Educational workshop on green chemistry for undergraduate studentsApplication of eco-scale to analytical methods

Resumo

An educational workshop is proposed for undergraduate students in chemistry to consciousness-raising about their environmental responsibilities as future chemists. Since 1990s, green or sustainable chemistry has been implemented mainly in research [1]. However, the green chemistry principles are particularly relevant in industry and education, since they are focused on reduction/removal of reagents and dangerous residues, decreasing the energy consumption in chemistry processes and methods. In fact, UNESCO stablished the Decade of Education in Sustainable Development during the period 2005-2014. Since pedagogy on green chemistry can be the most effective way to awareness-raising to future scientific, teaching and professional community; this matter should be taken into consideration in the curricula of undergraduate students. Green chemistry teaching can be a challenge due to the complexity of sustainability factors involved, as well as socio-economic considerations [2]. In this sense, different metrics that evaluate the greenness of a chemical process can be used to conduct different activities and develop values and attitudes among students. Specifically, it is proposed the use of analytical eco-scale, developed by Galuszka et al [3]. In order to apply the eco-scale, the didactic methodology of workshop was used to seek the active participation of students. The planning followed included an introduction to green chemistry, the establishment of agreed objectives with the students, group activities for case studies, presentation of activities results, evaluation and conclusions. In particular, students evaluated some analytical methods from the point of view of green chemistry, applying the eco-scale. This tool awards penalty points according to type and volume of reagents, required instrumentation, used energy and generated residues. The reached value on the eco-scale is calculated as 100 minus the sum of the individual penalty points. Then analytical methods can be classified as excellent (> 75 points), acceptable (75-50) and inadequate (<50). This type of workshops makes the students understand and be aware of green chemistry when they perform laboratory practices, in relation for example with the amount of reagents used or the generation of residues. Additionally, undergraduate students work with recently published articles that especially motivate them. This application helps students to be critical with the laboratory practice, assessing the importance of their work in order to avoid environmental pollution or overspend of reagents or energy. The proposed activities were highly appreciated by the students, because they can learn themselves how to use metrics to assess the greenness of chemical processes. At the same time, it increases their motivation to study subjects related with chemistry and environment.