谢水波,冯敏,杨金辉,刘金香,吴宇琦,周谦.腐殖酸改性针铁矿对铀U（Ⅵ）的吸附性能及机理研究[J].环境科学学报,2014,34(9):2271-2278
腐殖酸改性针铁矿对铀U（Ⅵ）的吸附性能及机理研究
- Adsorption of U(Ⅵ) by humic acid-modified goethite and its mechanism
- 基金项目：国家自然科学基金（No.11175081）；湖南省科技计划重点项目（No.2011SK2015）；湖南省高校创新平台项目（No.13K085，13K086）；湖南省自然科学基金项目（No.13JJ3078）
- 谢水波
- 1. 南华大学污染控制与资源化技术湖南省高校重点实验室, 衡阳 421001;2. 南华大学铀矿冶生物技术国防重点学科实验室, 衡阳 421001
- 冯敏
- 1. 南华大学污染控制与资源化技术湖南省高校重点实验室, 衡阳 421001
- 杨金辉
- 1. 南华大学污染控制与资源化技术湖南省高校重点实验室, 衡阳 421001
- 刘金香
- 1. 南华大学污染控制与资源化技术湖南省高校重点实验室, 衡阳 421001
- 吴宇琦
- 1. 南华大学污染控制与资源化技术湖南省高校重点实验室, 衡阳 421001
- 周谦
- 1. 南华大学污染控制与资源化技术湖南省高校重点实验室, 衡阳 421001
- 摘要：通过人工合成的方法制得腐殖酸改性针铁矿（HA-α-FeOOH），考察了吸附时间、吸附剂用量、U（Ⅵ）初始浓度和pH值等因素对吸附U（Ⅵ）过程的影响.同时，利用傅里叶红外光谱（FTIR）、扫描电镜（SEM）和X射线能谱（EDS）分析了其对U（Ⅵ）的吸附机理.试验结果表明，在25 ℃、pH为4的条件下，腐殖酸改性针铁矿作用4 h对5 mg·L-1的含铀废水的去除率几乎达到100%.Freundlich等温吸附模型、准二级动力学模型对吸附过程的拟合效果较好，主要吸附模式为多层吸附；改性针铁矿对U（Ⅵ）的吸附是自发的吸热反应.SEM-EDS和FⅡR分析结果表明，改性针铁矿吸附U（Ⅵ）的机理主要表现为内层络合作用及离子交换，与U（Ⅵ）作用的基团主要是羟基、酚羟基和羧基.
- Abstract：The goethite modified with humic acid (HA-α-FeOOH) was developed as an artificial absorbent for the removal of uranium (Ⅵ) ions from uranium-contained wastewater. To investigate the effects of experimental parameters on adsorption behavior, a batch of experiments were performed by changing solution pH, HA-α-FeOOH dosage, initial concentration of U(Ⅵ) ions and contact time. The adsorption characteristics of U(Ⅵ) by HA-α-FeOOH were analyzed by FT-IR, SEM and EDX. It is shown that the removal rate of 5 mg·L-1 U(Ⅵ) wastewater by HA-α-FeOOH almost reaches 100% under the condition of pH 4, 25 ℃ and contact time for 4 hours. The experimental data fitted well with Freundlich isotherm model, indicating that the adsorption was multilayer adsorption model. The adsorption process could be described by pseudo-second-order kinetic model. Thermodynamic parameters such as Gibbs free energy change, enthalpy change and entropy change were calculated, and the results showed that the adsorption of U(Ⅵ) onto HA-α-FeOOH was feasible, spontaneous and endothermic in nature. FTIR and SEM-EDS results showed that the adsorption mainly involves internal complexation and ion exchange, and the main binding sites with U(Ⅵ) are hydroxy, phenolic hydroxyl and carboxyl.
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