Browsing by Keyword "TiO water contamination"
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Item Evaluation of photocatalytic nanoparticle release to the aquatic environment(TANGER Ltd., 2010) Zorita, Saioa; Olabarrieta, Josune; Monzón, Oihane; Rioja, Nerea; Benguria, Pablo; Scifo, Lorette; ADAPTACIÓN AL CAMBIO CLIMÁTICO; MATERIALES PARA CONDICIONES EXTREMASNanotechnology creates possibilities to produce new products with novel functionalities and improved characteristics. Therefore the incorporation of engineered nanoparticles (ENP) in commercial products is progressively increasing and so is the potential for release of these novel materials into the environment. In fact, the occurrence and release of titanium nanomaterials in a wastewater treatment plant has already been proven. This implies that nanomaterials will reach the aquatic environment and that they could represent a risk to aquatic organisms and humans. We have studied the discharge of nano-TiO2 (nTiO2) to water for two case studies related to photocatalytic nanomaterials: A- The release of nTiO2 from two photocatalytic coatings under accelerated aging under a water flow and B- The release of nTiO2 though a filtration pilot plant from tap water containing 2 mg/L nanoparticles. Case A. The influence of environmental parameters (water matrix, UV-light) was investigated while the consequences of aging were evaluated under different endpoints, among them, the release of TiO2 nanoparticles. Despite that TiO2 emissions were observed for both coatings, only one of them presented mechanical damages. TiO2 concentrations up to 150.5 μg/L were detected in the aging water. Case B. Preliminary experiments were conducted at laboratory scale to determine optimum polymeric material as well as pore size. Among the common commercial materials PVDF showed the best performance. Two different industrial hollow fiber cartridges were tested with a pore size of 0.45 μm (microfiltration) and 0.03 μm (ultrafiltration). TiO2 was detected at an average concentration of 51 μg/L in the filtered water.Item Synergy effect in the photocatalytic degradation of pharmaceuticals on a suspended mixture of titania and activated carbon(TANGER Ltd., 2010) Rioja, Nerea; Benguria, Pablo; Scifo, Lorette; Zorita, Saioa; MATERIALES PARA CONDICIONES EXTREMAS; ADAPTACIÓN AL CAMBIO CLIMÁTICOPhotocatalysis is currently being considered for many environmental applications such as water decontamination. This is due to its ability to degrade organic pollutants to CO2, water and mineral acids. In TiO2 photocatalysis, UV radiation is needed to create hole-electron pairs which can be transferred to water to form oxidizing species. However this process generally suffers low apparent quantum yield, mainly due to the rapid recombination of the photogenerated electron-holes. In order to improve quantum yields, the addition of activated carbon (AC) has been suggested. As adsorption is a key point in photocatalysis, the addition of AC can aid to increase pollutant's degradation kinetics by augmenting their adsorption onto the TiO2-AC interphase. Carbon has also been suggested to act as an electron sink which may retard the recombination of electron-hole pairs. The aim of our work is to study the synergistic effect of TiO2-AC on the removal of five different pharmaceuticals from water. Two different ACs were tested to identify the best working conditions. Different routes to combine TiO2-AC were as well studied. Experiments under the following conditions: UV+TiO2, UV+AC and UV+TiO2+AC were performed in order to determine % of removal by photocatalysis, adsorption and by the synergistic effect of TiO2-AC. Drugs degradation in a real matrix such as river water, and not only in ultrapure water, was also investigated.