Department of Public Works Engineering, Faculty of Engineering, Mansoura University, Mansoura, 35516, Egypt E-mail:
Water Sci Technol. 2019 Nov;80(9):1643-1653. doi: 10.2166/wst.2019.410.
In this study, the removal of phosphate (PO ) from wastewater using glauconite was investigated. Glauconite was characterized by N adsorption-desorption isotherm, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, and Fourier transform infrared (FTIR) spectroscopy. The effects of contact time, pH, initial phosphate concentrations, adsorbent dose, and temperature were investigated by batch experiments. The isotherms, kinetics and thermodynamics for phosphate removal were studied. The results showed that glauconite had a rough surface and abundant pores. The determined Brunauer-Emmett-Teller (BET) surface area was 55 m/g with a pore radius of 1.99 nm and the pore volume was 0.032 cm/g. FTIR analysis revealed that the abundance of various functional groups on the surface of glauconite may play an important role for the adsorption process. The optimum pH was 11 with complete removal of phosphate in a short time (nearly 1 min). The experimental data fitted very well with the Langmuir isotherm (R = 0.999) with a maximum adsorption capacity of 32.26 mg/g at 50 °C. Adsorption kinetic data were best fitted with the pseudo-second-order kinetic model (R = 0.999). Thermodynamic study confirmed the spontaneous, endothermic and irreversible adsorption process. Therefore, glauconite is a promising natural low-cost adsorbent for phosphate removal from wastewater.
本研究考察了海绿石去除废水中磷酸盐（PO ）的效果。通过氮气吸附-脱附等温线、扫描电子显微镜（SEM）、能谱分析（EDX）和傅里叶变换红外光谱（FTIR）对海绿石进行了表征。通过批量实验考察了接触时间、pH 值、初始磷酸盐浓度、吸附剂用量和温度对磷酸盐去除的影响。研究了磷酸盐去除的等温线、动力学和热力学。结果表明，海绿石表面粗糙，孔隙丰富。BET 表面积为 55 m/g，孔径为 1.99nm，孔体积为 0.032cm/g。FTIR 分析表明，海绿石表面各种官能团的丰富程度可能对吸附过程起重要作用。最佳 pH 值为 11，在短时间内（近 1 分钟）即可完全去除磷酸盐。实验数据与 Langmuir 等温线拟合非常好（R = 0.999），在 50°C 时最大吸附容量为 32.26mg/g。吸附动力学数据与准二级动力学模型拟合最好（R = 0.999）。热力学研究证实了吸附过程是自发的、吸热的和不可逆的。因此，海绿石是一种很有前途的天然、低成本的废水除磷吸附剂。
