Sathvika T, Kumar Saraswathi Akhil Raj, Rajesh Vidya, Rajesh N
Department of Chemistry, Birla Institute of Technology and Science, Pilani-Hyderabad Campus Hyderabad 500 078 India
Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-Hyderabad Campus Hyderabad 500 078 India.
RSC Adv. 2019 Sep 10;9(49):28478-28489. doi: 10.1039/c9ra05528b. eCollection 2019 Sep 9.
Chromium in its hexavalent oxidation state is carcinogenic and wastewater from the electroplating industry is one of the principal sources of pollution. To reduce this toxicity and pave way towards environmental safety, a combination of environmental microbiology and chemistry is quite efficient for developing biosorbents to sequester chromium from waste water. Immobilization of in sodium montmorillonite provides a conducive environment to capture hexavalent chromium. Various characterization techniques such as FTIR, XPS and SEM-EDAX were performed and batch parameters such as pH variation, adsorbent dosage, concentration of metal ion and temperature were optimized. Pseudo second order kinetics coupled with a higher regression coefficient for Freundlich isotherm and a Langmuir adsorption capacity of 22.22 mg g was achieved for the adsorption process. The adsorption was enhanced by the charge interactions between the protonated clay- surface and Cr(vi) ions in acidic medium. The biosorbent was stable and easily regenerated using NaOH. Preliminary column studies were performed to test the efficiency of the developed biosorbent at higher volumes on a laboratory scale.
六价氧化态的铬具有致癌性，电镀行业废水是主要污染源之一。为降低这种毒性并为环境安全铺平道路，环境微生物学与化学相结合对于开发从废水中螯合铬的生物吸附剂非常有效。将[具体物质]固定在钠蒙脱石中为捕获六价铬提供了有利环境。进行了诸如傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）和扫描电子显微镜-能谱分析（SEM-EDAX）等各种表征技术，并优化了诸如pH变化、吸附剂用量、金属离子浓度和温度等批次参数。吸附过程实现了伪二级动力学，弗伦德利希等温线具有较高的回归系数，朗缪尔吸附容量为22.22 mg/g。在酸性介质中，质子化粘土表面与Cr(Ⅵ)离子之间的电荷相互作用增强了吸附。该生物吸附剂稳定，使用氢氧化钠易于再生。进行了初步的柱实验，以在实验室规模上测试所开发的生物吸附剂在更大体积下的效率。
