The purpose of the zero discharge technology of high ammonia nitrogen wastewater is to effectively treat the ammonia nitrogen and other pollutants in the wastewater, realize the resource utilization of wastewater, and avoid secondary pollution to the environment. At the heart of the technology is the removal of ammonia nitrogen from wastewater while repurposing and reusing other contaminants. Through reasonable process design and parameter control, the wastewater can reach the standard of zero discharge after treatment.
Methods for Zero Discharge Technology of High Ammonia Nitrogen Wastewater
Biological nitrification and denitrification.
Biological nitrification denitrification method is to use the nitrification and denitrification of microorganisms to convert ammonia nitrogen in wastewater into nitrogen, so as to achieve the purpose of removing ammonia nitrogen. This method needs to provide suitable nitrification and denitrification conditions, such as appropriate pH, temperature, dissolved oxygen, etc., to ensure the activity of microorganisms. Biological nitrification and denitrification have the advantages of good treatment effect and low operating cost, but it requires a long treatment time and a large reactor volume.
Breakpoint chlorination.
The breakpoint chlorination method is the oxidation of ammonia nitrogen into nitrogen by adding chlorine or sodium hypochlorite to the wastewater. The reaction conditions of this method are mild and the processing speed is fast, but it needs to add a large amount of chlorine or sodium hypochlorite, and the cost is high. In addition, the breakpoint chlorination method may produce toxic chloramines, causing secondary pollution to the environment.
Adsorption method. The adsorption method uses substances with adsorption properties (such as activated carbon, zeolite, etc.) to adsorb ammonia nitrogen in wastewater, so as to achieve the purpose of purifying water quality. The adsorption method has the advantages of good treatment effect and easy operation, but the regeneration and replacement of adsorbent requires a certain cost. In addition, the adsorption method is not effective in the treatment of low-concentration ammonia nitrogen wastewater.
The ion exchange method uses the ion exchange properties of the ion exchanger to adsorb the ammonia ions (NH4+) in the wastewater on the ion exchanger, and then displace the ammonia ions from the ion exchanger through the regenerant, so as to achieve the purpose of purifying the water quality. The ion exchange method is suitable for the treatment of high-concentration ammonia nitrogen wastewater, and the treatment effect is stable. However, the regeneration and replacement of ion exchangers requires a certain cost, and the treatment effect of low-concentration ammonia nitrogen wastewater is not good.