Study On Removal Of Ammonia Nitrogen In Piggery Wastewater By Ultrasound Stripping

Livestock wastewater is typical for high concentration of ammonia, COD and SS.Aquaculture industry which belongs to a small profit industry,can not afford the high costs of waster treatment.Nowadays,the major objective of wastewater treatment was organic compound,so COD has a more substantial reduction and the reduction of ammonia is not enough to meet the requirement. Ammonia nitrogen will be one of the binding targets of water pollutants during the 12th Five-year Plan.It is only very recently that the removal of ammonia nitrogen in Piggery Wastewater is brought into focus.Ultrasound treatment technology is a green water treatment technology. Stripping, ultrasound and ultrasonic stripping was used to treat ammonia nitrogen of piggery wastewater. This paper studied the influential factors of degradation. Results are summarized as follows:(1) The study of removing ammonia nitrogen in piggery wastewater by stripping indicated that pH value, initial ammonia nitrogen concentration, aeration rate, packing and the type of bubble exerted influence on removing ammonia nitrogen. Under the condition of initial low concentration of ammonia nitrogen, the efficiency of ammonia nitrogen removal was not high. Under the condition of initial high concentration of ammonia nitrogen, the efficiency of ammonia nitrogen removal was much better than that of low concentration. The effect of pH value on ammonia nitrogen removal was not distinct and pH was not significant change in reaction process. With the increase of aeration rate, the efficiency of removing ammonia nitrogen was increased. Packing acted a stimulus to the efficiency of removing ammonia nitrogen in a certain extent. Under the condition of the micro bubble aeration, the efficiency of ammonia nitrogen removal was much better than that of the small bubble aeration. The removal efficiency of NH3-N reached 60.99%and the remanent NH3-N concentration was 253.4mg/L which was not reach the discharge standard of pollutants for livestock and poultry breeding. (2) The study of removing ammonia nitrogen in piggery wastewater by ultrasound indicated that pH value, initial ammonia nitrogen concentration, ultrasonic power and packing exerted influence on removing ammonia nitrogen. the higher the initial ammonia nitrogen concentration, the higher the removal efficiency of NH3-N; The effect of pH value on ammonia nitrogen removal was not distinct and pH showed tendency to descend in reaction process; Ultrasonic power had a positive correlation with the efficiency of removing ammonia nitrogen; Packing acted a stimulus to the efficiency of removing ammonia nitrogen in a certain extent. Under the condition of the micro bubble aeration, the efficiency of ammonia nitrogen removal was much better than that of the small bubble aeration.The removal efficiency of NH3-N reached 45.82% and the remanent NH3-N concentration was not reach the discharge standard of pollutants for livestock and poultry breeding.(3) The study of removing ammonia nitrogen in piggery wastewater by ultrasonic stripping indicated that the effect of pH value including other factors etc. was similar to the condition of stripping or ultrasound. The removal efficiency of NH3-N reached 88.06% and the remanent NH3-N concentration was 78.4mg/L which was reach the discharge standard of pollutants for livestock and poultry breeding.(4) The removal rate of the NH3-N was just 40～60% only by stripping or ultrasound, but could reach above 80% by ultrasonic stripping. Compared with stripping or ultrasound, ultrasonic stripping was a more effective way of removing ammonia nitrogen.