酸改性泥炭对含亚甲基蓝废水的吸附净化作用

Adsorption removal of methylene blue dye wastewater from aqueous solution using acid modified peat

采用稀硝酸对泥炭进行改性处理获得酸改性泥炭,并将其用于处理亚甲基蓝废水。考察初始溶液pH、接触时间、酸改性泥炭投加量和亚甲基蓝溶液初始浓度等因素对酸改性泥炭吸附效果影响。结果表明,初始溶液pH、接触时间、酸改性泥炭投加量和亚甲基蓝溶液初始浓度对酸改性泥炭吸附性能都有一定的影响。在最佳的反应条件下(接触时间为60 min,反应温度为35℃,初始溶液pH为7.12,酸改性泥炭投加量为2 g),亚甲基蓝去除率可达90.88%,其吸附较好地符合Freundlich和Langmuir等温方程,拟合相关系数均大于0.9。通过热力学计算发现,ΔG<0、ΔS>0,表明该吸附反应是自发的、吸热反应。且该吸附过程符合准二级动力学方程(R2=0.98)。

Peat modified by dilute nitric acid was utilized as adsorbent to remove methylene blue( MB) from aqueous solution. Batch experiments were conducted to study the effects of pH,contact time,the dosage of acidmodified peat and the initial concentration of MB on MB adsorption. The results showed that,the removal rate of MB was affected by pH,the adsorption time,the dosage of acid-modified peat and the initial concentration of MB. When the adsorption time was 60 min,pH was 7. 12,dosage of acid-modified peat was 2 g and the temperature was 35℃,the removal rate of MB was about 90. 88%. The adsorption process can be described by Freundlich isotherms( R2> 0. 9) and Langmuir isotherms( R2> 0. 9). Thermodynamic analysis finds that when ΔG < 0and ΔS > 0,the adsorption is spontaneous and endothermic process. And it follows a pseudo-second-order kinetic model( R2= 0. 98).