Question: Why is the COD level of the purified water in the acidic water stripping unit so high?
Thread Content
The COD level of the purified water produced by our plant’s acidic water stripping unit has remained high recently, putting significant pressure on subsequent treatment processes. I would like to know what is causing this. Currently, the bottom temperature of the stripper is controlled at 128°C, and the top temperature is 119°C. Purified water analysis results: COD is above 2000, ammonia nitrogen is around 15 mg/L, hydrogen sulfide is around 2.3 mg/L, and oil content is around 9 mg/L.
Your ammonia, sulfides, and oil levels are not high. For over 20 years, the COD level of the water we obtain through stripping and purification has remained around 2000. However, the total amount of wastewater entering the treatment plant is usually around 600, and this value needs to be diluted with water from other systems. Or you can increase the reuse rate and reduce direct discharge to wastewater treatment plants.
A high COD value indicates a high content of Reconstituted components; in such cases, the bottom temperature of the tower can be increased slightly. I recall that in our factory it used to be 134 degrees, or we could consider adding alkali to the bottom of the tower