粉煤灰陶粒对水体中磷的吸附性能研究

Study on the adsorption properties of fly ash ceramsite for phosphorus in water

以粉煤灰为主要原料制成粉煤灰陶粒,研究其对低浓度含磷废水的除磷特性,考察其对磷的等温吸附和热动力学吸附过程,以及投加量、粒径和pH对吸附除磷特性的影响。结果表明,粉煤灰陶粒对磷的吸附效果可以较好地被Langmuir吸附等温模型拟合,拟合计算粉煤灰陶粒对磷的最大吸附量为0.874 mg/g。粉煤灰陶粒对磷的吸附过程可以总结为“快速吸附,缓慢平衡”,符合准一级动力学模型。吸附热力学研究表明粉煤灰陶粒对磷的吸附是一个自发的吸热过程。粉煤灰陶粒投加量为3 g时可以较好地满足除磷性能和经济成本的要求;在一定范围内适当减少粉煤灰陶粒粒径可以提高其吸附除磷性能;在pH=6.0时其吸附除磷效果最佳。

Fly ash was used as the main raw material to make fly ash ceramsite,and its phosphorus removal effect on low-concentration phosphorus-containing wastewater was studied.The adsorption isotherm and adsorption thermodynamics of its adsorption and phosphorus removal were studied,as well as the effects of dosage,particle size and pH on the adsorption and phosphorus removal characteristics.The results show that the adsorption effect of fly ash ceramsite on phosphorus can be well fitted by the Langmuir adsorption isotherm model,and the maximum phosphorus adsorption capacity of fly ash ceramsite is 0.874 mg/g.The adsorption process of phosphorus on fly ash ceramsite can be summarized as“fast adsorption,slow equilibrium”,which conforms to the pseudo-first-order kinetic model.The adsorption thermodynamics study showed that the adsorption of phosphorus on fly ash ceramsite is a spontaneous endothermic process.When the dosage of fly ash ceramsite is 3 g,it can better take into account the requirements of phosphorus removal performance and economic cost;appropriately reducing the particle size of fly ash ceramsite within a certain range can improve its adsorption and phosphorus removal capacity;when pH=6.0 the adsorption and phosphorus removal effect is the best.