镧改性粉煤灰合成沸石的磷吸附特征研究

Phosphorus Adsorption Properties in Waste Water of La−modified Synthetic Zeolite from Coal Fly Ash

为减轻水体磷污染,以粉煤灰为原料合成沸石吸附剂,并考察镧改性处理对合成沸石的磷吸附特征的影响及机理。采用多种分析手段对改性前后的合成沸石进行理化性质表征,探究改性前后化学成分、物相组成及骨架结构等的差异。然后,借助吸附试验和理论计算,从等温吸附、吸附动力学及吸附热力学的角度,分析了镧改性合成沸石的吸附除磷机理。结果表明,经镧改性处理后,模拟废水中磷的去除率可达94.2%,较改性前提高了近65百分点。镧离子被物理负载于合成沸石的表面结构中,增强了对水中磷组分的吸附效果,且对磷的吸附属符合Langmuir和Elovich方程的自发过程。该研究为提高我国粉煤灰利用率、消除水体磷污染提供了一定理论和技术依据。

The coal fly ash sample was used to synthesize the zeolite adsorbent,and then the effect of lanthanum modification on phosphorus adsorption of the synthetic zeolite and its mechanism were investigated to help to reduce phosphorus pollution in water.The physicochemical properties of the synthetic zeolite before and after La-modification were systematically characterized by using various analytical techniques.Specifically,the differences of major components,mineral composition and structures before and after modification were explored.Furthermore,the phosphorus removal mechanism was preliminarily discussed from the perspectives of isothermal adsorption experiments,adsorption kinetics experiments and adsorption thermodynamics calculations.The results indicated that the phosphorus removal rate of the La-modified synthetic zeolite reached 94.2%in the simulated wastewater system,which was nearly 65 percentage higher than that without modification.Moreover,the lanthanum ions were physically loaded on the surface of the synthetic zeolite after modification,which enhanced the phosphorus adsorption.The phosphorus adsorption process conforms to the Langmuir adsorption isotherm model and the Elovich equation,and the adsorption happens spontaneously.The study has provided a theoretical and practical basis for promoting the utilization of coal fly ash and eliminating the phosphorus pollutants in water.