The Evaluation of Air-stripping Recovery System for NH3-N from Swine Wastewater with Assistant of Anion Exchange Resin

Abstract

Ammonia nitrogen (NH4 +-N) for removal efficiency and mass transfer
coefficiency (KLa) could be investigated under different parameters by using the
recovery system. And the absorbability of phosphoric acid on NH4
+-N and reliability of prediction model for –ln (Ct/C0) are also evaluated. The results indicated that NH4 +-N removal efficiency in swine wastewater (SW) significantly enhances with increase of temperature, aeration frequency and rate due to greater KLa caused by decreasing dissolution of NH3 and promoting the diffusion of NH3 molecular. Therefore, the pH of SW can be adjusted by Lewatit M2 attributing to its costeffective, recyclability and friendlier on water resource. Combination cost and discharge standard of NH4 +-N in swine wastewater, under conditions of pH 8.0, 0.48 m3/h·L of continuous aeration, 45℃, NH4
+-N in swine wastewater remained at 68.9±6.65 mg/L (<80 mg/L) for 8 h treatment, reduced by 88.3%, and deceased to 28.4±2.69 mg/L for 12 h, in addition, NH4 +-N recovery rate can arrive to 85%. The prediction model of –ln (Ct/C0) obtained by multiple linear regression analysis has a good relationship with above parameters ( R2=0.912) and reliability.