羟基磷灰石的解吸再生研究:以铅离子为例

Regeneration of Hydroxyapatite: A Case Study of Lead Ion

以马弗炉450℃煅烧4 h得到的HAP为原料进行实验。研究发现,HAP在pH大于7时较稳定,HAP对Pb2+的饱和吸附量为87 mg/g。HAP在Na2EDTA中会溶解,以Na NO3作解吸剂时解吸率只有1%。以Ca(NO3)2为解吸剂,最佳解吸条件为:浓度为3 mol/L,振荡时间90 min,温度75℃,最高解吸率为36.8%。微波解吸的最佳参数为:功率600 W,时间15 min,温度25℃,最高解吸率为36%。在振荡器和微波中分别连续解吸三次,微波的效果优于振荡效果,解吸率分别为70.35%、55.75%。

Hydroxyapatite calcined at 450 ℃ for 4 hour in a muffle was used as test materials in the experiment. HAP is stable when the pH of solution higher than 7. The saturated adsorption capacity was 87 mg/g based on the analysis of Langmuir model. Na2EDTA is not suitable as desorption agent in this system since HAP was resolved in the solution. NaNO3 was also not suitable for the desorption with a desorption ratio no more than 1 %. Desorption results with Ca（NO3）2 as eluent showed that best desorption ratio was achieved at the concentration of 3 mol/L and reacting time 90 min at 75 ℃, which is 36.8 %. The desorption ratio was 36 % in microwave system with the power 600 W and 15 min. Three successive desorption experiments got better regeneration with the cumulative desorption 55.75 % in oscillator and 70.35 % in microwave oven.