黄芩废渣生物质炭对废水中Cr^6+吸附性能

Adsorption Properties of Scutellaria Residue Biochar on Cr^6+From Waste Water

以黄芩废渣为原料制备生物质炭,吸附废水中Cr^6+,考察pH值、吸附剂用量、吸附时间和温度对吸附效果的影响.实验表明,pH值和生物质炭用量对Cr^6+在生物质炭表面的平衡吸附量有明显影响.在pH=2.0,生物质炭用量为0.2 g/L的含Cr^6+(100 mg/L)废水中,生物质炭对Cr^6+的平衡吸附量可达215 mg/g.吸附过程符合准二级动力学模型,吸附速率受表面扩散和内扩散混合控制,生物质炭内外表面对Cr^6+吸附容量相当;同时吸附符合Langmuir等温吸附模型,属自发吸热过程.

The biochar was prepared using the scutellaria residue and was then used to absorb Cr^6+in waste water to examine the effect of pH,biochar dosage,adsorption time and temperature on the adsorption capacity.The experimental results indicated that the equilibrium adsorption capacity of the Scutellaria residue biochar on Cr^6+was dramatically affected by pH value and the biochar dosage.The equilibrium adsorption capacity of Cr^6+could reach 215 mg/g under the conditions of the biochar dosage of 0.2 g/L,Cr^6+concentration of 100mg/L and pH 2.0 in the waste water.The adsorption process could be described by the pseudo-second order kinetics model,while the rate was controlled by the surface diffusion and internal diffusion together,the capacity of internal and external surface of biochar on Cr^6+was equivalent.The absorption isotherm matches the Langmuir isotherm adsorption equation,which was a spontaneous endothermic reaction.