Baigorria Estefanía, Carvalho Lucas Bragança, Alves Pinto Luciana Matos, Fraceto Leonardo Fernandes
Institute of Science and Technology, São Paulo State University, Sorocaba, Brazil.
Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Mar del Plata (UNMdP), Buenos Aires, Argentina.
Front Chem. 2024 Aug 29;12:1450089. doi: 10.3389/fchem.2024.1450089. eCollection 2024.
Overusing and misusing pesticides, including paraquat (PQ), have led to numerous environmental contamination complications. PQ is an emerging bio-accumulative contaminant that is present in environmental aqueous matrices. Adsorption techniques are part of a set of technologies applied in ecological remediation, known for their high effectiveness in removing aqueous PQ. A study of the PQ adsorption capacity of three cyclodextrin-silica nanocomposites (α-CDSi, β-CDSi, and γ-CDSi) from contaminated waters is presented in this paper.
The cyclodextrin-silica nanocomposites were synthesized via an esterification reaction between the inorganic matrix and cyclodextrins (CDs) (α, β, and γ) and were characterized physicochemically by spectroscopic, thermal, and surface methods. Their PQ removal performance from contaminated aqueous media was studied under different experimental conditions.
The results showed a fast adsorptive response in removal treatment studies over time. Adsorption capacities of 87.22, 57.17, and 77.27 mg.g were found for α-CDSi, β-CDSi, and γ-CDSi, respectively, at only 30 min of treatment. Thermodynamic studies indicated spontaneous and exothermic adsorption processes. The removal assays responded mainly to physisorption mechanisms with contributions from chemisorption mechanisms. Spectroscopic assays showed a strong interaction of PQ with the adsorbents used. Innovative CDSi nanocomposites have proven to be highly efficient in applying aqueous PQ remediation, thus proving to be sustainable adsorbents of contaminants of emerging importance worldwide.
过度使用和滥用包括百草枯（PQ）在内的农药已导致众多环境污染并发症。百草枯是一种新出现的生物累积性污染物，存在于环境水体基质中。吸附技术是生态修复中应用的一系列技术的一部分，以其在去除水体中百草枯方面的高效性而闻名。本文介绍了对三种环糊精 - 二氧化硅纳米复合材料（α - CDSi、β - CDSi和γ - CDSi）从受污染水体中吸附百草枯能力的研究。
通过无机基质与环糊精（α、β和γ）之间的酯化反应合成环糊精 - 二氧化硅纳米复合材料，并通过光谱、热分析和表面方法对其进行物理化学表征。在不同实验条件下研究了它们从受污染水介质中去除百草枯的性能。
结果表明，在去除处理研究中，随着时间的推移有快速的吸附响应。在仅30分钟的处理时间下，α - CDSi、β - CDSi和γ - CDSi的吸附容量分别为87.22、57.17和77.27 mg·g。热力学研究表明吸附过程是自发的且放热的。去除试验主要响应物理吸附机制，同时也有化学吸附机制的贡献。光谱分析表明百草枯与所用吸附剂之间有强烈的相互作用。创新的CDSi纳米复合材料已被证明在应用水体中百草枯修复方面非常高效，因此被证明是全球范围内新出现的重要污染物的可持续吸附剂。
