The factors that affect COD treatment effect are mainly as follows:
1.Biological toxicity: If the wastewater contains high concentrations of toxic and harmful substances, such as heavy metals, high salt, cyanide, halogen elements and other inorganic chemical poisons, or phenols, polycyclic aromatic hydrocarbons, aromatic amino compounds and other organic chemical poisons, it will seriously affect the growth and reproduction of microorganisms, resulting in low biochemical degradation efficiency.
2.Wastewater biodegradability: The higher the content of substances in wastewater that cannot be degraded or utilized by microorganisms, the worse its biodegradability, resulting in a lower COD biochemical removal rate.
3.Reaction time: The oxidation reaction requires sufficient time to complete. Too short or too long a reaction time may lead to poor treatment results. The former may be due to incomplete reaction, while the latter may cause side reactions or re-reduction of organic matter.
4.Microbial activity: Microbial activity corresponds to biodegradation capacity. If the activity of microorganisms is insufficient, the COD treatment effect will also be affected.
5.Nutrition ratio: In the biological treatment process, the ratio of carbon, nitrogen and phosphorus (the ideal ratio is about 100:5:1) is crucial to the activity of microorganisms. Improper ratio will affect the growth and reproduction of microorganisms, thereby affecting the removal efficiency of COD.
6.Environmental conditions: The growth and reproduction of microorganisms and the functioning of biological enzymes require suitable environmental conditions, such as temperature, pH value, dissolved oxygen, conductivity and trace elements. Deviation from the optimal range will affect the COD treatment effect.
7.Interfering substances: If there are interfering substances that affect COD measurement in the wastewater, such as halogen elements, it will interfere with the COD measurement results and thus affect the evaluation of the treatment effect.
8.Influent water quality: If the emission sources of pollutants are not effectively controlled, industrial wastewater containing recalcitrant organic matter is more difficult to treat than domestic sewage, resulting in lower COD removal rates.
9.Treatment facility design and operation status: Improperly designed or mismatched treatment facilities (such as excessive hydraulic load) will reduce the treatment effect. In addition, the daily operation and management of the system, including sludge concentration control, aeration volume control, etc., also directly affects COD removal.
10.Equipment aging or failure: Sewage treatment equipment may age or fail after long-term operation. For example, aging of aeration equipment may lead to insufficient aeration, which will affect the COD removal effect.
In view of the above factors that affect the COD treatment effect, we can pre-treat the water by digestion method before testing the water quality. At the same time, for the influencing factors in the COD determination process, such as water sample properties, oxidant type and concentration, pH and temperature, etc., corresponding elimination methods are also needed to ensure the accuracy of the determination results.Erun Environmental Protection produces professional COD water quality testing and analyzing instruments, equipped with special digestion instruments, which can quickly and accurately process COD and detect its content. If you need detailed water quality testing instrument prices, you can directly consult the website's online customer service.
