甜菜粕是重金属离子螯合剂和吸附剂。研究了溶液pH值、温度、时间及初始质量浓度等条件对甜菜粕(SBP)吸附轻金属离子Ca2+和重金属离子Pb2+的性能,并体外模拟在人体肠道环境条件(pH7.0、37℃)下,研究SBP对钙和铅的吸附性能和机理。结果表明:SBP对铅的螯合大于对钙的吸附;溶液pH值为7.0时吸附效果最佳;Ca2+、Pb2+分别在30、60min内达吸附平衡。在pH7.0和37℃的生理条件下,两种离子的吸附动力学过程均符合Lagergre方程二级吸附模型,SBP对Ca2+的等温吸附平衡与Langmuir方程拟合度高,属单分子层吸附,而SBP对Pb2+的等温吸附平衡与Langmuir方程拟合度不如Ca2+高。
Sugar beet pulp is ion chelating agent and adsorbent. The adsorption properties of the light metal ions of Ca2+ and heavy metal ions of Pb2+ by the sugar beet pulp(SBP) were studied under various pH values,adsorption temperature, reaction time and initial concentration of metal ions. Absorption characteristics and mechanisms of Ca2+ and Pb2+ on the SBP under the human intestinal environmental conditions in vitro simulation (pH7.0,37℃) were studied. The experimental results indicated that the chelating capacity of Pb2+ was much higher than that of Ca2+. The adsorption capacities of metal ions reached an optimum at pH7.0. The time to reach the adsorption equilibrium of Ca2+ and Pb2+ was 30,60 rain, respectively. Additionally, under the physiological conditions (pH7. 0, 37℃), the adsorption kinetics characteristics could be well described using the presudosecond-order kinetic model. Isothermal adsorption equilibrium of SBP on Ca2+ had higher fitting degree with the Langmuir equation and it was a monolayer adsorption behavior by SBP. However,isothermal adsorption equilibrium of SBP on Pb2+ had lower fitting degree than Ca2+ with the Langmuir equation.