前处理对猪场废水厌氧段氮磷降解影响研究

Influence to the Nitrogen and Phosphorus Degradation in Anaerobic Process with the Pretreatment of the Piggery Wastewater

猪场废水经过厌氧处理后,水中溶解性NH_4^+-N、PO_4^(3-)-P浓度升高造成后续处理负荷增大,是目前猪场废水难以达标排放的主要原因。该文用MAP沉淀法对猪场废水氮磷进行前处理后,进一步通过批式厌氧发酵实验详细地对比沉淀后尾水与原水厌氧效果,研究结果表明,在药剂量P:Mg:N摩尔比1:1:4.0和溶液pH值9.0条件下MAP沉淀后废水氮磷去除率分别达到35.7%、93.7%以上;厌氧后沉淀尾水发酵液中NH_4^+-N、PO_4^(3-)-P浓度可比原废水发酵液分别降低437、55.1 mg/L,并且COD去除率提高10.3%以上,因此MAP沉淀技术对猪场废水氮磷实施厌氧前控制具有可行性,而且显著改善厌氧处理效果。

NH4^＋-N and PO4^3--P concentrations from piggery wastewater would be increased after anaerobic process,which resulted in the load increase in further treatments and hardly satisfying the discharging standards.Using the MAP precipitation to pre-degrade NH4^＋-N and PO4^3--P concentrations of the piggery wastewater and the batch type anaerobic fermentation experiments were carried out to study the effects of the anaerobic degradation between the supernatants from MAP precipitation and raw wastewater.Results showed that NH4^＋-N,PO4^3--P concentrations were degraded to 35.7%,93.7% under the condition of P：Mg：N ratio 1：l：4.0 and pH value 9.0,and in the following anaerobic process,NH4^＋-N,PO4^3--P concentrations of the supernatants from MAP precipitation were decreased to 437,55.1 mg/L,meanwhile COD degradation was improved by 11%compared with the supernatants of the raw wastewater.Hence,MAP precipitation to pre-degrade NH4^＋-N,PO4^3--P concentrations of the piggery wastewater were benefit to the further anaerobic fermentation and significantly improved the anaerobic effects.