Discussion started with kashyap ,a 9th standard student from CUBE sapekhati,collected water samples from a wetland .
@kashyap’s objective was to collect water fleas.
Later @Abhi0703 raised a question that “can we study BOD &COD using this water samples” .
These discussions are not only helped @Abhi0703 &Kashyap but also most of the Cubists are get benefited from the discussion:
KASHYAP DAS -These are two of my homelab bottles.
[23/02, 12:12 pm] Abhijeet CUBE: Kya hamlog koi easy tareeka dhund sakte hai is lake water ka BOD and COD Ghar pe find out karne ke liye?
Can we find some homelab ways to find BOD and COD of the collected water sample from Lake?
@Kashyap Sapekhati @Susanta Tanti CUBE @Arunan sir @Theertha @Aditya Joshi
How was BOD and COD measured in early days?
Analytical techniques to measure organic matter in water, such as Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), and Total Organic Carbon (TOC) are widely used. Modifications have been proposed to make them faster, more sensitive, and more environmentally friendly. The purpose of producing a review over some time is to show the changes made on the standardized methods of each of these techniques, and to highlight the relationship between them in the process of ascertaining organic matter in water
Relationship, importance, and development of analytical techniques: COD, BOD, and, TOC in water—An overview through time | Discover Applied Sciences.
[23/02, 1:28 pm] Abhijeet CUBE: This is how we did COD estimation in College:
-
Water sample from neighbouring gutter was collected.
-
We took 50ml of that sample in a flask and added 25ml of 0.25 Normal Potassium dichromate, 10ml of Conc Sulphuric Acid and kept it for 1 hr in 60°C I’m oven.
-
After it cooled we added orthophosphoric acid and lastly added 200ml D/W and added 4 drops of ferroin indicator.
-
Similarly we prepared Blank i.e. without a Sewage sample.
-
Titrated it against Ferrous Ammonium Sulphate.
[23/02, 1:30 pm] Abhijeet CUBE: For calculating COD Value:
(A-B) x N x 8000 x 1.2 / Vol. Of sample.
A= Blank
B= Sample
N= Normality of Ferrous Ammonium Sulphate
1.2= Correction Factor
Im not able to recall why why 8000 is in the formula and also I’m not sure what is this correction factor of 1.2.
Preparing for final semester BSc examination with help from 9th standard students from Sapekhati, Assam?
@Abhijeet CUBE*
Collaboration at its best, with Context2curriculum
Why prepare for examination with only with the Context of Questions Bank?*
Great initiative @Abhijeet CUBE @Kashyap Sapekhati @Susanta Tanti CUBE @Sakshi @~Akanksha Joshi @Aditya Joshi @~Dhanraj @Himanshu Joshi.
GAPS AND MISCONCEPTIONS IN UNDERSTANDING BOD &COD:
Screenshots of context to curriculum WhatsApp group:
GAPS AND MISCONCEPTIONS IN UNDERSTANDING BOD &COD:
BOD is familiar to most of us ,but i am not familiar with COD.
Following are the discussions from Context to curriculum group:
[23/02, 11:34 pm] Lahari CUBE: COD: chemical oxygen demand.
BOD: Biological oxygen demand.
BOD is the test of the amount of oxygen consumed by bacteria while decomposing organic matter under aerobic conditions. COD: COD is the test where the amount of oxygen required to oxidise total organic matter in water is tested
COD is a measure of contamination by chemicals that have a similar effect on oxygen content
★In chemical oxygen demand degradation affected by some chemical oxidising agent like potassium dichromates.★COD determination is reliable & fast the assessment of quality of water.
Where as…
BOD is measure of amount of oxygen required to degrade or breakdown the organic matter.
★BOD is a measure of biological materials that can reduce oxygen, bacteria, plant debris and many other things ★ In Biological oxygen demand, degradation of organic matter is affected by microorganisms.
