水合二氧化锰对Co2+的吸附行为研究

以KMnO₄为原料合成了水合二氧化锰（HMO），采用XRD、BET、TG-DTA和FT-IR对HMO进行了表征。在此基础上，研究了各实验条件对HMO吸附Co²⁺的影响，并将其用于含⁶⁰Co废水的实际处理研究。结果表明：HMO对溶液中的Co²⁺具有良好吸附能力，在pH=7、T=298 K条件下，其最大吸附量达132.98 mg/g；溶液pH值能显著影响Co²⁺在HMO上的吸附，在实验pH值范围内，吸附量随pH值增大而增加；在钴初始浓度相同的条件下，吸附量随温度升高而增加；Na⁺、K⁺、Mg²⁺、Ca²⁺、Zn²⁺、Fe³⁺等离子的存在对HMO吸附Co²⁺具有一定影响。HMO对Co²⁺的吸附过程符合准二级动力学模型（R²＞0.99），推测吸附过程中可能存在一定的化学吸附；吸附热力学行为可用Langmuir等温吸附方程进行描述（R²＞0.99），表明Co²⁺在HMO上为单分子层吸附；由吸附热力学数据ΔH=46.96 kJ/mol、ΔG=-26.09 kJ/mol可知，此吸附行为是自发进行的吸热反应。另外，在实际处理含⁶⁰Co废水的动态柱实验中，HMO对初始放射性浓度为2.78×10⁵ Bq/L的⁶⁰Co废液的去除率可达56.90%。

Adsorption of Co2+ on Hydrated Manganese Dioxide

The hydrated manganese dioxide (HMO ) was prepared by the oxidation‐reduction method with potassium permanganate as starting materials ,while the resulted HMO was characterized by XRD ,BET ,TG‐DTA and FT‐IR .In the adsorption experi‐ment ,the influences of various experimental conditions were investigated ,and HMO was also applied for the actual treatment of 60 Co wastewater .Experimental results show a good adsorption property of Co2+ on HMO ,in the condition of pH=7 and T=298 K , with a maximum adsorption capacity of 132.98 mg/g .The pH of the solution can signifi‐cantly affect Co2+ adsorbed on HMO ,and in the experimental pH range ,the adsorption capacity increases with pH .Under the same Co2+ initial concentration ,the adsorption capacity increases with temperature .Co2+ adsorption on HMO is influenced while Na+ , K+ ,M g2+ ,Ca2+ ,Zn2+ and Fe3+ coexisted in the solution .T he adsorption behavior of Co2+ on HMO is well described by pseudo‐second‐order kinetic model and Langmuir isotherm model (R2 >0.99) ,and it is indicated that the adsorption process maybe a chemical and monolayer adsorption . T he adsorption thermodynamics data of ΔH=46.96 kJ/mol andΔG= -26.09 kJ/mol show that the adsorption process is endothermic and spontaneous . In addition ,when treating wastewater containing 60Co whose initial radioactivity concen‐tration is 2.78 × 105 Bq/L in the dynamic column experiment ,the removal rate is 56.90% .