Volume 6, Issue 2 - Special Issue: Effective teaching tools and methods to learn about e-waste

Electrochemistry is an essential context for understanding current energetic technological processes, especially those that use batteries. On the other hand, it is one of the most neglected subjects in the classroom for reasons of associated complexity. Because of this, we have sought new methodological strategies to overcome the difficulties encountered in teaching practice. Thus, this research aims to investigate the possible contributions of a didactic sequence on the disposal of batteries from the teaching by research for the learning of electrochemistry. A qualitative methodology, a case study, applied in a high school class was adopted. The sequence consisted of six methodological steps: implementation of the problem situation; developed hypotheses; a class on electrochemistry; investigative experiment on the decomposition of batteries in aqueous solutions; systematization and communication of results. The results showed that before the application of the didactic sequence, most of the students did not know the dangers that improper disposal of batteries causes to the environment and did not understand how galvanic cells generate electrical energy from a redox reaction. After the sequence was developed, most students were able to identify and conceptualize the main electrochemical terms studied from a critical thought about this problem.

The main difference between a dry cell battery and an alkaline one is the composition of the electrolyte. In zinc–carbon batteries, dry cell, the electrolyte is a paste formed by mixing ammonium chloride and zinc chloride, whereas in alkaline batteries, the electrolyte is a concentrated aqueous solution of potassium hydroxide containing a certain amount of zinc oxide, hence the name alkaline for this battery. Therefore, the improper disposal of these materials has numerous consequences for the environment, since the potentially toxic metals present in them can be leached, infiltrating, and contaminating the soil layers, the groundwater, as well as the fauna and flora of the regions nearby. Thus, the objective is to perform studies that aim to simulate and analyze the release of potentially toxic metals present in batteries found in normal environmental conditions, through leaching tests from regular batteries (Zn–C) on fertilized soil, simulating a landfill, in addition to tests on sandy soil in order to aid the identification of possible waste release.

Over the past few years, batteries have become increasingly more common in electronic devices as part of people’s daily lives. Concerns for the environment have grown due to the improper disposal of these materials which is increasing. Batteries contain potentially toxic metals in their composition, which can lead to soil contamination due to exposure to weather conditions and rain. Concerning this matter, to prove the harm that batteries cause to aquatic environments when incorrectly discarded, students decided to carry out leaching tests that consist of using collected rainwater and a simulation of seawater, to which they added alkaline L1154 batteries connected in series and lithium batteries as well. This hands-on learning experience is intended for high school students and can be adapted to be taken in the first year of Chemistry at universities. The adaptation offers a valuable opportunity for students of different educational levels to explore the environmental impacts of batteries, provoking a deeper understanding of the chemistry involving these devices.

An e-waste outreach project was developed with two overriding goals: (1) to strengthen the partnership between the university and the local recyclable material cooperative, which has been carrying out actions aimed at supporting the work of the Cooperative, and (2) to collaborate in the expansion of environmental education activities in the process of social and economic insertion of collectors and the reduction of environmental impacts. During this process, the materials and corresponding activities related to the theoretical and practical course followed by the cooperative workers were developed by a transversal team of (under)graduate students, faculty, and staff from the Chemistry, Electric Engineering, and Public Administration areas. In addition, social media materials were created to sensibilize and engage the university community regarding effective e-waste awareness, to adhere to the voluntary drop-off point of e-waste collection, and to address the issues that can affect our environment and health if e-waste is sent to landfills. It was an example of how chemistry contributes to the Sustainable Development Goals through an outreach project.

The improper disposal of batteries has numerous consequences for the environment, since they contain potentially toxic metals that can be leached, infiltrating, and contaminating the soil layers, the groundwater, as well as the fauna and flora of nearby regions. Therefore, studies were conducted to simulate and analyze soil contamination by the release of potentially toxic metals from the incorrect disposal of alkaline batteries in the environment, in similar natural conditions, by doing leaching tests in fertilized soil resembling a landfill. Therefore, in this paper a simple experiment is proposed for sensitizing students toward the consequences of an incorrect disposal of batteries in the environment.

Lithium’s role in the global green energy transition provides an engaging context to visualize the interconnectedness of chemistry to seismic shifts taking place in society. Lithium has seen a dramatic increase in utilization, but given lithium’s current low rates of recyclability, this development is exacerbating the e-waste problem. Equally important, we posit that lithium extraction, from either brine or ore, and the associated impacts on the environment and local communities should not be so easily decoupled from the shift in human behaviors causing its demand. Presented here is a mapping activity that was trialed in professional learning workshops organized in New Zealand for secondary/high school chemistry teachers. In their mapping activity response, the teachers were able to connect typical school chemistry content (batteries, chemical processes) with environmental (planetary systems) and social, economic, and ethical considerations (useful products, unintended consequences, inequity in access to water) of the ongoing electrification of society. The teachers indicated a positive intention to utilize the activity, or one similar with a different chemical process or product, in their own classrooms. A school-ready version of the activity is provided in the supplementary information, which was revised based on feedback from the teachers attending the workshops.

Since 2004, the Italian Ministry of Education, University and Research (MIUR), the Conference of Science and Technology Headmasters, and Confindustria, have been promoting the National Plan for Scientific Degrees (PLS) aimed at supporting students in acquiring scientific skills better responding to contemporary society challenges and increasing vocations in basic sciences. This paper describes a successful experience of the University of Cagliari together with selected local secondary schools, in which the hot topic of technological waste valorization was selected to create an orientation laboratory for students towards chemistry disciplines. Specifically, students and teachers were guided into the challenging world of e-waste production and treatment through the practical activity of noble metals recovery from real waste ink-jet cartridges. A specific emphasis was placed on fundamental chemical aspects – separation and recovery of metals driven by redox processes favored by a complexing agent – as well as on the chance to play on coordination chemistry to promote a green chemistry approach. The close collaboration between school and university teachers in planning and implementing laboratory activities is the element that characterizes PLS actions and promotes the development and strengthening of relations between secondary school and university courses in science, technology, engineering, and mathematics (STEM).