A hands-on approach to teaching environmental awareness and pollutant remediation to undergraduate chemistry students

Abstract

Background : One of the unfortunate side effects of the industrial revolution has been the constant assault of the environment with various forms of pollution. Lately, this issue has taken a more critical dimension as prospects of global climate change and irreversible ecosystem damage are becoming a reality.

Purpose : College graduates (especially chemists), should therefore not only be aware of these issues but also be taught how chemistry can help reduce environmental pollution. Furthermore, the role and importance of chemistry in sustainable development and solving environmental problems needs to be highlighted.

Programme/intervention description : To this effect, we have designed a simple undergraduate experiment that is based on the green chemistry approach of using photolytic oxidation to degrade a model organic pollutant. This approach used UV light and hydrogen peroxide to produce reactive hydroxyl radicals, which subsequently break down and degrade Acridine Orange (model pollutant). The dye degradation was monitored spectrophotometrically and the apparent rate of decolouration was found to be first order. Possible radical initiated mechanisms that may be involved in this remediation experiment have been used to explain the observed dye decolouration.

Sample : To test the usefulness of this newly developed experiment, we incorporated it as a module into a second year ‘Professional skills’ chemistry course with an enrollment of six female students. Anonymous survey of the students after the completion of the module was very positive and indicated that objectives of the experiment were satisfactorily achieved.

Results : We believe this experiment not only raises students’ awareness about green chemistry and environmental issues, but also teaches them valuable experimental skills such as experimental design, data manipulation and basic kinetics. Survey of students who were taught this unit in a second year course was very positive and supported the usefulness of this unit for chemistry students.

Conclusions : In summary, we describe here an undergraduate chemistry experiments that was found to be very effective in teaching students about the hazards of environmental pollution and the role of green chemistry in solving ‘real-life’ problems, as well as chemical kinetics, data acquisition and manipulation.

Keywords:

• green chemistry
• pollutant remediation
• environmental awareness
• undergraduate laboratory
• kinetics