氯化钙改性的HAP-APB@CaCO_(3)复合材料吸附性能

Study on adsorption properties of calcium chloride modified HAP-APB@CaCO_(3) composites

以石灰石粉末、磷酸氢二铵、无水氯化钙为原料,通过一步共混法制备HAP-APB@CaCO_(3)复合材料,研究复合材料对水溶液中Cu(Ⅱ)的吸附性能。利用XRD、FT-IR、SEM、BET等技术手段表征复合材料的结构和微观形貌。考察了无水氯化钙投加量、吸附时间、铜离子浓度和温度对吸附实验的影响,并借助Langmuir和Freundlich等温模型、准一级和准二级动力学模型、热力学模型对复合材料的吸附行为进行分析。结果表明,当石灰石粉末、磷酸氢二铵、无水氯化钙三者质量比为25:50:15时,复合材料对Cu(Ⅱ)的吸附性能达到最佳,在温度为30℃,Cu(Ⅱ)浓度为20 mg·L^(-1),吸附剂用量为0.01 g,pH为5.52,吸附时间为120 min时,HAP-APB@CaCO_(3)复合材料和无水氯化钙改性的HAP-APB@CaCO_(3)复合材料对Cu(Ⅱ)的吸附量分别为90.90和155.88 mg·g^(-1)。Langmuir等温线和准二级动力学可以更好地用于描述材料对Cu(Ⅱ)的吸附行为,热力学结果表明吸附材料对Cu(Ⅱ)的吸附是自发的,具有吸热性。

HAP-APB@CaCO_(3) composites were prepared by one-step blending method using limestone powder,diammonium hydrogen phosphate and anhydrous calcium chloride as raw materials to study the adsorption properties of composites on Cu(Ⅱ)in aqueous solution.The structure and microstructure of the composites were characterized by XRD,FT-IR,SEM and BET.The effects of anhydrous calcium chloride dosage,adsorption time,initial concentration of copper ion and temperature on adsorption experiments were investigated,and the Langmuir and Freundlich isotherm models,quasi-first-order and quasi-second-order kinetic models,and thermodynamic models were used to analyze the adsorption behavior of the composites.The results showed that when the mass ratio of limestone powder,diammonium phosphate and anhydrous calcium chloride was 255015,the composites had the best adsorption performance for Cu(Ⅱ).When the temperature was 30℃,the concentration of Cu(Ⅱ)was 20 mg·L^(-1),the amount of adsorbent was 0.01 g,the pH was 5.52 and the adsorption time was 120 min,the adsorption capacity of Cu(Ⅱ)on HAP-APB@CaCO_(3) and anhydrous calcium chloride modified HAP-APB@CaCO_(3) was 90.90 and 155.88 mg·L^(-1),respectively.The Langmuir isotherm and quasi-second order kinetic could be better used to describe the adsorption behavior of Cu(Ⅱ)on the materials.The thermodynamic results showed that the adsorption of Cu(Ⅱ)by the adsorbent was spontaneous and had endothermic properties.