Why the wastewater COD and wastewater BOD is often used in the waste water analysis of these two pollution indicators?

Source: http://www.cngzet.com release date: 2015-10-23

-----------------------------------------------------------------------------------------------------

There are many organic substances in wastewater, which contain more than ten kinds, dozens of species, and even hundreds of organic substances.

Inter - and - consuming drugs. Can you use only one pollution indicator to represent all the organic matter in the waste water and the number of them? Environmental scientists have found that all of the organic substances have two common characteristics:

One is that they are at least two hydrocarbons; the is that the vast majority of organic matter can be chemically oxidized or oxidized by microorganisms, and their carbon and hydrogen are formed with oxygen to form nontoxic, harmless carbon dioxide and water. Organic matter in waste water

Whether in the chemical oxidation process or in the biological oxidation process to oxygen consumption and more organic matter in wastewater, the consumption of oxygen is more, between the two is proportional relationship. Environmental science worker

The amount of oxygen consumed by chemical oxidation of waste water by chemical reagent is known as chemical oxygen demand, that is, COD, and the amount of oxygen consumed by microbial oxidation is called the biological oxygen demand, that is, BOD. Because COD and BOD can be integrated

It is widely used in wastewater analysis and environmental engineering to reflect the quantity of organic matter in wastewater.

In fact, wastewater COD is not only express in the water organic matter, it also said water with redox properties of inorganic substances, such as sulfide, ferrous ion, sodium and chloride ion and other. For example,

If the ferrous ion in the iron carbon pool is not completely removed in the neutralization tank, the effluent COD may exceed the standard due to the presence of ferrous ion.