Introducing the 3R Program in Teaching Laboratories to Promote Sustainability Science through Miniaturization Studies on the Spectrophotometric Determination of Organic Carbon and Phosphorus in Soil

Abstract

The general assembly meeting of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in 2015 adopted the 17 Sustainable Development Goals (SDGs) aimed at achieving a better and more sustainable world by 2030. Incorporating sustainable values through a series of pedagogical strategies into university curricula to help future professionals enhance their understanding of sustainability and how they relate to it is one of the crucial steps to help achieve Sustainable Development Goals (SDGs) through education. Inspired by the principles of Green Analytical Chemistry (GAC) and the “3R” (reduce, recycle, and reuse) approach, a laboratory experiment has been developed to illustrate the basic concept of reaction miniaturization step by step. This article presents a novel experimental design consisting of 7 sessions, which includes all elements of the 3R approach. Herein, students miniaturize the conventional calorimetric determination of soil organic carbon (OC) and soil available phosphorus (P) utilizing recycled microtips and microcentrifuge tubes. Students apply their critical thinking abilities to compute and compare the waste generated, the analysis cost, and the time required for each test using the conventional approach (CA) and miniature approach (MA). They further assess the greenness of both approaches using the open-source Analytical GREEnness (AGREE) software. While students carry out these experiments, they acquire laboratory skills and reinforce their understanding of sustainability, Beer–Lambert law, how OC relates to the bioavailability of anionic nutrients such as PO43– phosphate species, and how such relationships can statistically vary based on the methods applied. Learning outcomes were assessed to evaluate the experimental design.