花状Ni-Fe-LDHs的制备及其循环利用吸附氟离子的性能研究

Study on the preparation of flower-like Ni-Fe-LDHs and their recycling performance for fluoride ion adsorption

以氯化镍、氯化铁为原料,尿素作为沉淀剂,采用均相沉淀技术制备了Ni-Fe-复合金属氢氧化物(Ni-Fe-LDHs)吸附剂。采用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电镜(SEM)、能谱(EDS)等方法对Ni-Fe-LDHs的成分和结构进行了分析,并分析了Ni-Fe-LDHs吸附氟离子的性能。结果表明:Ni-Fe-LDHs呈花状形貌,该花状形貌边缘具有典型的LDHs材料层状结构。Ni-Fe-LDHs对氟去除率为98.2%。吸附氟离子后的Ni-Fe-LDHs材料经过400℃焙烧及碱处理后可进行再生并可重复利用。随着循环次数的增加,Ni-Fe-LDHs除氟率虽然降低,但该材料多次循环后,除氟率逐渐趋于稳定,重复利用12次后,其除氟率仍能达80%以上,具有重要的循环利用价值。

Ni-Fe-complex metal hydroxide(Ni-Fe-LDHs) materials were synthesized by homogeneous precipitation technology with NiCl·6 HO,FeCl·6 HO as raw materials and urea as precipitant.The Ni-Fe-LDHs were characterized by XRD,FT-IR,SEM and EDS.The results shown that the synthesized materials had flower-like morphology with the typical layered structure of hydrotalcite structure.The Ni-Fe-LDHs had high fluorine removal rate, and its fluorine removal rate was 98.2%.The Ni-Fe-LDHs could be used repeatly via calcined recovery method.With the number of cycles increased, the defluorination efficiency of Ni-Fe-LDHs was decreased.After 12 cycles, the defluorination rate of Ni-Fe-LDHs tended to be stable and it still keeps 80 %,and the material shown important recycling value.