添加造纸白泥对猪场废水厌氧消化液中氮磷回收的影响

以造纸废弃物白泥作为pH调节剂,利用MAP沉淀法回收厌氧消化液中的氮磷,并采用曝气的方式提高消化液pH值和造纸白泥的溶解性,研究了造纸白泥的添加量和曝气时间对厌氧消化液中氮、磷回收效果的影响,并考察了曝气过程中pH、COD、PO34--P、NH3-N、Mg2＋、Ca2＋的变化规律。结果表明造纸白泥的添加量为8g.L-1,曝气时间为120min时,PO34--P和NH3-N的回收率分别达到98和59,出水的PO34--P和NH3-N浓度分别为0.98mg.L-1和60.66mg.L-1,均达到了《畜禽养殖业污染物排放标准》（GB18596—2001）的要求,同时,COD的去除率为45;如果仅用曝气方式处理,120min后PO34--P和NH3-N的回收率仅分别为66和41,均未达到排放标准要求。可见,与仅用曝气方式处理相比,添加造纸白泥协同曝气对厌氧消化液中氮磷的回收有明显的效果。

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

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.