摘要
实验研究了以钾长石水热分解的副产物沉淀硅酸钙为晶种,回收模拟污水中磷的效果。结果表明,晶种用量0.4 g/L、p H值为8、Ca/P(摩尔比)=2条件下反应2 h后,污水中剩余磷浓度为0.32 mg/L,低于我国污水综合排放一级A标准0.5 mg/L。沉淀硅酸钙重复使用60次后回收磷的效果仍然较好,回收率为79.5%以上。采用扫描电镜、红外光谱、粉晶X射线衍射等测试手段对回收产物进行的分析表明,回收磷产物以羟磷灰石形态存在,产物中P2O5含量在35%以上,达到了富磷矿的品位。沉淀硅酸钙有望成为回收磷的理想晶种材料。
With synthetic wastewater, the authors investigated phosphorus recovery effect by seeded crystalliza- tion of precipitated calcium silicate, which is a byproduct of feldspar hydrothermal decomposition. The results showed that the remaining effluent phosphorus concentration could meet the wastewater discharge standard of 0.5 mg/L under the optimized conditions of seed concentration of 0.4 g/L, pH value of 8 and Ca/P molar ratio of 2. Phosphorus recovery efficiency of 79.5 % showed that phosphorus recovery effect was still obvious after the precipitated calcium silicate was used for sixty times. The products obtained were analyzed by using powder X- ray diffraction （Xt~）, Fourier transform infrared （FTIR）, scanning electron microscopy （SEM） and energy dispersive spectrometry （EDS） techniques. The results show that the product of phosphorus recovery is hydrox- yapatite （HAP）. P205 content of more than 35 % shows that the product can meet the standard of the rich phos- phate rock and the precipitated calcium silicate is a potential and perfect seed of phosphorus recovery.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2014年第6期1151-1156,共6页
Acta Petrologica et Mineralogica
基金
中央高校基本科研业务费专项资金资助项目(2-9-2011-267)
关键词
沉淀硅酸钙
污水磷回收
羟磷灰石
晶种
precipitated calcium silicate
phosphorus recovery
hydroxyapatite
seeded crystallization
