Not known Factual Statements About chemical oxygen demand test
Not known Factual Statements About chemical oxygen demand test
Blog Article
There are lots of solutions for measuring COD, each with its benefits and drawbacks. The most typical approaches involve the dichromate strategy, the permanganate process, along with the closed reflux technique.
Insert the COD test vial in to the sample compartment ensuring that it’s effectively seated and once more press the Zero/Test key.
This benefit has become a lousy measure of your strength of organic and natural matter as oxygen also will get eaten inside the oxidation of inorganic subject for example nitrates, sulfates, and lowered metal ions, and in addition that some natural and organic elements like benzene pyridine and some other cyclic natural compounds never get oxidized by this test.
The quantity of potassium dichromate Utilized in the response is akin to the level of oxygen (O2) required to oxidise the wastewater’s natural and organic content material.
Safe the cap on to Every single COD vial. Make sure not to overtighten the cap since it could harm the closure.
Nhiều chính quyền đưa ra các quy định chặt chẽ liên quan tới nhu cầu oxy hóa học tối đa được phép trong nước thải trước khi nó được đưa trở lại môi trường.
The colorimeter or spectrophotometer will be the system that will almost certainly go through the absorbance in the samples following digestion so as to correlate it to the COD focus. Colorimeters use filters to measure mild as unique wavelengths, but spectrophotometers use a device that permits measurement across get more info a wide spectrum.
Khối lượng oxy cần thiết để oxy hóa một hợp chất hữu cơ thành dioxide cacbon, amonia và nước được thể Helloện dưới dạng tổng quát là:
Pharmaguideline is often a pharmaceutical weblog the place pharmaceutical concepts are described in quite simple and simply easy to understand language for pros and pupils. All content and SOPs are written by Ankur Choudhary.
COD means “Chemical Oxygen Demand” and is also a measure of the level of oxygen necessary to chemically oxidise natural and organic substances in water for example ammonia or nitrate, in applications for instance lakes, rivers or wastewater that have been contaminated by domestic or industrial squander.
The COD Investigation will identify the equivalent oxygen focus needed to chemically oxidise organic and natural molecules more info in h2o.
Most wastewater test effects will be described in both milligrams for each liter (mg/L) or pieces for every million (ppm). The excellent news is both of these models are equivalent and so are interchangeable!
Conversely, the BOD, despite the extremely prolonged reaction time, hasn't been capable of get replaced by any other approach either simply because some call for products (such as Organic elements) which are hard to sustain within the laboratories that could occupy them, so retaining microbial cultures to BOD biosensors is not an easy undertaking that may be as opposed with the ease that the standard procedure allows In this particular sense.
Combined with the potassium dichromate in fifty% sulfuric acid solution, pre-ready COD vials also consist of silver sulfate as a catalyst and mercuric sulfate to eradicate chloride interference. So, COD vials are regarded as dangerous squander and needs to be handled and disposed of in an accepted way.