固定化芽孢对铽离子的吸附特性

微生物吸附法作为一种高效、廉价、环境友好的生物技术，已在稀土离子分离回收中逐渐被开发利用。实验通过固定化微生物技术，使用海藻酸钠包埋活性炭与枯草芽孢杆菌芽孢制备成固定化颗粒，处理含稀土离子的废水。对比了固定化芽孢加活性炭、固定化芽孢以及固定化活性炭对铽离子的吸附效果，并探究了不同条件对几种固定化吸附剂吸附铽离子的影响。结果表明:固定化芽孢加活性炭兼具包埋法与吸附法的优点，对铽离子的吸附效果更好; 在包炭量为1:100(活性炭质量:溶液总质量)、芽孢悬液浓度为OD₆₀₀(菌液在600 nm波长处的吸光值)=2、铽离子浓度为100 μmol/L、温度为15~25 ℃、pH=4.5~8.5的条件下吸附60 min，铽去除率可达90%以上。固定化芽孢加活性炭对铽离子的吸附更符合准一级动力学、Langmuir吸附等温线模型。 

Adsorption properties of immobilized spores on terbium ions

As an efficient, cheap and environmentally friendly biotechnology, microbial adsorption has been gradually developed and utilized in the separation and recovery of rare earth ions. Through immobilized microbial technology, sodium alginate embedded activated carbon and Bacillus subtilis spores to prepare immobilized particles to treat the wastewater containing rare earth ions. The adsorption effects of immobilized spores plus activated carbon and immobilized activated carbon on Tb(Ⅲ) were compared, and the effects of different conditions on the adsorption of Tb(Ⅲ) by several immobilized adsorbers were explored. The results show that the immobilized spores plus activated carbon have the advantages of both embedding method and adsorption method, with better adsorption effect of Tb(Ⅲ). The removal efficiency can exceed 90% under the conditions of a carbon inclusion amount of 1:100 (activated carbon mass: total mass of solution), the concentration of sporulation suspension of OD₆₀₀ (absorption value of the bacterial solution at 600 nm wavelength) = 2, Tb(Ⅲ) concentration of 100 μmol/L, temperature of 15~ 25℃, pH = 4.5~8.5 and adsorption for 60 min. The adsorption of terbium ions by immobilized spores plus activated carbon is more in line with quasi-first-order dynamics and Langmuir adsorption isotherm model.