Discipline: Ecology Environmental and Earth Sciences
Subcategory: Environmental Engineering
Claralys Hernández - University of Puerto Rico-Mayagüez
Co-Author(s): Amarillys Avilés, University of Puerto Rico-Mayagüez
Pollution of drinking water sources such as surface waters has become a serious environmental problem, caused mostly by the excessive use of agrochemicals. In the US, where atrazine is one of the most widely used herbicides, traces of it have been found in drinking water sources. This research studied the fabrication of a porous recycled glass substrate with immobilized TiO2 nanoparticles for atrazine photo-degradation under UV light exposure. The glass filter was fabricated by sintering clear recycled glass cullets (MG-30) between 950ºC to 975ºC for 45 to 75 minutes whereas the TiO2 particles were immobilized by heat treatment after gravitational deposition onto the surface of the sintered glass. Compression strength and percolation rate of the composite filter were evaluated as well as the structure of the immobilized nanoparticles via x-ray diffraction (XRD) analysis. Most importantly, the filter’s degradation capacity of atrazine was assessed. Our results demonstrated that the percolation rate declined as the sintering temperature and time increased, and that the heat treatment improved the immobilization of the nanoparticles. The XRD analyses confirmed the anatase polymorph phase of the TiO2 whereas a reduction of atrazine levels was measured by HPLC analysis with apparently total degradation after 12 hours of UV-light exposure. Further, the results suggest a maximum degradation rate was obtained with 0.55 g of immobilized TiO2 and low initial concentration of the contaminant. Finally, by using smaller particle sizes of nanoparticles the degradation rate was improved by almost 50%. In closing, the results obtained are essential to determine the viability of implementation of this technology as a filtration device for the removal of atrazine from surface waters.
Funder Acknowledgement(s): The National Science Foundation (NSF) under grants N0833112 & 1345156 (CREST program). The USDA-NIFA Center for Education and Trainings in Agriculture and Related Science (CETARS) under grant No. 2011-38422-30835.
Faculty Advisor: Oscar Marcelo Suárez, firstname.lastname@example.org
Role: In this research I was working specifically with the phase of atrazine degradation experiments. I performed different analyses varying contaminant concentrations and the amounts of nanoparticles. In addition, executed an efficiency experiment of the glass substrate with the immobilized nanoparticles to determine its useful life. I collaborated with the samples analyses in the HPLC unit. As well, I conducted experiments using different titanium dioxide nanoparticles sizes to compare its effect in the degradation rate with the results obtained in previous experiments. In those experiments we observed an improvement in the degradation rate by almost 50% when using smaller nanoparticles sizes.