牛骨粉为晶种的磷酸钙结晶法回收污泥发酵液中磷

Phosphorus recovery from sludge fermentation broth by cow-bone powder-seeded crystallization of calcium phosphate

以牛骨粉为晶种材料,研究不同的反应条件对磷酸钙结晶法回收污泥碱性发酵液中磷的影响。结果表明,最优反应条件为:搅拌时间2 h,pH=10.0,Ca/P摩尔比2.0,在此条件下,发酵液的浓度升高会降低磷的回收率,且成线性关系。运用扫描电子显微镜(SEM)、X-射线衍射仪(XRD)、EDX元素分析等测试方法分析晶体的组分,并与其他晶种的效果作对比,结果表明,以牛骨粉为晶种,产生的羟基磷酸钙晶体纯度更高。在实验得到的最优条件下进行流化床小试实验,可得以牛骨粉为晶种的磷酸钙结晶法磷的回收率可达89.8%,验证了以牛骨粉为晶种回收污泥发酵液中的磷在小试水平上的可行性。

Taking cow-bone powder as the seed crystal,the effects of the reaction conditions for the recovery of phosphorus from sludge fermentation broth using crystallization of calcium phosphate were investigated.Results indicated that reaction time of 2 h,pH value of 10.0,Ca/P molar ratio of 2 were the favorable conditions.Under the optimal reaction conditions,the recovery rate of phosphorus decreased linearly with the increase of fermentation broth concentration.Analytical techniques such as scanning electron microscopy（SEM）,powder X-ray diffraction（XRD） and energy dispersive X-Ray spectroscopy（EDX） were used to analyze the components of the crystals,and the result showed that the HAP produced with cow-bone powder as the seed crystal were purer than those produced with seed crystals.The lab trials of fluidized bed were established to recycle phosphorus under the optimum reaction conditions,and the recovery rate of phosphorus reached 89.8% with cow-bone powder as the seed crystal,proving that it is feasible to recovery phosphorus from sludge fermentation broth with the seed crystal in pilot-scale.