University of Rio Grande do Sul, School of Engineering, Department of Chemical Engineering, Ramiro Barcelos Street, 2777, Porto Alegre, RS, Postcode 90035-007, Brazil.
University of Rio Grande do Sul, School of Engineering, Department of Chemical Engineering, Ramiro Barcelos Street, 2777, Porto Alegre, RS, Postcode 90035-007, Brazil.
Sci Total Environ. 2021 May 1;767:144229. doi: 10.1016/j.scitotenv.2020.144229. Epub 2020 Dec 24.
Caffeine is an emerging pollutant and is considered the most representative pollutant of the Pharmaceutical Active due to its high consumption by the general population. It can be used to track pollution caused by humans. Different technologies have been employed to remove the caffeine from aqueous media, however the adsorption has been preferred due to its simplicity, high removal efficiency, operational and implementation facility and low cost. This paper provides a systematic review of the published peer-reviewed literature concerned with caffeine removal by the adsorption process. The Scopus and ScienceDirect databases were used to identify relevant articles researches on caffeine removal. Many authors have studied caffeine's adsorption equilibrium in aqueous media, different conditions, and different adsorbents. This paper aims to uncover the overall trend of adsorbent used, kinetic and thermodynamic studies. The impact of pH, temperature, adsorbent dosage and competitive effect were presented and analyzed. It was observed that the adsorption capacities ranged between 10 and 1000 mg g, according to the nature and properties of the adsorbent. The pseudo-second order (kinetic model) and the Langmuir isotherm model showed the best adjustment of the experimental data from caffeine adsorption in most studies. The mechanistic understanding of adsorption and the development of new adsorbents are still a matter of future research, as well as the use of other kinetic models based on statistical factors and the thermodynamic studies should be considered.
咖啡因是一种新兴污染物，由于其在普通人群中的高消耗，被认为是药物活性物质中最具代表性的污染物。它可用于追踪人为污染。已经采用了不同的技术来从水介质中去除咖啡因，但由于其简单性、高去除效率、操作和实施方便以及低成本，吸附法更为可取。本文对有关通过吸附过程去除咖啡因的已发表同行评议文献进行了系统综述。使用 Scopus 和 ScienceDirect 数据库来识别有关咖啡因去除的研究文章。许多作者已经研究了咖啡因在水介质中的吸附平衡、不同条件和不同吸附剂。本文旨在揭示所用吸附剂、动力学和热力学研究的总体趋势。介绍并分析了 pH 值、温度、吸附剂用量和竞争效应的影响。根据吸附剂的性质和特性，观察到吸附容量在 10 到 1000mg/g 之间。大多数研究表明，伪二阶（动力学模型）和朗缪尔等温线模型对咖啡因吸附的实验数据具有最佳的调整。对吸附机理的理解和新型吸附剂的开发仍然是未来研究的课题，此外，还应考虑基于统计因素的其他动力学模型和热力学研究。
