What is the ratio of BOD TOC in the final effluent?
Typical values for the ratio of BOD/COD for untreated municipal wastewater are in the range from 0.3 to 0.8 (see in table 3)….
| Type of wastewater | BOD/COD | BOD/TOC |
|---|---|---|
| Final effluent | 0.1 – 0.3 | 0.2 – 0.5 |
What is BOD ratio?
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. In domestic waste the ratio between BOD/COD is 1:2. The COD/BOD ratio is useful for assessing the amount of sewage available for biological treatment.
What is the ratio between BOD and COD?
BOD : COD (Chemical oxygen demand) ratio using the formulated seed comes in the range of 0.7-0.8 whereas that using BODSEED comes in the ratio of 0.5-0.6.
How do you calculate BOD from TOC?
BOD = – 0.000364 (TOC)2+0.316 (TOC) +1.6887 Also The average error in predicting the BOD is 22.75% The standard deviation observed is 6.776% The graph shows deviation in entire range but, equal devation is observed in the range of 12.51 to 24.54 of TOC.
How is COD and TOC calculated?
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.
Can TOC be higher 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 COD and TOC?
Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are the traditional tools often utilised. BOD and COD measure the oxygen-depleting effects of waste contaminants. The exception to this standard is the measurement of Total Organic Carbon (TOC), which directly measures inorganic and organic carbon.
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.
How do you calculate water TOC?
TOC is calculated by subtraction of the IC value from the TC of the sample. Another variant employs acidification of the sample to evolve carbon dioxide and measuring it as inorganic carbon (IC), then oxidizing and measuring the remaining non-purgeable organic carbon (NPOC).
What is TOC formula?
To calculate TOC, you can subtract the total amount of inorganic carbon from total carbon found. Alternatively, you can add Purgeable and Non-Purgeable Organic Carbon, or Dissolved and Non-Dissolved Organic Carbon. As sums, they look like: TOC = TC – TIC. TOC = POC + NPOC.
How is TOC measured?
TOC is universally measured by oxidizing the organic compounds present to forms which can be quantified. A variety of oxidation and detection methods are used depending on the nature and concentration of TOC being measured and the analytical requirements (e.g. speed, sensitivity).
Is TOC higher than COD?
COD testing is simple and less sensitive in lower concentrations, whereas TOC requires instrumental analysis but much more precise. Therefore, it is advisable to use TOC for following biodegradation reactions of compounds at low concentration (below COD 10-20 mg/L).
When to use TOC or BOD in wastewater treatment?
Industrial wastewater systems will more often use COD to measure the organic concentration moving through the treatment plant. In my experience, I see TOC being used much less often (rarely) than BOD or COD.
What should the BOD and TOC ratio be?
If the ratio is below about 0.3, either the waste may have some toxic components or acclimated microoorganisms may be required in its stabilization. The corresponding BOD/TOC ratio for untreated wastewater varies from 1.2 to 2.0.
Where does BOD, COD, and TOC come from?
The data in the table above, in the first three rows, showing the Influent Concentration, mg/L of BOD, COD, and TOC, comes from the following excellent wastewater reference source: Henze, Mogens, Poul Harremoes, Jes la Cour Jansen, and Eric Arvin. “Wastewater Treatment, Biological and Chemical Processes.”
What should the ratio of bod to cod be?
Typical values for the ratio of BOD/COD for untreated municipal wastewater are in the range from 0.3 to 0.8 (see in table 3).