

Why is BOD COD ratio important?

Results of the investigation revealed that BOD: COD ratio is a good indicator for pollution measurement in river. It can be used as an indicator to predict the relationship of BOD and COD in the river. It is also found to be reliable and useful indicator to relate organic matter content in the river water.

What is difference between BOD and COD and TOC?

COD or Chemical Oxygen Demand is the total measurement of all chemicals in the water that can be oxidized. TOC or Total Organic Carbon is the measurement of organic carbons. BOD- Biochemical Oxygen Demand is supposed to measure the amount of food (or organic carbons) that bacteria can oxidize.

What is the relationship between TOC and COD?

The study concludes that TOC can be reliably used for the generic replacement of both COD (COD=49.2+3.00*TOC) and BOD5 (BOD5=23.7+1.68*TOC) in influent wastewaters but only for COD (COD=7.25+2.99*TOC) in final effluents.

What is the BOD value of pure water?

about 1 ppm value
UPLOAD PHOTO AND GET THE ANSWER NOW! Solution : A pure water would have about 1 ppm value. A water supply with BOD level of 3.5 ppm is moderately clean, and water with a BOD level of 6.9 ppm is considered as polluted water.

What is a good BOD?

A BOD level of 1-2 ppm is considered very good. There will not be much organic waste present in the water supply. A water supply with a BOD level of 3-5 ppm is considered moderately clean.

What is TOC ratio in COD?

The COD/TOC ratio for all compounds ranges between 0 and 5.33, and is a direct measure of the average oxidation state of the carbon in a specific compound or waste sample. The higher the COD/TOC ratio, the more impact the compound or waste sample will have on the surface water oxygen concentration.

What does TOC mean in wastewater?

Total Organic Carbon (TOC) is a measure of the total amount of carbon in organic compounds in pure water and aqueous systems. TOC is a valued, analytical technique that is applied by organizations and labs to determine how suitable a solution is for their processes.