In order to study the influence of the different factor to the removal efficiency of ammonia nitrogen as well as the best craft operational factor,using polypropylene-stage-ring as purging tower fillings,orthogonal experiments were conducted to investigate the influencing factors on the removal efficiency of ammonia nitrogen.The result showed that the sequence of the degree size of effecting on ammonia nitrogen stripping efficiency,one by one in order,was: pH> air/water ratio> hydraulic load>ammonia nitroge...