鸟粪石结晶法回收猪粪废水厌氧膜出水中磷的研究

采用厌氧膜生物反应器(AnMBR)处理猪粪废水时,发现消化液膜出水可发生自结晶沉淀反应,生成类似鸟粪石的含氮磷沉淀。试验通过控制初始pH使猪粪废水厌氧膜出水发生自结晶沉淀反应,考察了初始pH(8、9、10)对沉淀物组分及形态的影响。结果表明:初始pH为8、9、10时,磷去除率分别为30.8%、67.6%及87.7%;p H从8提高到9时,沉淀物中鸟粪石晶体的粒径变大且形态更完整;而pH为10时,颗粒较小且含钙沉淀较多;进一步分析各条件下沉淀物的晶体组分可知,初始pH为8、9时,沉淀物中晶体的主要成分为鸟粪石,而初始pH为10时,沉淀物中存在大量的含钙沉淀。因此,在该试验条件下,采用鸟粪石结晶法从该猪粪废水厌氧膜出水中回收磷的最佳初始pH为9。

STUDY ON PHOSPHOROUS RECOVERY BY STRUVITE CRYSTALLIZATION IN EFFLUENT FROM AN ANAEROBIC MEMBRANE BIOREACTOR TREATING SWINE MANURE WASTEWATER

Precipitation similar to struvite was found in the effluent of an anaerobic membrane bioreactor treating swine manure wastewater by spontaneously reaction． The test studied the effect of different initial pH ( 8，9，10) on the precipitate composition and form in order to get struvite worthy of reuse． Results showed that: Phosphorous removal rate was 30. 8%，67. 6% and 87. 7%， respectively with initial pH of 8，9 and 10; struvite crystal with bigger size and better structure was formed during pH raised from 8 to 9; but precipitation formed at initial pH 10 was small，irregular and contained much impurities; besides，struvite was the main component of the precipitation at pH 8 and 9，but lots of calcium precipitation were formed at pH 10． Therefore，the optimal initial pH was 9 in this test for phosphorous recovery as struvite from anaerobically digested swine manure wastewater．