海藻酸钠凝胶球对水中无机磷的吸附性能

Adsorption Performance of Alginate Gel Beads for Phosphorus in Aqueous Solution

利用一定质量分数的海藻酸钠(SA)滴入Ca2+、Fe3+等溶液中会形成规则球形的特性制备凝胶球,用于处理含磷废水。研究了不同凝胶球的除磷特性及除磷效果,并对腐殖酸与无机磷混合溶液进行吸附研究。实验结果表明,凝胶球对无机磷具有很强的吸附性能,该技术具有工艺简单、处理效率高、速度快等优点。吸附时间16h,海藻酸钠—钙—铁(Ⅲ)凝胶球对200mL(TP=50mg/L)的模拟污水去除率接近50%,海藻酸钠—铁(Ⅲ)凝胶球对磷的去除率可接近97%。海藻酸钠—钙—铁(Ⅲ)凝胶球在酸性条件下比较稳定,在碱性条件下易被分解。Langmuir型方程式可以较好地描述海藻酸钠—钙—铁(Ⅲ)凝胶球对磷的吸附行为,最大吸附量为1428.6mg/g,海藻酸钠最佳制备质量分数为2%。研究结果还表明,海藻酸钠—钙—铁(Ⅲ)凝胶球可以选择性去除与腐殖物质共存水体中的磷。

A certain concentration of sodium alginate solution will change to regular gel beads when it is instilled into Ca^2＋ or Fe^3＋ solutions. By means of this characteristic, sodium alginate can be apphed to the disposal of wastewater containing phosphorus. The phosphorus removal effects and characteristics of different gel beads were compared, and the phosphorus adsorption effect of alginate gel beads in a mixture solution of humic acid and inorganic phosphorus was also studied. Result shows that gel bead has a very strong adsorption on inorganic phosphorus. The disposal method is simple and rapid with high efficiency. The counterbalanced time is 16 hours. The removal rate of calcium-iron（ Ⅲ ） -alginate gel beads treating 200 mL （ Tp = 50 mg/L） of simulant wastewater reaches 50% , while that of the iron（ Ⅲ ） -alginate gel beads is about 97% under the same condition. Calcium-iron（ Ⅲ ）-alginate gel beads is very steady under acid condition, while it is easily decomposed under alkaline condition. Langmuir equation can well describe the phosphorus adsorption of calcium-iron （ Ⅲ ） -alginate gel beads, and the highest adsorption amount is 1 428.6 mg/g and the optimal alginate concentration is 2%. Moreover, the result also shows that calcium-iron（Ⅲ ） -alginate gel beads can selectively adsorb phosphorus when humic acid and phosphorus are simultaneous in the water.