Abstract
Water treatment processes are designed to ensure that any pollutant’s adverse effects on
the environment are reduced to the minimum allowable discharge limit. Water-literate individuals
ought to effectively and constantly think about novel hydrologic concepts to improve the quality
and sufficiency of water. Socio-hydrological issues remain the main source of water pollution
and insufficiency in society. Therefore, effective water management and treatment require societal
understanding. The complexity of water issues requires equipping STEM education students with
the necessary knowledge to acquire water solution reasoning skills. However, STEM students
need meaningful challenges with everyday connections to capture their interest to apply intuitive
understanding in project-based learning. Water-related issues such as high turbidity are ubiquitous
problems facing communities. This study specifically explored how project-based learning can be
harnessed to enhance STEM students’ critical thinking skills using water treatment activities. The
water treatment activity involved the development of novel products using agricultural wastes for
efficient water treatment. The social issues associated with agricultural wastes, especially orange and
banana peels in the environment, are too obvious to be overlooked; hence, they were chosen as base
materials to develop water treatment products. The study adopted an action research design and
involved 12 purposively selected third-year Bachelor of Science students majoring in Chemistry at a
South African university. The students were divided into two groups consisting of six participants.
The researchers implemented team teaching and invoked students’ knowledge of Earth Science,
Physics, Chemistry, and Technology to develop and implement laboratory experimental activities
and class-based lesson plans. The empirical investigation was underpinned by the Five Steps of
Project-Based Learning as the underlying theoretical framework. The chemistry of the processed peels
such as particle size and functional groups provided insight into the mechanism responsible for water
turbidity reduction. Laboratory experimental results revealed that the turbidity reduction obtained
from the use of processed banana peels was higher than the processed orange peels coagulant.
However, the performance of both coagulants in turbidity reduction complied with the South African
National Standard (SANS241) for drinking water quality