In industrial production, the problem of high-concentration treatment of ammonia nitrogen wastewater is becoming increasingly prominent, especially for chemical, pharmaceutical and fertilizer industries, ammonia nitrogen wastewater has become an environmental problem that cannot be ignored. In the production and processing process of these industries, not only directly discharge ammonia nitrogen pollutants, but also may use ammonia nitrogen as a chemical raw material, which further increases the difficulty of ammonia nitrogen wastewater treatment.
To solve this problem, companies have adopted a variety of wastewater treatment methods.
First of all, physicochemical treatment technology is one of the important means, which includes adsorption method, chemical precipitation method, blow-off method and ion exchange method. Each of these methods has its own characteristics and is suitable for different types of ammonia nitrogen wastewater treatment.
For example, the adsorption method uses an adsorbent to remove ammonia nitrogen from wastewater, and the chemical precipitation method uses a chemical precipitant to form a precipitate of ammonia nitrogen, thereby achieving solid-liquid separation.
The blowing method blows ammonia nitrogen out of wastewater by adjusting the pH and using gas blowing. Although the ion exchange method is difficult to apply in high-concentration ammonia nitrogen wastewater, it is still adopted by some enterprises due to its efficient removal ability.
However, these physicochemical treatment methods have certain limitations in practical application. For example, ion exchange methods are costly, complex to operate, and further processing of the regenerated solution is a challenge. As a result, companies often need to consider factors such as cost, efficiency, and sustainability to choose the most appropriate treatment method.
For example, a pharmaceutical company emits ammonia nitrogen concentrations of more than 5000mg/L, which is a typical problem.
In order to meet the emission standards, the company uses a combination of two-stage blow-off and biological treatment technology. First, ammonia nitrogen is blown out of wastewater by blowing, and then residual ammonia nitrogen and other contaminants are further removed using biological treatment technology. The process of blowing off involves gas entering the wastewater, adjusting the pH value to convert ammonia nitrogen into molecular ammonia, and using gas to blow out the ammonia nitrogen to effectively reduce the ammonia nitrogen content.
The blow-off effect is affected by a variety of factors, such as pH value, water temperature, gas-liquid ratio, etc. Changes in these factors will affect the removal efficiency of ammonia nitrogen. Therefore, in practice, enterprises need to precisely control these parameters to ensure the effectiveness of the treatment.
Although the blow-off method can effectively remove high concentrations of ammonia nitrogen, the treated wastewater still contains a certain amount of ammonia nitrogen.
This is where biotreatment technology comes into play. Biological treatment mainly relies on two processes: nitrification and denitrification. Under aerobic conditions, the nitrification reaction oxidizes ammonia nitrogen to nitrate nitrogen and nitrite nitrogen; Under anoxic conditions, denitrification reduces nitrate and nitrite nitrogen to nitrogen, thereby achieving the final removal of ammonia nitrogen.
From the above cases, it can be seen that the treatment of high-concentration ammonia nitrogen wastewater requires not only physicochemical means, but also the support of biological denitrification technology.
This combined treatment technology not only ensures the effectiveness of ammonia nitrogen wastewater treatment, but also improves economy and reduces operating costs. In addition, some companies have also tried to use chemical precipitation, but this method is not accepted by all companies due to the secondary pollution it may produce and the need for regular replacement of chemical precipitants.
In short, the treatment of high-concentration ammonia nitrogen wastewater is a complex process, which requires enterprises to choose the appropriate treatment method according to their own situation, and comprehensively consider the treatment effect, cost and environmental impact to achieve sustainable wastewater treatment.