树叶提取液制备纳米零价铁及处理含四氯化碳废水的研究

Study on the Treatment of Wastewater Containing Carbon Tetrachloride by Nanometer Zero-Valent Iron Preparated with Leaf Extracts

摘要: 利用紫叶小檗树叶提取液绿色制备的纳米零价铁。采用正交试验探究紫叶小檗树叶提取液最佳提取条件，结果表明，提取因素的重要性依次为浸提温度 > 固液比 > 浸提时间 > 乙醇浓度。最佳试验组合为浸提温度50℃、乙醇和树叶的液固比为60:1 mL/g、浸提时间为30 min、乙醇浓度为40%。采用XRD、SEM、TEM及FT-IR对紫叶小檗树叶提取液和合成的纳米零价铁进行了分析表征。以四氯化碳废水为目标吸附物，检测合成的纳米零价铁对四氯化碳的吸附还原性能。考察了初始浓度、pH和投加量对吸附还原性能的影响。结果表明：当pH和投加量一定时，初始浓度为4 mg/L时，反应时间110 min时，合成的纳米零价铁对四氯化碳的降解率最高为98.19%。当四氯化碳初始浓度和零价铁的投加量不变的条件下，pH = 6.1，反应110 min时，降解率为99.6%。当四氯化碳初始浓度和pH一定时，投加量为0.12 g/L，降解率为97.89%。该还原反应符合一级反应动力学模型。

Abstract: Nano zero-valent iron was synthesized by green methods based on purple leaf barberry leaves extract as a reducing agent and stabilizer. In order to explore the best extraction conditions of the purple leaf barberry leaves extract, we used orthogonal test. The results showed that the contributions of the factors to the polyphenols extracting could be list in descending order as follows: extraction temperature > solid-liquid ratio > extraction time > ethanol concentration. In addition, the best extracting conditions were temperature of 50˚C, ethanol and liquid solid ratio of leaves was 60:1 ml/g and leaching time was 30 min and ethanol concentration was 40%. Purple leaf barberry leaves extract and synthesis nano zero valent iron were analyzed and characterized by XRD, SEM, TEM and FTIR. Green synthesis of nano zero-valent iron adsorption performance was detected, by aiming at carbon tetrachloride adsorption. The influences of adsorption performance by the initial concentration, pH and dosing quantity were investigated. The result show that under the constant as pH and additive quantity, initial concentration of 4 mg/L, 110 min degradation reaction rate effect was 98.19%. When the initial concentration of carbon tetrachloride and zero-valent iron dosing quantity invariable condition, the optimum condition for pH is 6.1, the reaction of 110 min, the degradation rate was 99.6%. When carbon tetrachloride under the constant initial concentration and pH, the best dosing quantity is 0.12 g/L, the degradation rate is 97.89%. This reduction reaction is in line with the first order reaction kinetics model.