改性坡缕石黏土对直接大红的吸附性能研究

Study on the Adsorption of Direct Scarlet by Modified Palygorskite Clay

用氧化铝对坡缕石黏土进行包覆改性,通过静态吸附实验研究了改性黏土吸附染料直接大红的特征。结果表明,改性坡缕石黏土对直接大红的吸附作用较原土明显提高,在吸附剂用量为2.0 g/L、振荡速度为150r/min、pH值近中性的条件下,吸附率达90%以上;吸附过程较好地符合准二级动力学模式,吸附等温线可由Langmuir方程描述,吸附焓ΔH为10.06 kJ/mol,吉布斯自由能ΔG<0,吸附是自发的吸热过程。

The adsorption properties of direct scarlet on palygorskite clay in Gansu coated with alumina were investigated through static adsorption experiments. The results indicate that the adsorption capacity of modified clay can be enhanced greatly than raw clay and adsorption rate is above 90% when the amount of adsorbent is 2.0 g/L, vibrating rate is 150 r/min and pH value is about neutral. The adsorption processes follow the pseudo-second-order equation most well and adsorption isotherms fit Langmuir equation. The adsorption enthalpy is 10.06 k J/tool and adsorption Gibbs free energy changes are negative, the adsorption process is endothermic and spontaneous.