Department of Chemistry, Anna University, University College of Engineering - Dindigul, Reddiyarchatram, Dindigul - 624 622, Tamilnadu, India.
Department of Chemistry, Bharathiar University Arts and Science College-Modakkurichi, Erode - 638 104, Tamilnadu, India.
Int J Biol Macromol. 2019 Jul 1;132:1068-1078. doi: 10.1016/j.ijbiomac.2019.03.232. Epub 2019 Mar 30.
Recently, nanomaterials based adsorbents play a prominent role in the removal of toxic ions from aqueous solution. Hence in the present study, nano-graphene oxide (n-GO) fabricated hydrotalcite (n-GO@HT) composite was prepared by hydrothermal method for chromium removal. To improve the mechanical strength and chromium removal capacity, GO@HT composite was reinforced with chitosan (CS) to form hybrid composite namely n-GO@HTCS biocomposite. The synthesized biocomposite was characterized using various instrumental techniques like FTIR, SEM, TEM and EDAX with mapping analysis. To get the maximum chromium retention, the various sorption experiments like agitation time, dosage, pH, competing ions and temperature were optimized. The sorption capacity (SC) of n-GO@HTCS biocomposite was found to be 42.64 mg/g within 50 min. The obtained equilibrium data was explained with Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherms wherein the chromium sorption process was best fitted with Langmuir isotherm. The thermodynamic results prove that the chromium sorption of n-GO@HTCS biocomposite was endothermic and spontaneous. The chromium sorbed n-GO@HTCS biocomposite could be easily regenerated with 0.1 M NaOH. The synthesized n-GO@HTCS biocomposite was also utilized in the field conditions.
最近，基于纳米材料的吸附剂在从水溶液中去除有毒离子方面发挥了重要作用。因此，在本研究中，通过水热法制备了纳米氧化石墨烯（n-GO）负载水滑石（n-GO@HT）复合材料，用于去除铬。为了提高机械强度和铬去除能力，将 GO@HT 复合材料与壳聚糖（CS）复合，形成了混合复合材料，即 n-GO@HTCS 生物复合材料。通过各种仪器技术，如傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和能谱分析（EDAX）及其映射分析对合成的生物复合材料进行了表征。为了获得最大的铬保留量，优化了各种吸附实验，如搅拌时间、用量、pH 值、竞争离子和温度。n-GO@HTCS 生物复合材料的吸附容量（SC）在 50 分钟内达到 42.64mg/g。所得平衡数据通过 Freundlich、Langmuir 和 Dubinin-Radushkevich（D-R）等温线进行解释，其中铬的吸附过程最符合 Langmuir 等温线。热力学结果证明，n-GO@HTCS 生物复合材料对铬的吸附是吸热和自发的。用 0.1 M NaOH 可轻松再生吸附铬的 n-GO@HTCS 生物复合材料。还在现场条件下使用了合成的 n-GO@HTCS 生物复合材料。
