2007-02-03 22:46:56 · 4 answers · asked by Yuvraj K 1 in Science & Mathematics ➔ Chemistry
ThOD (Theoretical Oxygen Demand). This is the calculated amount of oxygen required to oxidise a compound to its final oxidation products. However, there are some differences between standard methods that can influence the results obtained: for example, some calculations assume that nitrogen released from organics is generated as ammonia, whereas others allow for ammonia oxidation to nitrate. Therefore in expressing results, the calculation assumptions should always be stated.
or
Definition: The amount of oxygen that theoretically can be consumed (ThOD = theoretical oxygen demand) if the test substance is completely oxidized by microorganisms. Calculated from the test substance's chemical structure; units mg O2 per mg of test substance.
Water quality management mainly focuses on limiting oxygen demanding compounds. When oxygen drops below 2 mg/L, aquatic life is stressed
The theoretical oxygen demand of a compound can be calculated as follows:
C6H12O6 + 6O2 ------> 6CO2 + 6H2O
1 mol of glucose + 6 mol of oxygen --------> 6 mol carbon dioxide + 6 mol of water
180 g of glucose + 192 g of oxygen -----------> 264 g of carbon dioxide + 108 g of water
1.07 g of oxygen is needed for every 1 g of glucose that is biologically metabolized. This is the Theoretical Oxygen Demand (ThOD).
The theoretical oxygen demand represents the worse case scenario. The actual oxygen demand of any compound depends on the biodegradability of the compound and the specific organism metabolizing the compound. The actual oxygen demand can be measured experimentally and is called the Biochemical Oxygen Demand (BOD).
Procedure for determining the BOD:
1.Add microorganism to water with compound of interest.
2.Measure initial oxygen concentration.
3.Seal jar from atmosphere.
4.Measure oxygen concentration after 5-7 days of incubation.
The BOD is a first-order reaction .
2007-02-04 03:55:53 · answer #1 · answered by Lalitha 2 · 1⤊ 0⤋
Theoretical Oxygen Demand
2016-11-13 02:37:01 · answer #2 · answered by ? 4 · 0⤊ 0⤋
This Site Might Help You.
RE:
what is theoretical oxygen demand? how it is calculated?
2015-08-16 14:50:59 · answer #3 · answered by Anonymous · 0⤊ 0⤋
For the best answers, search on this site https://shorturl.im/pO75t
C2H5OH+ 3 O2 ----> 2 CO2 + 3 H2O Ethanol 2C = 24 6H = 6 1O = 16 Total= 46 Oxygen (3)(2)O = 96 Thus, it takes 96 g of oxygen to oxidize 46 g of ethanol to 2CO2 and 3H2O. Molarity=Mol/L= (W / MW) /L .03 M = W/46 W=1.38 g 1.38 g(96/46)= 2.88/L O_2 1.38g=30mg/L C2H5OH 2.88g=62.6 mg/L O2 1.38g=30mg/L C2H5OH 2.88g=62.6 mg/L O2 CH3COOH + 2 O2 → 2 CO2 + 2 H2O acetic acid 2C = 24 4H = 4 2O = 32 Total= 60 Thus, it takes 64 g of oxygen to oxidize 60 g of acetic acid to 2CO2 and 2H2O. Molarity=Mol/L= (W / MW) /L .2 M = W/60 W=12 g 12 g(64/60)= 12.8L O_2 12g=200mg/L 12.8g=213 mg/L O-2 one for you to do. c. 50 mg/L of C6H12O6 C6H12O6+6O2 ---->6CO2+ 6H2O
2016-04-01 02:48:13 · answer #4 · answered by Anonymous · 0⤊ 0⤋
how 0.03M value
2016-04-29 00:00:55 · answer #5 · answered by ? 1 · 0⤊ 0⤋