الأكسجين الممتص حيوياً
English translation: BOD (biological oxygen demand)
| GLOSSARY ENTRY (DERIVED FROM QUESTION BELOW) | ||||||
|---|---|---|---|---|---|---|
|
| 11:34 Apr 12, 2006 |
| Arabic to English translations [PRO] Social Sciences - Environment & Ecology | |||||||
|---|---|---|---|---|---|---|---|
|
| ||||||
|  Selected response from: ahmadwadan.com Saudi Arabia Local time: 17:45 | ||||||
Grading comment
| |||||||
| Summary of answers provided | ||||
|---|---|---|---|---|
| 4 +5 | BOD (biochemical oxygen demand) |
| ||
| 4 +1 | bio-absorbable oxygen |
|
| Discussion entries: 3 | |
|---|---|
Answers
21 mins confidence: 
peer agreement (net): +5
peer agreement (net): +5BOD (biochemical oxygen demand) Explanation: Biochemical Oxygen Demand (BOD) A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater the degree of pollution. -------------------------------------------------- Note added at 22 mins (2006-04-12 11:57:11 GMT) -------------------------------------------------- Biochemical oxygen demand In ecology, biochemical (biological) oxygen demand (BOD) is an indicator for the concentration of biodegradable organic matter present in a sample of water. It can be used to infer the general quality of the water and its degree of pollution. BOD measures the rate of uptake of oxygen by micro-organisms in the sample of water at a fixed temperature and over a given period of time. To ensure that all other conditions are equal, a very small amount of micro-organism seed is added to each sample being tested. This seed is typically generated by diluting activated sludge with de-ionised water. All samples being tested in any one batch are inoculated with an equal volume of seed including the sample control of de-ionised water saturated with oxygen. The BOD in the UK is carried out by diluting the sample with de-ionised water saturated with oxygen then sealing the sample (to prevent further oxygen dissolving in), and placing it in the dark (to prevent photosynthesis and thereby the addition of oxygen). This sample is kept at 20 °C in the dark and tested for dissolved oxygen (DO) after five days. The apparent BOD for the control is subtracted from the test result to provide the corrected value. The loss of dissolved oxygen in the sample, once corrections have been made for the degree of dilution, is called the BOD5. In the UK allyl thiurea is also added at the start of the test to prevent oxidation of ammonia. Results from such tests are represented as BOT5(ATU) and referred to as Carbonaceous BOD (CBOD) in the US. Less frequently used is the Ultimate BOD (UBOD) test, in which DO is repeatedly measured by DO meter in the same specialized bottles until it has reached equilibrium. -------------------------------------------------- Note added at 2 hrs (2006-04-12 13:50:27 GMT) -------------------------------------------------- BIOLOGICAL si used too. Reference: http://www.pnic.gov.ps/arabic/environment/study/Study6.html |
| |
Grading comment
| ||