改性及纳米二氧化锰负载硅藻土对苯酚废水的吸附应用研究

发布时间：2018-08-01 13:01

【摘要】：论文以十二烷基三甲基溴化铵(DTAB)为改性剂对酸洗活化后的硅藻土进行改性；以乙酸锰和柠檬酸为原料,采用溶胶-凝胶法分别制备了纳米Mn02和纳米Mn02负载的硅藻土。分别以改性硅藻土、纳米Mn02和纳米Mn02负载的硅藻土为吸附剂,以初始浓度为100mg·L-1的模拟苯酚废水中苯酚的去除率为主要考察指标,通过单因素条件实验、正交实验,分别考察并确定了改性硅藻土、纳米Mn02及纳米Mn02负载的硅藻土吸附处理模拟苯酚废水的较优化吸附工艺条件,并确定了其吸附热力学模型。实验工作得出的主要结论如下：(1)以模拟苯酚废水中苯酚的去除率为考察指标,通过单因素条件实验、正交实验考察并确定了改性硅藻土吸附处理模拟苯酚废水的较优化吸附工艺条件为：吸附温度20℃,吸附时间2h,体系pH值7,改性硅藻土用量2g·L-1。此条件下改性硅藻土对苯酚的去除率可达69.6%。(2)以模拟苯酚废水中苯酚的去除率为考察指标,通过单因素条件实验、正交实验考察并确定了纳米Mn02吸附处理模拟苯酚废水的较优化吸附工艺条件为：吸附温度20℃,吸附时间60min,体系pH值3,纳米Mn02用量0.45g·L-1。此条件下纳米MnO2对苯酚的去除率可达76.03%。(3)以苯酚去除率为考察指标,通过单因素条件实验、正交实验考察并确定了纳米MnO2负载的硅藻土吸附处理模拟苯酚废水的较优化吸附工艺条件为：吸附温度20℃,吸附时间100min,体系pH值2,纳米Mn02负载的硅藻土用量0.7g·L-1。此条件下纳米Mn02负载的硅藻土对苯酚的去除率可达86.5%。(4)吸附热力学研究结果显示：酸洗活化硅藻土和改性硅藻土对苯酚的吸附等温线符合Freundlich吸附模型；纳米Mn02和纳米Mn02负载的硅藻土对苯酚的吸附等温线符合Langmuir吸附模型。酸洗硅藻土、改性硅藻土、纳米Mn02和纳米Mn02负载的硅藻土对苯酚的饱和吸附量分别为12.15mg·g-1、26.1mg·g-1、 161.8123mg·g-1、207.0393mg·g-1。
[Abstract]:In this paper, dodecyl trimethylammonium bromide (DTAB) was used as modifier to modify diatomite after acid washing, and nanometer Mn02 supported diatomite were prepared by sol-gel method with manganese acetate and citric acid as raw materials. The modified diatomite, nanometer Mn02 and nanometer Mn02 loaded diatomite were used as adsorbents, and the removal rate of phenol in simulated phenol wastewater with initial concentration of 100mg L-1 was used as the main index. The optimum adsorption conditions of modified diatomite, nanometer Mn02 and nanometer Mn02 loaded diatomite for the treatment of simulated phenol wastewater were investigated and determined, and its adsorption thermodynamic model was determined. The main conclusions of the experiment are as follows: (1) the removal rate of phenol in simulated phenol wastewater is taken as the index of investigation. The optimum adsorption conditions for adsorption of simulated phenol wastewater by modified diatomite were investigated and determined by orthogonal experiment: adsorption temperature 20 鈩，

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