工业固废基-羟基磷灰石的制备及其对Cr(Ⅵ)吸附性能研究

Preparation of Industrial Solid Waste Based HAP and Its Adsorption Performance for Cr(Ⅵ)

文章采用工业废石膏与高浓度模拟含磷废水得到前驱物钙源与磷源,通过共沉淀法合成环境友好型高效能吸附材料工业固废基-羟基磷灰石(ISW-HAP),开展模拟含Cr(Ⅵ)废水吸附试验与吸附再生实验,探究ISW-HAP材料对Cr(Ⅵ)的吸附性能。结果表明,当ISW-HAP投加量为0.15 g、Cr(Ⅵ)溶液初始浓度为100 mg/L、pH=9、吸附时间为4 h、环境温度为35℃时,ISW-HAP对Cr(Ⅵ)的吸附性能最佳,Cr(Ⅵ)去除率最高达到93.17%。材料经过6次吸附循环再生实验测试,Cr(Ⅵ)去除率仍保持在70%左右,具有良好的再生性能。通过XRD、官能团分析、SEM(EDS)分析对吸附前后的ISW-HAP进行表征,结果显示制备所得的球状的ISW-HAP颗粒排列不规则,整体呈现球霰石型结构,符合羟基磷灰石本身形貌特征,具有丰富的孔隙结构与较大的比表面积,EDS结果证明了Cr(Ⅵ)的成功吸附,XRD与FTIR表明了ISW-HAP良好的合成效果,进一步验证了ISW-HAP材料吸附过程中的稳定性以及微观结构上的稳定性。综合各表征与实验结果进行吸附机理探究,结果表明,ISW-HAP对Cr(Ⅵ)的吸附包括离子交换和表面络合、官能团强化吸附,范德华力和静电引力实现的物理吸附,以及潜在的氧化还原反应等。

Industrial waste gypsum and high concentration simulated phosphorus containing wastewater were used to prepare precursor calcium and phosphorus sources,and an environmentally friendly and efficient adsorption material-industrial solid waste based hydroxyapatite(ISW-HAP)was synthesized through co-precipitation method.Simulated adsorption and regener⁃ation experiments were coriducted on wastewater containing Cr(Ⅵ)to explore the adsorption performance of ISW-HAP mate⁃rials on Cr(Ⅵ).The experimental results show that when the dosage of ISW-HAP is 0.15 g,the initial concentration of Cr(Ⅵ)solution is 100 mg/L,pH=9,the adsorption time is 4 h,and the ambient temperature is 35℃,ISW-HAP has the best ad⁃sorption performance for Cr(Ⅵ),with the highest Cr(Ⅵ)removal rate reaching 93.17%.After 6 cycles of adsorption and regen⁃eration experiments,the Cr(Ⅵ)removal rate of the material remains around 70%,indicating good regeneration performance.The ISW-HAP before and after adsorption was characterized by XRD,functional group analysis,and SEM(EDS)analysis.The results showed that the spherical ISW-HAP particles were irregularly arranged and presented a spherical aragonite like structure,which was consistent with the morphology characteristics of hydroxyapatite itself.It had rich pore structure and a large specific surface area.The EDS results confirmed the successful adsorption of Cr(Ⅵ),and XRD and FTIR showed good synthesis effect of ISW-HAP,further verifying the stability of the ISW-HAP material during adsorption and the stability of the microstructure.Based on the comprehensive characterization and experimental results,the adsorption mechanism of Cr(Ⅵ)by ISW-HAP was investigated.The results showed that the adsorption of Cr(Ⅵ)by ISW-HAP includes ion exchange and surface complexation,functional group enhanced adsorption,physical adsorption achieved by van der Waals forces and Environmental Science&Technology electrostatic attraction,and potential redox reactions.