Purifying Pollutant; Photodegradation and Aqueous Tobacco Effluent

Undergraduate #207
Discipline: Chemistry and Chemical Sciences
Subcategory: Water

Alexa McLeod - Howard University
Co-Author(s): Moussa Diop, University Cheikh Anta Diop de Dakar, Dakar, Senegal

This principle of this experiment analyzed the purification effects an energy of light radiation greater than the bandgap of a semiconductor, otherwise known as photodegradation. In order to conduct this study, Titanium dioxide (TiO2) was used as a semiconductor. The process of photodegradation is a beneficial purifying method due to the reliability and affordability of materials used. Since the primary element of photodegradation is sunlight, photodegradation is utilized in many African and Southeast Asian countries. This would allow many small and isolated areas to have access to clean drinking water in a matter of hours. Though there happens to be three main types of Titanium dioxide—anatase, brookit and Tinferous sand (sometimes referred to as rutile)—the purification effects of both anatase and Tinferous sand were measured in this study (anatase and Tinferous sand contain higher amounts of Titanium dioxide). The sand and anatase were tested against sample of natural, tobacco effluent and set out in controlled areas for specified amounts of time—eight hours at time in direct sunlight. Former research has concluded that using photodegradation, also as known as using solar energy as a catalyst for methods of waste water purification, has decontaminated waste water carrying bacterium. Before experimentation was conducted, it was hypothesized that the Tinferous sand would purify the effluent better than the anatase due to the physical characteristics of the agent. The sand is dark black in color and because the color absorbs solar energy better than the white color of the anatase, it was believed that the sand would have a higher purification rate. The hypothesis was found to be conclusive and the sand treated more effluent than the anatase. Future research in this study would be used to find how often the Tinferous sand can be used before the purification rate decreases.

Funder Acknowledgement(s): Global Education and Awareness Research Undergraduate Program (GEAR-UP); National Science Foundation (NSF).

Faculty Advisor: Dwayne Bryant, dwayne.bryant@bison.howard.edu

Role: I conducted the portion of research in which the Tinferous sand was tested against aqueous tobacco effluent. I was responsible for arranging materials, monitoring the study and collecting adequate data.