碧螺春绿茶对碱性染料灿烂绿的吸附

为了探讨碧螺春茶叶用于吸附灿烂绿的可能性,研究了碧螺春绿茶吸附灿烂绿的最佳吸附条件及解吸附条件。研究结果表明,在吸附条件为当溶液起始p H值为4.1,茶叶与灿烂绿质量比为833∶1,接触时间为45 min,室温(25±1)℃时,茶叶对灿烂绿吸附率达80%,吸附量为0.96 mg/g。对Na OH、CH_3COOH和HCl3种解吸附剂的研究表明,最佳解吸附剂是Na OH,解吸1.5 h解吸率最高达93.20%。该吸附过程符合Langmuir等温吸附方程,属于单分子层吸附。吸附过程热力学参数自由能变化ΔG0,焓变ΔH=102.32 k J/mol0,熵变ΔS=0.33 k J/(mol·K)0,说明吸附过程是自发的吸热熵增过程。

Adsorption of Basic Dye Brilliant Green by Biluochun Green Tea

In order to discuss the possibility of application of Biluochun tea to the adsorption of brilliant green(BG), the optimum adsorption of BG by Biluochun green tea was studied. When the initial solution pH is 4.1, the mass ratio of BG/tea is 833:1, contact time is 45 min and the temperature is (25±1) ℃, the adsorption rate of BG by the tea reaches 80%, and the adsorption capacity is 0.96 mg/g. Studies on three desorption agents, sodium hydorxide, acetic acid, and hydrochloric acid show that sodium hydroxide is the optimal desorption agent and the highest desorption rate reaches 93.20% in 1.5 h. The adsorption process fits the Langmuir isotherm adsorption equation in a single molecular layer adsorption mode. The thermodynamic parameters of adsorption process, free energe change ΔG<0, the enthalpy change ΔH=102.32 kJ/mol>0, the entropy change ΔS=0.33 kJ/(mol·K)>0, indicate that the adsorption process is a spontaneous endothermic process with increasing entropy.