颗粒蛤蜊壳对污水中磷的吸附性能

Property of Adsorption of Phosphorus in Sewage by Granular Clamshells

选用生活中常见的厨余废弃物蛤蜊壳对污水中的磷进行吸附。分别采用linear、Langmuir、Freundlich等温吸附模型对反应吸附数据进行拟合,采用准一级动力学模型、准二级动力学模型和Elovich模型描述颗粒蛤蜊壳对水中磷的吸附动力学过程,并对反应进行热力学研究。此外,研究温度、粒径、投加量和pH等因素对蛤蜊壳吸附磷的影响。试验结果表明:Langmuir方程更适合描述颗粒蛤蜊壳的吸附行为,相关性达到显著水平;准二级动力学方程更适用于描述颗粒蛤蜊壳对水中磷的吸附动力学过程。Gibbs自由能(ΔG)<0,焓变(ΔH)>0,说明颗粒蛤蜊壳对磷的吸附是自发的吸热反应。蛤蜊壳粒径越小对磷的吸附量越大;蛤蜊壳投加量越大,磷去除率越高而吸附量越低;酸性条件利于蛤蜊壳对磷的吸附。

Clamshells, a kind of kitchen waste, were used to adsorb phosphorus in wastewater. Linear, Langnmir and Freundlich ad- sorption isotherm models were used to fit the adsorption data respectively. Pseudo first order kinetic model, quasi second order kinetic model and Elovieh model were used to describe the kinetics of phosphorus adsorption by granular clamshells, and thermodynanfies of the adsorption reaction was also studied. Moreover, impacts on phosphorus adsorption, such as temperature, granular size, dosage and pH of solution were studied. The results showed Langmuir equation was more suitable to describe the adsorption behavior of granular clamshells, of which the correlation was significant ; Quasi second order kinetics equation was more suitable to describe phosphorus adsorption kinetics. Gibbs free energy （△G） was less than zero, and enthalpy change （△H） was greater than zero, indicating that the adsorption of phosphorus by granular clamshells was a spontaneous endothermie reaction. The smaller granular size was, the better adsorption capacity of phosphorus had ; The higher dosage of granular clamshells added, the higher removal rate but lower adsorption capacity of phosphorus had; Acidic conditions was conducive to phosphorus adsorption.