Institute: Puerto Rico
Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $35,796
Principal Investigators: Pedro Tarafa, Sylvia RodriguezAbudo
Abstract: The indiscriminate use of pesticides for agriculture has resulted in the presence of a variety of persistent contaminants in surface and ground waters, which compromise the water quality of these sources. An example of this is atrazine, which is an herbicide that is widely used by farmers and is of particular concern due to its relatively long half-life and low adsorption in soils. In addition, it is a potent endocrine disruptor and has been associated to human reproductive disorders and birth effects. Recent studies have evaluated the degradation of various organic pollutants by photocatalysis, using wide band gap semiconductors to promote advanced oxidation processes (AOPs). One of those appealing alternative photocatalytic compounds is titanium dioxide (TiO2). However, TiO2 usage has a few shortcomings; for instance, TiO2 can be excited only under UV light irradiation with wavelengths shorter than 400 nm. One strategy to overcome this limitation is by doping the bulk phase of TiO2 with various metal ions. This modification has shown remarkable visible light absorption efficiency and enhancement of photocatalytic activity. Among a list of transition metal ions evaluated, Fe(III) has shown to be one of the most reactive. The present proposal aims to receive another year of funding to accomplish the second stage of this endeavor, which consist in conducting more research to develop a gravity-influenced inclined plane impregnated with iron-grafted TiO2 nanoparticles for the degradation of atrazine under the influence of sun light via photodegradation. The first stage (still in progress) consisted in: 1) the establishment of a protocol for the chemical modification of the TiO2 surface to dope the Fe(III) ions; and 2) evaluation of the nanocomposite potential for photodegradation of atrazine under visible light. The proposed tasks for the second stage will be to: 1) immobilize the Fe(III)-TiO2 nanoparticles in a PVC matrix without compromising the nanocomposite integrity and catalytic properties; and 2) design, construct and evaluate a lab-scale inclined plane for effective photodegradation of atrazine under the influence of visible light. The realization of this project will provide essential data to set the foundations for the development and establishment of an easy-to-use, energy-efficient water treatment process for the removal/destruction of pesticides-related contaminants in water.