Department of Chemical Engineering, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Department of Mining Engineering, Metallurgy and Materials, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Environ Technol. 2022 Feb;43(6):907-917. doi: 10.1080/09593330.2020.1811391. Epub 2020 Aug 27.
Emerging pollutants have received increasing attention because of their potential environmental risks. As conventional treatment processes are not able to completely remove emerging pollutants, such as drugs, for example, the adsorption process is considered a complementary treatment. However, after some time of use, the adsorbent solids used in this type of process become saturated and there may be a higher demand for replacement of these materials, resulting in a large amount of solid waste. In this context, the objective of this study was to evaluate regeneration techniques of adsorbent solid depleted with emerging tetracycline pollutant. For this, tests were performed using three regenerative methods - thermal, chemical and ultrasonic, where through them were analyzed the influence of temperature, type of solvent and sonification time, respectively. Virgin, saturated and regenerated solids were characterized by their physical structure, micro and mesopore distribution and scanning electron microscopy. For all techniques employed, the regeneration efficiency reached values above 85%. Thermal treatments at 200°C, 100% methanol solution, 100% deionized water with 60 °C heating and ultrasonic treatment at 5 and 20 minutes were chosen as the most viable methods for the study of adsorption/desorption cycles. Compared to the others, the heat treatment at 200°C remained with consistent results until the sixth cycle, presenting a regenerative capacity of 90%. Therefore, it has been selected as the most suitable regenerative agent, ensuring that CAG can be regenerated and used repeatedly in the treatment of tetracycline contaminated waters.
新兴污染物因其潜在的环境风险而受到越来越多的关注。由于传统的处理工艺无法完全去除新兴污染物，例如药物，因此吸附工艺被认为是一种补充处理方法。然而，在使用一段时间后，这种工艺中使用的吸附剂固体就会饱和，可能需要更高的更换这些材料的需求，从而产生大量的固体废物。在这种情况下，本研究的目的是评估已耗尽新兴四环素污染物的吸附剂固体的再生技术。为此，使用三种再生方法——热、化学和超声——进行了测试，分别通过它们分析了温度、溶剂类型和超声时间的影响。原始、饱和和再生的固体通过其物理结构、微孔和介孔分布以及扫描电子显微镜进行了表征。对于所采用的所有技术，再生效率均达到 85%以上。选择 200°C 的热处理、100%甲醇溶液、60°C 加热的 100%去离子水和 5 分钟和 20 分钟的超声处理作为吸附/解吸循环研究的最可行方法。与其他方法相比，200°C 的热处理在第六个循环之前一直保持一致的结果，具有 90%的再生能力。因此，它已被选为最合适的再生剂，确保 CAG 可以再生并在处理四环素污染的水中重复使用。
