磷酸条件下甘蔗渣基水热炭对Cr(Ⅵ)的吸附

Adsorption of Cr(Ⅵ) from Wastewater Using Bagasse Base Hydrothermal Carbon under Phosphoric Acid Condition

文章研究了在190℃下,磷酸条件下的甘蔗渣基水热炭对废水中Cr(Ⅵ)的吸附效果,并用了SEM、FTIR、BET等现代技术对炭化前后的甘蔗进行了表征,表征结果显示,炭化后的甘蔗渣为糅杂的层状结构,且层上有大量的孔隙,使得比表面积大大增加,水热炭化后改变了甘蔗渣原本的化学结构,新增了官能团,使吸附效果提高。实验结果表明,Cr(Ⅵ)初始浓度为50 mg/L的废水样,反应温度为35℃,炭化甘蔗渣投加量为0.6 g(即12 g/L),pH为2.0,吸附时间为120 min时,Cr(Ⅵ)去除率为95.3%,最大Cr(Ⅵ)吸附量为5.171 mg/g,吸附热力学结果显示,Langmuir等温吸附模型能更好地拟合反应吸附过程。吸附动力学结果表明,该吸附过程遵循拟二级动力学方程。

The adsorption of Cr(Ⅵ) on wastewater by phosphoric acid bagasse under hydrothermal conditions at 190 ℃ was studied. Sugarcane was characterized by SEM, FTIR and BET before and after the carbonization. The results showed that the carbonized bagasse was a mixed lamellar structure with a large number of pores on the layer, which increased the specific surface area significantly. After the hydrothermal carbonization, the original chemical structure of the bagasse was changed. Functional groups were added to make the adsorption, and the effect is improved. The experimental results showed that when the initial concentration of Cr(Ⅵ) was 50 mg/L, the reaction temperature was 35 ℃, the dosage of carbonized bagasse was 0.6 g(12 g/L), the pH was 2.0 and the adsorption time was 120 min, the removal rate of Cr(Ⅵ) was 95.3% and the maximum adsorption capacity of Cr(Ⅵ) was 5.171 mg/g. The adsorption thermodynamics results showed that the Langmuir isothermal adsorption model could better reflect the adsorption process. Adsorption kinetics results show that the adsorption process follows the pseudo-second-order kinetic equation.