Study On Removal Of Ammonia From Coking-plant Wastewater By Sonolysis And Photocatalysis

It is an important task with practical value to treate ammonia nitrogen wastewater.On the basis of surveying ammonia nitrogen wastewater controlling approaches inside and outside country. Ammonia nitrogen wastewater treated by ultrasound oxidation technology and photocatalytic technology was studied systematically in this dissertation .The study showed that the technology was in these two possessions of the prominent virtues,such as simple process equipment,operation conditions controlled easily,no secondary pollution,etc.But these technologies can treat low concentration of ammonia nitrogen wastewater efficiently,they can not treat high or medium concentration of ammonia nitrogen wastewater efficiently.Sonophotocatalytic oxidation technology can maintenance the prominent virtues of these technologies and treat effiently this kind of wastewater.So it can provide new thoughts and pathways for industrialization treatment of ammonia nitrogen wastewater and will be endowed with extentsive application prospect in the ammonia nitrogen wastewater treatment,The main contents of experiment were as follows:(1) Using the ultrasound oxidation technology treating ammonia nitrogen wastewater, factors affecting ultrasound oxidation reaction were studied in details such as different modes, initial pH value, initial concentration, the reaction temperature and the frequency of ultrasound wave ,etc.(2) Analogue ammonia nitrogen wastewater was selected as ammonia nitrogen wastewater to simulate this kind of wastewater which was treated by photocatalytic oxidation using the anatase TiO₂ as photocatalyst, UV-lamp as radiation source.Factors affecting photocatalytic oxidation reaction were studied in details, such as initial concentration of wastewater, catalyst amount, initial pH value, calcinations temperature and time, etc.(3) Comparing with ultrasonic oxidation technology and photocatalytic oxidation technology, the result indicated that sonophotocatalytic oxidation technology can treat ammonia nitrogen wastewater effiently,and the enhancement was barely as much as the sonophotocatalytic oxidation technology in which the photocatalytic oxidation and ultrasonic oxidation technology were implemented simultaneously along with the whole process .It showed that there was the synergistic effect of the photocatalytic oxidation and ultrasonic oxidation technology.Major factors affecting sonophotocatalytic oxidation reaction were studied.(4) Using the US/UV/ TiO₂ methods treating ammonia nitrogen of coking wastewater, factors affecting US/UV/ TiO₂ reaction were studied in details such as initial pH value, initial concentration, catalyst amount and the frequency of ultrasound wave, etc.(5) To test the degradation efficiency of the US/UV/ TiO₂ methods on actual coking wastewater, ammonia nitrogen wastewater was degraded with the optimal conditions,in which NH₃-N reduced from 570.64mg/L to 123.77 mg/L after 4 hours,the degradation efficiency of NH₃-N was 78.31%.