Zeng Le, Li Xiaomei, Liu Jindun
Alberta Research Council Inc., P.O. Box 4000, Vegreville, Alberta T9C 1TC, Canada.
Water Res. 2004 Mar;38(5):1318-26. doi: 10.1016/j.watres.2003.12.009.
This study explored the feasibility of utilizing industrial waste iron oxide tailings for phosphate removal in laboratory experiments. The experimental work emphasized on the evaluation of phosphate adsorption and desorption characteristics of the tailing material. The adsorption isotherm, kinetics, pH effect and desorption were examined in batch experiments. Five isotherm models were used for data fitting. The three-parameter equations (Redlich-Peterson and Langmuir-Freundlich) showed more applicability than the two-parameter equations (Freundlich, Langmuir and Temkin). A modified equation for calculation of the separation factor using the Langmuir-Freundlich equation constants was developed. The initial phosphate adsorption on the tailings was rapid. The adsorption kinetics can be best described by either the simple Elovich or power function equation. The phosphate adsorption on the tailings tended to decrease with an increase of pH. A phosphate desorbability of approximately 13-14% was observed, and this low desorbability likely resulted from a strong bonding between the adsorbed PO(4)(3-)and iron oxides in the tailings. Column flow-through tests using both synthetic phosphate solution and liquid hog manure confirmed the phosphate removal ability of the tailings. Due to their low cost and high capability, this type of iron oxide tailings has the potential to be utilized for cost-effective removal of phosphate from wastewater.
本研究在实验室实验中探讨了利用工业废弃氧化铁尾矿去除磷酸盐的可行性。实验工作重点在于评估尾矿材料对磷酸盐的吸附和解吸特性。在批量实验中研究了吸附等温线、动力学、pH值影响及解吸情况。使用了五种等温线模型进行数据拟合。三参数方程（雷德利希-彼得森方程和朗缪尔-弗伦德里希方程）比两参数方程（弗伦德里希方程、朗缪尔方程和坦金方程）适用性更强。利用朗缪尔-弗伦德里希方程常数开发了一个计算分离因子的修正方程。尾矿对磷酸盐的初始吸附很快。吸附动力学可用简单的埃洛维奇方程或幂函数方程来最好地描述。尾矿对磷酸盐的吸附倾向于随pH值升高而降低。观察到磷酸盐的解吸率约为13 - 14%，这种低解吸率可能是由于吸附的PO₄³⁻与尾矿中的氧化铁之间存在强键合。使用合成磷酸盐溶液和液体猪粪进行的柱式流通试验证实了尾矿去除磷酸盐的能力。由于其成本低且能力强，这类氧化铁尾矿有潜力用于经济高效地去除废水中的磷酸盐。
