New Methods and New Types of Functionalised Nanocomposites Intended for the Ecological Depollution of Waters

Abstract

In this chapter we have presented and investigated the specific mechanisms underlying the reticulation, separation and encapsulation processes of organic pollutants. Specific depollution mechanisms, as well as the main depollution parameters (yield, efficiency), have been investigated by testing a polyfunctionalized nanocomposite material (MOF-DP) on three types of water charged with organic pollutants. The polluted waters on which the depollution features of MOF-DP have been investigated came from various pollution sources: milk processing industry, medicine industry, sewage waters. The investigations’ secondary aim was to determine the effects of organic pollutants on the morphological and morphochemical structure of the obtained MOF-DP, as well as to determine how they influence the depollution parameters. It was intended, in particular, to check the range of pollutants that MOF-DP is able to separate, in order to determine the type of chemical functionality of pollutants capable to establish reticulation relations with the functional structure of the composite. The reticulated functionalities are a direct measure of the depollution efficiency of the obtained material, by defining the range of separated pollutants and the extent to which the depollution was carried out. The investigation processes included various analytical techniques, in order to confirm, through complementarity (SEM, TEM, EDX, FTIR, GC-MS), the depollution parameters and the morphostructural characteristics of MOF-DP, both before the testing and after its completion. The investigation results confirm the reticulation, encapsulation and degradation mechanisms of the pollutants that the authors proposed in chapters „New methods and new types of functionalised nanocomposites intended for the ecological depollution of waters” and „Nanocomposite materials with oriented functionalized structure”. The acquired experimental data have shown that the obtained MOF-DP presents high pollutant separation yield and efficiency. The concentrations of most decelated pollutants and of those partially decelated in depolluted water were below the detection limit, showing the applicative potential of this type of materials. The aim of the investigations of the morphological and morphochemical structure which we have carried out was to identify and quantify the critical parameters that influence the processes of encapsulation and degradation of pollutants. The acquired experimental data indicate that MOF-DP is able to reduce the level of organic pollution in surface waters by up to two orders of magnitude (the observed typical values have a separation factor of 20 ÷ 50 x). The oxide materials with a functionalised mixed structure represent a viable solution for the removal of organic pollutants in surface waters, having the most favourable applicative potential in terms of economy, depollution yield and efficiency.