Estudis d’adsorció de nanopartícules metàl•liques en sòls

Abstract

In the last years the uses of metallic nanoparticles have considerable increased in products for a human use, and this fact have arisen an uncertainly respect to the impact of this nanoparticles in the human health and in the environment. Given the use on the wastewaters and the sewage sludge for sewage in agriculture, the nanoparticles finally arrive to the environment in general and in the soils particularly. Exist some studies in the literature about the interaction of the metallic nanoparticles in soils, but these studies indicate that still many aspects are unknown. The interaction between nanoparticles and soil depend of some factors like; the characteristics of the soil (ionic exchange capacity, particle size distribution …) and the characteristics of the nanoparticles (size, surface …). Simultaneously, the need to develop news quick and easy technical analysis has been arise to carry out quantitative measurements of metallic nanoparticles in environment samples. The aim of this final degree project is carry out a study about the interaction of silver nanoparticles and soil. To achieve this goal, have been carried out different studies, including the possibility of realize quantitative determinations of silver nanoparticles using ICP-OES, stability and manipulation studies of nanoparticles and kinetic and equilibrium in soils studies, among others. In addition, have been carried out complementary studies about comparison of analytical techniques (ICP-OES and TXRF) and qualitative analysis of silver nanoparticles and ionic silver through a recent developed method called single-particle (SP-ICP-MS).

So in this final degree project has been carried out the determination of silver nanoparticles using ICP-OES without previous digestion and have been proved that some manipulations (to take an aliquot or filtration) don’t affect to their analysis, but the storage conditions of the nanoparticles have and important affect. However, has been studied the adsorption kinetic of silver nanoparticles in soils with different characteristics. Finally, has been carried out qualitative measurements using single-particle method (SP-ICP-MS) to have allowed distinguishing between silver nanoparticles solutions and ionic silver solutions. The measurements, through this methodology, of solutions who have been in contact with the soil and the real samples have allowed verify the presence of silver nanoparticles form in these solutions