Removal of Ammonia Nitrogen from Wastewater by Partial Chlorination Followed by Activated Carbon Treatment.

摘要

The objective was to investigate the feasibility of removing NH3-N from wastewater by first converting it to chloramines by partial chlorination and then removing the latter by activated carbon treatment. The first phase of the study was to evaluate the formation and stability of mono-and di-chloramines in aqueous solutions of different pH and different Cl2/NH3-N ratio. The second phase was to evaluate the quantitative interactions between activated carbon and each species of chloramines. The relative distributions of mono-and di-chloramines were dependent mainly on pH and,to a lesser degree,on the ratio of Cl2/NH3-N. In contacting with carbon,both mono-and di-chloramines disappeared quickly. The disappearance of dichloramine was generally accomplished by catalytic oxidation of its nitrogen entity to nitrogen gas. However,the loss of monochloramine was generally accompanied by about 60% reversion of its nitrogen content to ammonia. The quantity of this reversion was not reduced by 'precharging'the activated carbon with 'surface oxides'. Thus,it is concluded that the technique using partial chlorination followed by activated carbon treatment is not very effective in removing ammonia nitrogen from wastewater.