带结构正电荷的镁铝氢氧化物去除水体中磷的研究

Research on the removal of excess phosphate from water samples by using Mg-Al layered double hydroxides with positive sol

以带结构正电荷的镁铝层状双金属氢氧化物(Mg-Al-LDH)溶胶为吸附剂系统研究了不同因素对磷吸附去除性能的影响,结果表明:其吸附动力学和吸附等温线分别符合准二级、Elovich速率方程和Langmuir方程,理论饱和吸附量可达55.99~60.90 mg/g。吸附过程的ΔG0为-28.78^-20.67 kJ/mol,吸附机理以静电吸引和化学吸附为主导。无机和有机阴离子会抑制磷在吸附剂上的吸附。200 mg/L的Mg-Al-LDH可以吸附90%以上的溶解性反应磷和84%的总磷,可以实现废水和富营养化水体中过量磷的吸附去除。

The effects of different factors on phosphorus adsorbing and removing capacities have been studied systematically by using a kind of Mg-Al layered double hydroxides （Mg-Al-LDH） sol having positive charge as adsorbent. The results show that both of its adsorption kinetics and adsorption isotherm accord with pseudo second order,Elovich rate equation and Langmuir equation,respectively. Its theoretical adsorption saturation quantity can reach 55.99-60.90 mg/g,adsorption process ΔG0 is -28.78--20.67 kJ/mol,and adsorption mechanism is mainly based on electro-static attraction and chemisorption. Inorganic and organic anions can restrain the adsorption of phosphorus on Mg-Al-LDH adsorbent. 200 mg/L of Mg-Al-LDH can adsorb out 90%or more of soluble reactive phosphorus and 84% of total phosphorus,realizing the adsorption of excess phosphorus from wastewater and eutrophic water samples.