β-壳聚糖/钙磷石纳米复合物的制备及其对高氟饮用水的高效净化

The Preparation of β-Chitosan/Brushite Nano-composites and Its Efficient Purification for High Fluoride Drinking Water

为实现高氟饮用水绿色、高效且安全的净化,以氯化钙、磷酸二氢钠作为前驱体,添加β-壳聚糖大分子进行调控,通过化学沉淀法制得β-壳聚糖/钙磷石纳米复合物脱氟材料。结果表明,XRD、TEM、SEM等表征所制物质为透钙磷石(Brushite)与三斜磷钙石(Monetite)的复合物。使用质量分数0.01%的β-壳聚糖作为调控剂制备的复合物脱氟性能较优:其对质量浓度为10~50 mg/L、体积为20 m L的含氟水去除率在吸附2 h后可达99.3%,由Langmuir方程拟合得吸附饱和量为123.7 mg/g。pH变化对吸附效果影响较小;Cl^-、NO_3^-、SO_4^(2-)、HCO_3^-等共存离子对吸附几乎没有影响,CO_3^(2-)的存在会产生抑制。此类纳米磷钙石吸附材料制备过程绿色简便、脱氟效率理想且健康风险较小,有望为我国高氟饮用水的净化提供新的思路。

In order to achieve the green, efficient and safe purification for high fluoride drinking water, the β-chitosan/brushite nano-composite were synthesized through chemical precipitation by using CaC12 and NaH2PO4 as the precursor and β-chitosan as the regulator. The XRD, TEM and SEM analyses indicated that this nano composite was composed of bmshite and monetite. The nano-composite prepared with 0.01% mass fraction β-Chitosan had better defluorination performance, and the removal rate ofF could achieve 99.3% after 2 h adsorption at the 20 mL fluoride containing water with 10 mg,/L to 50 mg/L mass concentration. The sorption of F. to nano-composite fitting well to the Langmuir adsorption model, and its maximum capacity was 123.7 mg/g. The change of pH had little effect on adsorption, and the co-existing ions of CI, NO3, SO42 and HCO; had almost no negative effect on F adsorption while the CO32 obviously reduced the removal rate ofF. Overall, the preparation process of this nano-composite with high defluorination efficiency and less risk is green and simple, it may provide a new idea for high fluoride drinking water purification in China.