基于正交实验的凹凸棒/生物炭复合材料镉吸附性能

以凹凸棒与碱木质素为原料，采用炭化活化法制备凹凸棒/生物炭（ATP/C）复合材料，并设计正交试验对制备工艺进行优化，得出较优制备条件为:反应温度600 ℃、反应时间60 min、ATP与K₂CO₃质量比为1∶2、ATP与LG质量比为1∶2。利用XRD和SEM等技术对材料形貌以及结构等进行表征分析。详细考察投放量、初始浓度、溶液pH值以及温度等因素对ATP/C吸附Cd2+的影响，并通过吸附动力学和热力学研究ATP/C材料对Cd2+的吸附行为，结果表明:在pH值为4、投放量80 mg、溶液温度25 ℃、初始Cd2+浓度100 mg/L时，ATP/C复合材料对Cd2+的吸附容量可达到82.83 mg/g。吸附机理研究表明:吸附过程是自发进行的，符合Langmuir等温线模型和准二级动力学模型，其吸附过程由单层吸附和化学吸附共同控制。 

Study on cadmium adsorption properties of attapulgite/biochar composite material based on orthogonal experiment

The attapulgite/biochar(ATP/C in abbreviation)composites were prepared by carbonization activation method with attapulgite and alkali lignin as raw materials.The orthogonal test was also designed to optimize the preparation process,finding the optimal preparation conditions where the reaction temperature was 600℃and the reaction time 60 min.The mass ratio of ATP and K₂CO₃ was 1∶2 and that of ATP and LG 1∶2.The morphology and structure of the materials were characterized by XRD and SEM.The effects of the dosage,initial concentration,solution pH and temperature on the adsorption of cadmium by ATP/C were investigated in detail,and the adsorption behavior of ATP/C material for cadmium was studied by adsorption kinetics and thermodynamics.The results showed that the adsorption capacity of ATP/C composite for cadmium could reach 82.83 mg/g,when the optimum adsorption condition was pH 4,dosage 80 mg,solution temperature 25℃,initial Cd²⁺ concentration 100 mg/L.The adsorption mechanism research showed that adsorption process was spontaneous and conformed to langmuir isotherm model and pseudo-second-order kinetic model.The adsorption process was controlled by monolayer adsorption and chemisorption.