煤球灰对磷的吸附特性研究

[目的]探讨煤球灰对磷的吸附特性。[方法]以餐饮业煤球燃烧后的煤球灰为试材,研究煤球灰对磷的吸附动力学过程、等温吸附以及一些因素对煤球灰吸附磷的影响。[结果]在吸附的初始阶段（0～2h）,煤球灰对磷的吸附量上升很快,此后趋于平缓;煤球灰吸附磷过程中,系统的△G0〈0,△H0〉0,说明煤球灰对磷的吸附作用是一个自发的、吸热过程;煤球灰对磷的等温吸附可用Langmuir和Temkin等温模型拟合,相关性均达极显著水平,由Langmuir等温方程计算的最大吸附量Qm为1250mg/kg;在酸性条件下,随着溶液pH值的上升,煤球灰对磷的吸附量降低,在碱性条件下,吸附量趋于平衡;低分子有机酸对磷吸附有抑制作用,对饱和磷释放有促进作用。[结论]煤球灰对磷吸附的动力学特征能很好地遵循准二级动力学模型。

Study on Adsorption Characteristics of Briquettes Ash to Phosphate

[Objective] The study aimed to discuss the adsorption characteristics of briquettes ash to phosphate.[Method] With the briquettes ash after the coalball in the catering industry were burned as the tested material,the briquettes ash on the phosphorus adsorption kinetics process,adsorption isotherm and the effects of some factors on the adsorption of briquettes ash to the phosphorus were studies.[Result] the adsorption capacity of briquettes ash to phosphorus was increased rapidly at the beginning of adsorption process(0-2 h),and then was decreased slowly.The calculation on thermodynamic parameters such as △G0 and △H0 showed that △G0 was negative and △H0 was positive during the adsorption of briquettes ash to phosphorus,indicating that the adsorption action of briquettes ash to phosphate was a spontaneous and heat absorption process.The isothermal adsorption process of briquettes ash to phosphate could be fitted by the isothermal models such as Langmium and Temkin equations and their correlation reached extremely significant level.The maximal adsorption capacity accounted by Langmium equations was 1 250 mg/kg.The adsorption capacity of briquettes ash to phosphate was decreased as pH value was increased in the condition of acidity,but the adsorption capacity trended to balance in the condition of alkalinity.The organic acid at low molecular weight could restrain the adsorption of phosphorus,but promote the release of saturated phosphorus.[Conclusion] The kinetics characteristic of adsorption of briquettes ash to phosphate could well follow the two level dynamic model.