Nitrogen Removal In Iron Inner Electrolysis-biological Coupling Process

Inner electrolysis device consist of iron-scrap was set inside of SBR reactor in this research. Shortcut nitrification-denitrification can be carried out by the coupling between chemical reaction and biodegradation. The experiment indicated that there is a stable and efficient nitrite accumulation through controlling the major factors as the free ammonia(FA) concentration, the pH, the temperature, the dissolved oxygen(DO) concentration and so on at normal temperature 25 ℃.Comparative experiment analysis confirmed that iron in the reactor has a significant auxo-action to nitrosation., and is a major factor is shortcut nitrification - denitrification. The study shows that the iron ion concentration has an direct influence on coupling nitrification-denitrification reaction progress. When the iron ion concentration was from 11.85mg/L to 19.5mg/L, the nitrogen removal efficiency was above 90%. pH is an important factor affecting shortcut nitrification-denitrification.in the coupling reactor. The experiment studied the increase of ammonia nitrogen and accumulation of nitrite under the condition of pH=7.5⁹.5 in the coupling process, and the range of pH was grater the traditional process as from 8.0to 9.0. Research shows that pH alteration has obvious law in shortcut nitrification - denitrification process. Some characteristic point was in the profile of pH .According to the rule of pH alteration, the automation in shortcut nitrification-denitrification reaction could be realized. The research showed that the high DO concentration as more than 4.0mg/L has a direct influence on coupling nitrification-denitrification reaction progress. From the experiment results shows, higher DO concentration accelerate corrode of iron scrap. These results indicate that the nitrogen degradation efficiency is satisfactory at normal temperature in the coupling reactor. Under the condition of 25 ℃, the average rate of nitrosation [NO₂^-/( NO₂^-+ NO₃^-)] is above 80% by increasing the concentration of influent ammonia. Finally we concluded that the study on shortcut nitrification-denitrification at normal temperature had significant practical value on the treatment of wastewater having...