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为探究铬污染的治理方法,选择园艺作物辣椒的秸秆作为吸附剂对Cr(Ⅵ)进行静态吸附实验研究,考察了吸附温度、吸附时间、溶液pH及铬溶液初始浓度对吸附过程的影响,并通过热动力学等研究探索了吸附过程的吸附机理,并结合扫描电镜-能谱分析对辣椒秸秆吸附水溶液Cr(Ⅵ)前后进行表征,结果发现溶液pH对Cr(Ⅵ)的吸附有较大的影响,在低pH值具有较高的铬吸附容量,且吸附剂的吸附容量随着吸附温度、吸附时间及初始浓度的增加而增加。在吸附剂用量12.5 g/L,初始溶液浓度160 mg/L,pH值为2.0,吸附温度40℃的条件下吸附750 min,辣椒秸秆对铬的吸附量达12.1 mg/g。热动力学研究表明整个吸附过程符合准二级动力学模型及Langmuir等温线模型,吸附是一种自发吸热熵增的过程。
In order to explore the treatment of chromium pollution, the adsorption of Cr (Ⅵ) on the adsorption of Cr (Ⅵ) was studied by using the straw of horticultural crop pepper as adsorbent. The adsorption temperature, adsorption time, initial pH of the solution and initial concentration of chromium solution were investigated. The adsorption mechanism of adsorption process was explored by thermodynamics and other methods. The adsorption of Cr (Ⅵ) on the pepper straw was characterized by scanning electron microscopy and energy dispersive spectroscopy before and after the adsorption. , And has higher chromium adsorption capacity at low pH, and the adsorption capacity of adsorbent increases with the increase of adsorption temperature, adsorption time and initial concentration. The adsorption capacity of chili straw to chrome was 12.1 mg / g when the amount of adsorbent was 12.5 g / L, the initial solution concentration was 160 mg / L, the pH value was 2.0 and the adsorption temperature was 40 ℃ for 750 min. Thermokinetic studies show that the adsorption process conforms to quasi-second-order kinetic model and Langmuir isotherm model. Adsorption is a spontaneous endothermic entropy increase process.