Discipline: Chemistry and Chemical Sciences
Subcategory: Pollution/Toxic Substances/Waste
Kristiana Watson - Arkansas State University
The adsorption of 4-n-Nonylphenol (4-n-NP), a persistent emerging contaminant, onto the surface of Hematite and Goethite was studied using ATR-FTIR spectroscopy. The adsorption characteristics were then used to test the feasibility of using iron minerals to naturally removal these persistent emerging organic contaminants from polluted waters. The adsorption kinetics for hematite and goethite show that equilibrium was reached in less than 24 hours, with the fastest kinetics to saturation achieved on hematite. Adsorption studies show that Langmuir model bests fits the data with the highest ‘removal capability’ as calculated from adsorption studies, observed with goethite with a calculated 4-n-NP maximum adsorption that was 3 times more than that of hematite. This higher attributed maximum capacity on the surface of goethite was attributed the presence of ?OH species that are found on the surface of goethite more than the surface of hematite. When the pH was varied, uptake of NP increased up to the pKa of 4-n-NP was reached, and then the adsorption decreased. Maximum adsorption was achieved close to pKa of 4-n-NP, with values matching those acquired from adsorption isotherms and kinetic studies.
Funder Acknowledgement(s): Dr. Hashim Ali
Faculty Advisor: Dr. Hashim Ali, hali@astate.edu
Role: My part of the research involved conducting the reactions for the two types of oxides with the NP for the absorption data, as well as collecting the pH data using pH electrodes. I also had to analyze the data once the reactions were analyzed through the ATR-FTIR, which I also did.