L-谷氨酸改性氧化石墨烯对Cu2+的吸附

采用L-谷氨酸（L-Glu）改性氧化石墨烯（GO）制备吸附剂L-Glu/GO,并进行了XRD、FTIR和SEM表征。考察了不同因素对L-Glu/GO吸附Cu²⁺的影响,并对L-Glu/GO的吸附-解吸能力进行了研究。实验结果表明：L-Glu/GO对Cu²⁺的吸附在10 min内就可达到吸附平衡;在Cu²⁺初始质量浓度为70 mg/L、初始pH为5、L-Glu/GO投加量为0.200 g/L、吸附时间为120 min、吸附温度为30 ℃的条件下,L-Glu/GO的最大吸附量可达292.460 mg/g。准二级动力学和Langmuir模型能很好地拟合此吸附过程,且显示该吸附过程可促进L-Glu/GO对Cu²⁺的吸附。热力学研究结果表明该吸附过程是一个自发的放热过程。经过5次吸附-解吸循环后,L-Glu/GO对Cu²⁺的吸附率仍在92%以上,表明该吸附剂再生性好,可重复使用。

Adsorption of Cu2+ on L-glutamic acid modified graphene oxide

Graphite oxide （GO） was modified with L-glutamic acid （L-Glu） to prepare L-Glu/GO adsorbent,and the product was characterized by XRD,FTIR and SEM. The factors affecting adsorption of Cu²⁺ on L-Glu/GO were investigated,and the adsorption-desorption performance of the L-Glu/GO was studied. The experimental results show that：The adsorption of Cu²⁺ can reach the adsorption equilibrium in 10 min;When the Cu²⁺ initial mass concentration is 70 mg/L,the initial pH is 5,the L-Glu/GO addition amount is 0.200 g/L,the adsorption time is 120 min and the temperature is 30 ℃,the maximum adsorption quantity of L-Glu/GO can reach 292.460 mg/g. Pseudo-2nd-order kinetic model and Langmuir isotherm equation fitted the adsorption process very well. In addition,the process is beneficial to the adsorption of Cu²⁺ on L-Glu/GO. Thermodynamic research results indicate that the adsorption process is a spontaneous exothermic process. By 5 cycles of adsorption-desorption,the adsorption rate of Cu²⁺ on L-Glu/GO is still over 92%,which shows that the adsorbent has good reproducibility and reusability.