碳羟磷灰石对废水中Zn2+的去除及机理探讨

利用废弃的鸡蛋壳为主要原料合成碳羟磷灰石(CHAP),用以去除废水中的Zn2+。分别考查了废水中Zn2+的初始浓度、CHAP的用量、pH值、温度及作用时间等因素对CHAP去除Zn2+的吸附效果的影响以优化吸附条件。结果表明,用2.5g/L的CHAP处理Zn2+的质量浓度为100mg/L的废水,40℃条件下,处理45min,Zn2+的去除率可达98.67%,最佳pH值为6～7。同时探讨了CHAP对重金属离子Zn2+的吸附机理,吸附机理研究表明,CHAP对Zn2+的主要吸附形式为离子交换吸附和表面吸附。

Discussion on Zn2+ removal from wastewater by carbonate hydroxylapatite and mechanism thereof

Carbonate hydroxylapatite(CHAP), synthesized with eggshell waste as the main material, was used to remove Zn2+ from wastewater. The effects of initial concentration of Zn2+, dosage of CHAP, pH value, temperature, reaction time and some other factors on the adsorption performance of CHAP for Zn2+ and the optimization of adsorption condition were investigated respectively. The results showed that, using 2.5 g/L of CHAP to treat wastewater whose mass concentration was 100 mg/L at 40 ℃ within 45 minutes, the removal rate of Zn2+ could reach 98.67%, and the optimal pH value was 6 - 7. The adsorption mechanism of CHAP for heavy metal ion Zn2+ was discussed at the same time, which indicated that, the main forms of Zn2+ adsorption by CHAP were ion exchange adsorption and surface adsorption.