Active Multipurpose Hydrogels and Low-Impact Materials for Environmental Remediation

Finding new strategies for environmental monitoring and remediation, portable and locally applicable in places of interest, is essential to respond to the pressing demand for clean water and soil. At the same time, it is necessary that the new solutions are based on simple materials and techniques, they have low cost and they are characterized by low environmental impact.

In this regard, we have started developing hydrogels based on natural polymers (i.e. alginate, chitosan, pectin..) which can be easily functionalized with molecular receptors (able to control interaction with particular classes of pollutants) and optical antennas (able to concentrate light in their surrounding and facilitate pollutant detection with spectroscopic techniques and pollutant photo-degradation). In this way, it is possible to combine absorption capabilities and easy manipulation, typical of hydrogels, with functional activities typical of the other building blocks and obtain multifunctional systems, which can perform both pollutant detection and removal.

As anticipated, great attention is dedicated to the environmental sustainability of the production process, and different studies are conducted for the research of new procedures for green extraction of natural polymers.

Over the years, various systems have been developed for active removal of different types of pollutants. Examples are food-waste based membranes for Cr(VI) reduction and adsorption and oxide macro-beads for dye and pharmaceutical compounds adsorption and photo-degradation.

References:

Hydrogels and natural polymers extraction:

• Irene Vassalini, Giovanni Ribaudo, Alessandra Gianoncelli, Maria Francesca Casula, Ivano Alessandri, Plasmonic hydrogels for capture, detection and removal of organic pollutants, Environmental Science: Nano (2020), 7, 3888-3900, DOI: 10.1039/D0EN00990C.

• Laura Benassi, Ivano Alessandri, Irene Vassalini, Assessing Green Methods for Pectin Extraction from Waste Orange Peels, Molecules (2021), 26 (5), 1766;D OI:10.3390/molecules26061766

• Marina Maddaloni, Irene Vassalini, Ivano Alessandri, Green Routes for the Development of Chitin/Chitosan Sustainable Hydrogels, Sustainable Chemistry (2020), 1, 325-344.

Other systems for pollutant removals:

• • Irene Vassalini, Marharyta Litvinava, Ivano Alessandri, All Food Waste-Based Membranes for Chromium(VI) Removal, Environmental Sustainability (2021), 4(2), 429-435, DOI:10.1007/s42398-020-00132-y

  • Irene Vassalini, Joana Gjipalaj, Stefano Crespi, Alessandra Gianoncelli, Mariella Mella, Matteo Ferroni, Ivano Alessandri, Alginate‐Derived Active Blend Enhances Adsorption and Photocatalytic Removal of Organic Pollutants in Water, Advanced Sustainable Systems (2020), DOI: 10.1002/adsu.201900112

  • S. Mura, Y. Jiang, I. Vassalini, A. Gianoncelli, I. Alessandri, G. Granozzi, L. Calvillo, N. Senes, S. Enzo, P. Innocenzi, L. Malfatti, Graphene Oxide/Iron Oxide Nanocomposites for Water Remediation. ACS Applied Nano Materials (2018), DOI: 10.1021/acsanm.8b01540

  • Gjipalaj, I. Alessandri, Easy recovery, mechanical stability, enhanced adsorption capacity and recyclability of alginate-based TiO2 macrobead photocatalysts for water,  Journal of Environmental Chemical Engineering 5 (2) (2017), 1763-1770, doi: 10.1016/j.jece.2017.03.017