The Recovery of the Nitrogen and Phosphorus from Anaerobically Digested Effluent of Piggery Wastewater by White Paper Sludge Application

FENG Wen-qian1,LI Wen-wei2,WANG De-han1*,LI Dong3,SUN Yong-ming3(1.Department of Environment Science & Engineering,College of Resources and Environment,South China Agricultural University,Guangzhou 510642,China;2.Solid Waste Management Station,Environment Protection Bureau of Huizhou,Huizhou 516001,China;3.Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China)

white paper sludge;piggery wastewater;anaerobically digested effluent;recovery of nitrogen and phosphorus

The MAP precipitation process was used to recover nitrogen and phosphorus from anaerobically digested effluent of piggery wastewater.For the recovery process,white paper sludge(WPS) was used to adjust the pH values,what's more,the pH value of the effluent and the dissolution of the WPS increased by aeration.The effects on the nitrogen and phosphorus recovery efficiency by different WPS dosage and aeration time were studied,and the variation laws of pH values,COD concentration,PO3-4-P concentration,NH3-N concentration,Mg2+ concentration and Ca2+ concentration in aerating were all measured.The experimental results showed when the dosage of WPS was 8 g·L-1,and the aeration time was 120 min,the recovery efficiencies of PO3-4-P and NH3-N were 98% and 59%,respectively,as well as the removal efficiencies of COD was 45%,and the effluent concentrations of PO3-4-P and NH3-N were 0.98 mg·L-1 and 60.66 mg·L-1,respectively,those in which were lower than the standards of Discharge Standard of Pollutants for Livestock and Poultry Breeding(GB 18596—2001).However,without WPS application,when the aeration time was 120 min,the recovery efficiencies of PO3-4-P and NH3-N were only 66% and 41%,respectively,which were not meeting the standards.Therefore,it was important to recover the nitrogen and phosphorus from anaerobically digested effluent of piggery wastewater with WPS application.