Innovative materials for miniaturized sample preparation techniques, environmental and food packaging applications

Abstract

In Europe approximately 2.5 billion tons/year of waste are produced, deriving from households, agriculture, livestock, and industrial activities. Moreover, it has been estimated that, in 2011, 20% of the manufactured food went to waste, for a total of nearly 130 thousand tons. The recent increase in worldwide population produced an acceleration of economic development, intensifying manufacturing activities to satisfy the worldwide demand, thus requiring a great effort to food system and environmental policies in keeping pace. Economic processes still based on a linear approach constitute a serious threat to the environment, sustenance of food system, and biodiversity. This is not only for the amount of waste that is produced, but also for the emission into the environment of substances and biological entities that alter the equilibrium in ecosystems and pose risks to human health. Up till now only a reduced portion of contaminants are monitored by competent authorities, whereas a lot of emerging contaminants are not under control due to the lack of knowledge and absence of specific regulations. The European Union has enacted a series of directives and regulations that aim at improving the waste management policies and regulating certain pollutants for a more sustainable development. Examples are represented by the Directive EU 2018/851 for waste management, the Regulation EU 2019/1021 for limiting the emission of persistent organic pollutants (POPs), and the NORMAN project (started in 2005) to gain knowledge towards emerging contaminants. In December 2019, the European Commission announced the so-called European Green Deal, comprising a series of policies aimed at meeting the climate objectives of the next future. The main figures of merit include the reduction of European greenhouse gasses emission by 55% before 2030 (with respect to 1990 levels) and the achievement of the climate-neutrality by 2050 to create a toxic-free environment. Along with the regulation of certain pollutants, as among which the POP regulation previously mentioned, it is fundamental to re-design economic processes to make them more circular. Within this frame of reference, the advancements in the field of Materials Science might help in reaching the climate requirements set by the European Green Deal. This Thesis, in the framework of the PhD Program in Materials Science and Technology (Department of Chemistry, Life Sciences and Environmental Sustainability; University of Parma) aims at exploring the potential of novel materials for applications in the field of Analytical Chemistry, and on materials devoted to packaging, and environmental applications. The development of analytical methodologies able to keep pace with very low contamination thresholds and fast-changing regulations is of vital importance, not only to comply to the regulating authorities, but to enable people in making decision with confidence. Additionally, the advent of Green Analytical Chemistry has posed new challenges in the development of analytical methods focusing on their impact on the environment. In this context, novel sorbent materials and devices for miniaturized sample treatment offer a plethora of possibilities for the development of methods with enhanced selectivity, sensitivity, and lower detection limits, reducing both the amount of sample required for the analyses the use of organic solvents. The chapters dedicated to this topics explores the capabilities of carbon nanotubes and magnetic composites for the miniaturized extraction of emerging contaminants and priority pollutants from water samples, paying attention to the Green Analytical Chemistry principles. Along with the introduction of technologies with a reduced climate footprint, it is fundamental to implement strategies able to remediate contaminated ecosystems to effectively depollute the environment. In this context, bioremediation provides a sustainable and cost-effective approach for the removal of pollutants from contaminated ecosystems. Along with the metabolic activity of living organisms, the use of carbon-based materials could simultaneously aid the removal of certain pollutants, promoting the survival of microbial communities, to increase their bioremediating effect. The chapter dedicated to this topic explores the potential of carbon-based materials and aquatic plants in reducing the concentration of a class of organic micropollutants in sediments, for the development of a green bioremediation technology. Finally, the reduction of waste or its reuse as raw material for novel applications are fundamental to decrease the overall climate footprint. Within this frame of reference, the manufacturing of active food packaging could help in preventing food waste. The impact of active food packaging materials could increase even more dramatically if the active ingredients exploiting antibacterial and antioxidant activity can be derived from natural and renewable sources, like in the case of essential oils and their active components, substituting conventional food preservatives. However, efforts have to be made in making such substances more appealing for technological applications. About this topic, one chapter is dedicated to the use of chemometrics for predicting the formation of cocrystals based on the active components of essential oils, to extend their applicability in fields ranging from agriculture to food packaging. On a closing note, the fabrication of biocomposites to be used as building materials or secondary packaging materials could offer a valuable solution for the valorization of waste in the context of circular economy. This process could become even more interesting when the feedstock is represented by toxic wastes, integrating bioremediation and the production of safe biocomposite materials in a single step. In this context, a chapter is dedicated to the development of a biocomposite material starting from cosmetic waste.