Azizkhani Sepehr, Mahmoudi Ebrahim, Abdullah Norhafizah, Ismail Mohd Halim Shah, Mohammad Abdul Wahab, Hussain Siti Aslina
Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang 43400, Selangor, DE, Malaysia.
Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM Bangi 43600, Selangor, DE, Malaysia.
Polymers (Basel). 2020 Aug 26;12(9):1922. doi: 10.3390/polym12091922.
Heavy metal ions have a toxic and negative influences on the environment and human health even at low concentrations and need to be removed from wastewater. Chitosan and graphene oxide are suitable nano plate adsorbents with high adsorption potential because of their π-π interaction, and they are available functional groups that interact with other elements. In this study, graphene oxide was coated with silica to enhance the hydrophilicity of the adsorbent. Subsequently, the adsorbent was functionalised by various amounts of chitosan to improve the Pb(II) removal. The adsorbent was analysed using transmission electron microscopy (TEM), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and mapping analysis techniques. An investigation of the influences of the initial concentration of Pb(II), pH and contact time were included to obtain the optimum amount of adsorption. The range of the initial Pb(II) concentration studied was from 10 to 120 mg/L. The pH factor ranged from 3 to 8 with contact time from 0 to 140 min. Freundlich, Temkin and Langmuir isotherm models were fit to the results, and a pseudo-second-order kinetic model was found to provide a good fit as well. The maximum Pb(II) removal capacity achieved was 256.41 (+/- 4%) mg/g based on Langmuir isotherms.
即使在低浓度下，重金属离子也会对环境和人类健康产生毒性和负面影响，因此需要从废水中去除。壳聚糖和氧化石墨烯因其π-π相互作用而成为具有高吸附潜力的合适纳米片状吸附剂，并且它们具有可与其他元素相互作用的官能团。在本研究中，氧化石墨烯被二氧化硅包覆以增强吸附剂的亲水性。随后，通过不同量的壳聚糖对吸附剂进行功能化处理，以提高对Pb(II)的去除效果。使用透射电子显微镜（TEM）、拉曼光谱、傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）和映射分析技术对吸附剂进行了分析。研究了Pb(II)初始浓度、pH值和接触时间的影响，以获得最佳吸附量。所研究的Pb(II)初始浓度范围为10至120 mg/L。pH值范围为3至8，接触时间为0至140分钟。将Freundlich、Temkin和Langmuir等温线模型与结果进行拟合，发现伪二级动力学模型也能很好地拟合。基于Langmuir等温线，实现的最大Pb(II)去除容量为256.41（±4%）mg/g。
