微孔碳@粉煤灰颗粒复合材料合成及其吸附磷应用

Synthesis of Micro-porous Carbon@Fly Ash Particle Composite Material and Its Application to Phosphorus Adsorption

制备了微孔碳@粉煤灰复合材料(简称AC@FA),利用现代分析手段对材料性能进行表征,将其应用到模拟含磷废水处理,研究不同条件下吸附特性、吸附过程动力学与等温线,并进一步运用于实际水体磷吸附。结果表明:AC@FA材料是具有不规整结构的晶体材料;比表面积大,热稳定性良好;表面具有丰富孔道结构;其对P的吸附主要来源于负载其上的多孔碳。溶液pH=3~7时,AC@FA对磷吸附效果变化不大;而pH值大于7时磷的吸附效果大幅下降,材料表面电位从正值转移为负值。AC@FA对P的吸附效果随反应温度升高而降低。准二级动力学方程适合AC@FA对P吸附过程,Langmuir吸附等温线方程更适合拟合P在AC@FA吸附。AC@FA可应用于天然水体P的吸附,AC@FA可应用于天然水体中P元素吸附,吸附后水体中P含量全部降至0.008 mg/L以下,吸附效果良好。

The microporous carbon@fly ash composite material(AC@FA for short)was prepared,and the material properties were characterized by modern analytical methods.The material was applied to the treatment of simulated phosphorus-containing wastewater,and the adsorption characteristics,adsorption process kinetics and isotherms at different conditions were investigated.Moreover,the material was further applied to the phosphorus adsorption of actual water.The results showed that,the AC@FA material was a crystalline material with an irregular structure;it had a large specific surface area and better thermal stability;the surface had a rich pore structure,and its adsorption of phosphorus mainly come from the porous carbon supported on the material.When pH value of solution ranged from 3 to 7,the adsorption effect of phosphorus on AC@FA was not changed much.While pH value was greater than 7,the adsorption effect of phosphorus decreased greatly,and the surface potential of material shifted from positive value to negative value.The adsorption effect of phosphorus on AC@FA was decreased with the increase of reaction temperature.The quasi-second-order kinetic equation was suitable for the adsorption process of phosphorus on AC@FA,and the Langmuir adsorption isotherm equation was better fit for the adsorption of phosphorus.Furthermore,AC@FA could be applied to the adsorption of phosphorus in natural water,the phosphorus content in the water body was all reduced to less than 0.008 mg/L,and it had a better adsorption effect.