KAS Students Use New Science Skills to Test Water
Robert McCarl High School Science HOD, Karachi American School, Pakistan
Having added nearly 50 new students this year, Karachi American School isn’t exaggerating when they say they are growing quickly. This growth means many things for the school: more diversity amongst students and faculty, more options at the cafeteria, and even more candidates for the school’s gold medal Volleyball and National History Day teams! But it also means more demands on the school’s infrastructure, chiefly on its water supply. Karachi has one of the most at-risk aquifers in the world, but KAS cannot sacrifice students’ health or the appearance of the school due to conditions in the city. We made a collective decision to install a reverse osmosis (RO) device, which is able to process over 10,000 gallons of water per day. For those of you who are not clear on the concept: our system takes advantage of the fact that water naturally undergoes osmosis—preferentially passing across a membrane to the side with greater concentration of solute—but reverses the process using high pressures. We thus create clean water from unclean or salty water.
Junior and Senior AP science students were especially intrigued. They asked their science teachers to help them understand why we as a school needed such a device. KAS AP Chemistry students designed a lab that tested well water and RO water for the presence of electrolyte, pH, turbidity (cloudiness), and absorbance. They determined that the RO process effectively removed over 98% of dissolved solute in the water, making it safe for washing and watering. KAS AP Environmental Science students took their classmates’ discoveries even further, designing an analysis of the RO and well water for the presence of bacterial colonies. They discovered a marked decrease in the presence of total coliforms after RO processing.
After completing their labs, students shared their discoveries with their peers and teachers, proving that skills they were learning in their science classes pay off. In the process, they also showed how we have made over 1,000,000 gallons of clean water in a city where water is at a premium.
Published in ISS NewsLinks: Volume XXXII Number 1