In water bodies, organic matter mainly comes from the discharge of domestic sewage and industrial wastewater, as well as the decomposition of animals and plants due to environmental factors. What are the hazards of excessive chemical oxygen demand (COD) in water bodies? What should we do to avoid the occurrence of “tragedies” as much as possible? Then it is necessary to be familiar with the hazards brought by COD and the control measures!

So, WhatHarms can Chemical Oxygen Demand (COD) Bring?

The higher the COD in water is, the higher the content of reductive substances (such as organic matter) in the water body will be. Reductive substances can reduce the dissolved oxygen content in the water body, thereby causing oxygen deficiency in aquatic organisms. If the situation is severe, there is a high possibility of the death of aquatic organisms, and the water quality will deteriorate and stink. In addition, there are some organic substances such as benzene and phenol that are highly toxic and directly harmful to humans, animals and aquatic organisms. Therefore, China has long regarded chemical oxygen demand (COD) as one of the important indicators for controlling water pollution.

What if the Chemical Oxygen Demand is Controlled? From the Following Four Points:

1.Control the source and prohibit the direct discharge of some waste chemical reagents, waste oil, organic waste liquid, high-concentration organic wastewater and other pollutants into the drainage system.

2.Enhance the treatment efficiency of urban domestic sewage in several ways. Collect all domestic sewage into sewage pipes and then flow it into urban sewage treatment plants for treatment before discharging or reusing. It is essential to strictly prevent sewage from being directly discharged into water bodies.

3.Control the discharge of industrial wastewater, especially in industries such as chemical engineering, pharmaceuticals, and prevention and control. Under the condition that the wastewater discharge is stably up to standard, further advanced treatment or reuse should be carried out to minimize the COD discharge as much as possible.

4.Control pollution in rural areas and agriculture well and prevent organic substances such as aquaculture wastewater and fertilizers from flowing into originally clean water sources.

Then, to know whether the COD in the water body meets the standard, an online COD analyzer is needed. Through this instrument, the chemical aerobic oxygen in the water is monitored in real time to determine whether it is qualified. Of course, COD is just one of many detection indicators. Which parameters to test specifically depends on the specific circumstances of the water sample.