鸟粪石-絮凝强化工艺处理鸡粪发酵废水

以鸡粪厌氧消化液为对象,研究鸟粪石法回收氮磷的工艺条件.结果表明,反应时间30 min,搅拌转速100r.min-1,加药前调节pH值至9.0,镁氮磷物质的量比1∶1∶0.8条件下,氨氮去除率为71%,总磷去除率为59%,化学需氧量(COD)去除率为32%.反应后的上清液pH值在6～7之间,适宜投加絮凝剂进一步絮凝强化沉淀.聚合氯化铝(PAC)投加量为150mg.L-1时,氨氮、总磷、COD的总去除率为74.6%、66.8%、68.9%.有效提高了废水的可生化性.

Treatment of Chicken Manure Fermentation Wastewater by Struvite flocculation Enhancement Technology

Chicken manure fermentation wastewater contained high concentrations of ammonium, phosphate, SS(Suspend Solid) and organic pollutants, which could inhibit the subsequent biological treatment greatly, making the effluent not meet the requirement of discharging. So it needed to make a pretreatment. This paper focused on the recovery of ammonium and phosphate through struvite from anaerobic digestion wastewater of chicken waste. The optimum conditions were dicussed in the paper. The results showed that during a reaction time of 30 min and a mixed speed of 100 r.min-1,the ammonium, phosphate and COD(Chemical Oxygen Demand) were removed by 71%, 59% and 32%, respectively at initial pH 9.0 and a molar ratio of Mg:N:P=1:1:0.8. In addition, the pH of the supernatant after the reaction was between 6 and 7, so the further flocculation and sedimentation by dosing 150 mg.L-1 PAC could strengthen the pollutant removal effect. The final removal rate of ammonium, phosphate and COD of the supernatant were 74.6%, 66.8%, 68.9% respectively after the flocculation, improving the biodegradability of the effluent and recycling nitrogen and phosphorus resources effectively.