Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
J Colloid Interface Sci. 2015 May 1;445:303-311. doi: 10.1016/j.jcis.2014.12.056. Epub 2014 Dec 26.
Eutrophication is typically due to excessive discharge of phosphate-containing wastewater into natural waters. In this study, a novel Fe-Mg-La trimetal composite sorbent with a Fe:Mg:La molar ratio of 2:1:1 was developed through a cost-effective co-precipitation approach for phosphate removal in contaminated water. It was found that the adsorption was greatly affected by solution pH. The experimental data was better described by Langmuir isotherm model, and the maximum adsorption capacity of 415.2 mg-P/g was achieved under pH 6.0, much higher than most of sorbents previously reported. Nitrate, sulfate, bicarbonate, fluoride and humic acid widely exist in natural water, and their presences would slightly retard the adsorption of phosphate. The adsorption kinetics experiment showed that most of adsorption occurred in the first 1h and the adsorption equilibrium was achieved in 10h; the adsorption history was well described by the intraparticle diffusion model. The performance of sorbent was further confirmed by treating phosphate contaminated lake water. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicated that hydroxyl group on the sorbent surface (M-OH) played the most key role in the phosphate adsorption. The presence of sulfate group was important in the uptake as well.
富营养化通常是由于含磷酸盐废水的过度排放到自然水中造成的。在这项研究中，通过一种经济有效的共沉淀方法，开发了一种新型的 Fe-Mg-La 三元复合吸附剂，其 Fe:Mg:La 摩尔比为 2:1:1，用于去除受污染水中的磷酸盐。结果表明，吸附受溶液 pH 值的影响很大。实验数据更符合 Langmuir 等温吸附模型，在 pH 值为 6.0 时，最大吸附容量为 415.2mg-P/g，远高于以前报道的大多数吸附剂。硝酸盐、硫酸盐、碳酸氢盐、氟化物和腐殖酸广泛存在于天然水中，它们的存在会轻微抑制磷酸盐的吸附。吸附动力学实验表明，大部分吸附发生在最初的 1h 内，10h 内达到吸附平衡；吸附历程可用颗粒内扩散模型很好地描述。通过处理受磷酸盐污染的湖水进一步证实了吸附剂的性能。傅里叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）分析表明，吸附剂表面的羟基（M-OH）在磷酸盐吸附中起着最重要的作用。硫酸根的存在对摄取也很重要。
