【摘要】 以模拟的厌氧消化液为处理对象,通过小试实验,考察不同初始磷浓度C P、Ca/P物质的量比、pH和温度下,碳酸根(CO2-3)对磷酸钙沉淀反应回收磷的影响;利用扫描电镜(SEM)、X射线衍射仪(XRD)和傅里叶变换红外光谱(FTIR)对沉淀产物进行表征。结果表明,高浓度的CO2-3对以磷酸钙沉淀反应去除和回收磷的效率影响较大;C P相同时,CO2-3浓度(C CO2-3)越大,P的去除率越低,低C P(20 mg/L)时尤为显著;当C CO2-3相同时,随着C P的增大,反应速率加快,P的去除率逐渐升高,但升高幅度越来越小;增大Ca/P比和pH能提高P的去除率,降低CO2-3对磷酸钙沉淀反应的抑制作用,综合考虑实际效果,应选择Ca/P比为3.33,pH为9.0作为适宜的反应条件;升高温度对降低CO2-3对磷酸钙沉淀反应的抑制作用贡献不大。在C P为60 mg/L,Ca/P比为1.67,pH为9.0,温度为20℃的条件下,当C CO2-3为0时,得到的沉淀产物主要为羟基磷灰石HAP;当C CO2-3为30 mmol/L时,得到的沉淀产物为磷酸钙和碳酸合磷灰石的混合物。更多还原

【Abstract】 The effect of carbonate( CO2-3) on the reaction of calcium phosphate precipitation at different initial phosphorus( P) concentrations,Ca / P ratios,pH values and temperatures were investigated using synthetic anaerobic digestion supernatant as treatment target at bench-scale. The precipitates were characterized by scanning electron microscope( SEM),X-ray Diffraction( XRD) and Fourier transform infrared spectrometer( FTIR). The results showed that the high concentration CO2-3 had more effect on the efficiency of phosphorus removal and recovery in the precipitated reaction of calcium phosphate. The phosphorus removal efficiency was lower when the CO2-3 concentration was higher at the same P concentration,especially at the low P concentration( 20 mg / L). The phosphorus removal efficiency was higher but increased slowly when the initial P concentration increased and the reaction rate accelerated. The removal efficiency of phosphate also increased with the increase of Ca / P ratio and pH value and decreased with the decrease of CO2-3 concentration. The optimized reaction conditions were Ca / P ratio of 3. 33 and pH value of 9. 0 when compared the whole experimental results. There was no obvious decrease of the inhibitory effect of CO2-3 on the reaction of calcium phosphate precipitation when the solution temperature increased. Moreover,most of the obtained precipitate was hydroxyapatite under the conditions of no CO2-3,C P of 60 mg / L,Ca / P of 1. 67,pH value of 9. 0 and temperature of 20℃. However,most of the obtained precipitates were the mixture of calcium phosphate and carbonate-hydroxyapatite when the CO2-3 concentration was 30 mmol / L.更多还原