★BOD doesn’t gives correct assessment of pollution and in water, because some compounds like detergents are resistance to microbial degradation and some other pollutants like cellulose get oxidised.★Toxic compounds present in polluted water may get poison.★bod determination takes too long time.
★★★So, to overcome the above BOD, COD is best because in cod water sample treated with oxidising agents (potassium dichromates).
Moina are particularly resistant to changes in the oxygen concentration and often reproduce in large quantities in water bodies strongly polluted.CIR1054/FA024: Culture Techniques of Moina : The Ideal Daphnia for Feeding Freshwater Fish Fry
[24/02, 11:14 am] Arunan sir : "Moina are particularly resistant to changes in the oxygen concentration and often reproduce in large quantities in water bodies strongly polluted with sewage. Species of Moina have been reported to play an important role in the stabilization of sewage in oxidation lagoons.
The ability to survive in oxygen-poor environments is due to their capacity to synthesize hemoglobin. Hemoglobin formation is dependent on the level of dissolved oxygen in the water. The production of hemoglobin may also be caused by high temperature and high population density."
CIR1054/FA024: Culture Techniques of Moina : The Ideal Daphnia for Feeding Freshwater Fish Fry.
[23/02, 6:08 pm] Himanshu Joshi: Analytical techniques to measure organic matter in water, such as Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), and Total Organic Carbon (TOC) are widely used.
COD is the standard analysis for measuring oxygen consumption during the decomposition of organic and oxidizing of inorganic matter, through oxidizing agents such as potassium dichromate in a short time (equivalent to hours). On the other hand, BOD5 is the standard method for determining the concentration of oxygen demand required by microorganisms to decompose organic matter, which occurs in a minimum period of 5 days. TOC is considered a potential alternative for COD and BOD, as it is faster, more precise, sensitive, and environmentally friendly.
Definitions from the same paper shared by Abhijit…
[23/02, 7:00 pm] Abhijeet CUBE: Ok. From how much I know,
BOD(Biological Oxygen Demand) ek aaisa value hai Jo hamko batata hai ki Pani me dissolved organic matter ko degrade ya breakdown karne ke liye living organisms (like microbes) ko kitna oxygen lagega.
BOD se hamko yea pata chalta hai ki Pani me dissolved organic matter ka pollution level kitna hai.
English:
Biological oxygen demand is a value that tells us how much oxygen will be required by the microbes present in the water to decompose the dissolved organic matter.
Biological oxygen demand tells us what is the pollution level of dissolved organic matter in water .
[23/02, 7:02 pm] Abhijeet CUBE: COD(Chemical Oxygen Demand) ek aaisa value hai Jo hamko yea batata hai ki Pani me dissolved Organic aur inorganic compounds ko degrade ya breakdown karne me ek particular chemical like potassium dichromate ko kitna oxygen lagega.
COD se hamko yea pata chalta hai ki Pani me total pollutants kitne hai. Organic as well as inorganic.
English:
COD (Chemical Oxygen Demand) is a value that tells us how much oxygen a particular chemical like potassium dichromate will require to degrade or breakdown organic and inorganic compounds dissolved in water.
COD lets us know how much total pollutants are present in water. Organic as well as inorganic.
Chatshaala discussions:
*Congratulations @Abhijeet CUBE for connecting Sapekhati water samples (water collected by CUBISTS in sapekhati school )to the context of Biological oxygen demand. Thanks to @Kashyap Sapekhati & other for the opportunity.
What is Biological oxygen demand ?
How can we measure that ? @Abhijeet CUBE @Smiti @~Dhanraj @Enas CUBE @Rahul CUBE @Batul Ma’am @~Ajita Banerjee @Chithra Ma’am & others .
We came across a indicator of Biological oxygen demand ,that is moina culture.
Could white-colored Moina turn red when we add more drops of milk, indicating a possible method for assessing biological oxygen demand?
Why moina turned red ? @Abhijeet CUBE @Smiti @~Dhanraj @~SMIT LOKHANDE @Sakshi @Rahul CUBE @Archita rajbhar &others.
