Nitrogen And Phosphorus Resource And Treatment Technology Of Source Separation Urine

Source-separated human urine has dual characteristics of resource and contaminative.The recovery of N and P from urine and the removal of contamination in it have attracted considerable attention at present.In this paper,a technological process for the efficient recovery of N and P and removal of contamination in urine was established by using vacuum thermal stripping for ammonia recovery as the core along with struvite-precipitation for P recovery and shortcut nitrification-denitrification for contaminative remove.This paper focuses on the performance of N recovery in vacuum thermal stripping,the reaction kinetics and the key parameters of the ammoniac vacuum thermal stripping,the effect of the simultaneous P recovery,and the removal effect of the contamination by the A/O-MBR.In addition,this study also research's the microbial diversity of reactor activated sludge and the organic components in effluent,and the phase composition and characterization of N and P recovery products,and comes to the conclusions as follows.(1)The effect of N recovery in urine by vacuum thermal stripping is remarkable.The ammoniac mass transfer coefficient KL,vacuum pressure of the vacuum thermal stripping and the boiling point of urine are the key parameter of ammonia recovery during vacuum thermal stripping.The optimization of time,temperature and pressure of vacuum thermal stripping are 3 h,60 C and 26.3 kPa respectively.Under this condition the recovery rate of NH4-N and KL are 81%and 16.17 + 1.73 respectively.(2)The effect of P recovery in urine by chemical precipitation is remarkable.In the process of vacuum thermal stripping,the simultaneous P recovery in urine by struvite-precipitation has no effect on the recovery of ammonia.The optimum Mg/P molar ratio was 1.29,and the recovery rate of TP was 92%under this condition.(3)The main components of N recovery products from urine are(NH4)2SO4(80.49%),followed by NH4HSO4(13.24%)and NH4NO3(6.72%).The main component of P recovery product is NH4MgPO4.(4)The shortcut nitrification-denitrification method should be adopted for the removal of contaminations in the urine after vacuum thermal stripping.The removal rates of COD and NH4+-N were 90%and 97%respectively.(5)After the treatment of the established technological process in this study,the high efficiency recovery of N and P resources and the effective removal of contaminations in source separation urine are achieved.