CrioPurA: a macroporous polymeric cryogel for sequestering and/or removing toxic contaminants.

N-methyl-D-glucamine (NMG) is a chelating molecule used for environmental purposes for its high efficiency and selectivity versus metal ions species. The technology namely CrioPurA  regards the realization of NMG-based hydrogels, produced by cryo-polymerization in water. The synthesis of ad-hoc functionalized polymeric materials with chelating groups is a sustainable and low-cost strategy to obtain adsorbent materials. In particular, the technique adopted for the realization of  material allows to obtain different structures as well as shapes of different sizes, with high porosity, permeability and excellent sequestering action towards boron, arsenic, chromium and other metals ions from the water. CrioPurA can be regenerated, reused and adapted to existing water treatment plants.

“Water is life”. These words are probably the most powerful and realistic message, but it is often used as a cliché. In fact, water has been an inexhaustible resource for too long, until growing pollution outlined the need to protect current supplies. In particular, toxic heavy metal ions introduced into the environment by existing industrial activities accumulate biologically and cannot be easily decomposed, threatening human health throughout the entire food chain. Among the possible removal strategies, adsorption is considered as one of the most feasible, versatile and low cost methods, relying on the physical and/or chemical interactions between the targeted molecules and the adsorbent substrate. However, water contamination is a complex problem that cannot be solved with a single material. Depending on the characteristics of industrial wastewater, it is necessary to use targeted technologies for the elimination of specific contaminants. For example, for the tanning industry Cr(VI) and dyes are the most relevant species to be treated, while for agriculture pesticides and boron must be eliminated. Our work aims to focus attention directly on these specific needs by offering innovative and sustainable solutions.

CrioPura finds a perfect collocation as resins for purification of wastewater, to remove As(V) from groundwater, Cr(VI) from water deriving from tanning, dyes, textiles, boron from water deriving from microelectronics industries.  In particular, the superior absorption capacity of arsenic (76.3 mg/g) and chromium (130.9 mg/g) if compared to commercial products (14,7 mg/g (As) e 29,3 mg/g (Cr)), is remarkable.

The first case study will concern the application of technology for the treatment of polluted groundwater.

The main advantages over commercial resins consist in: (i) the presence of about 98% of active chelating part; (ii) the peculiar interconnected macroporous architecture obtained by cryo-synthesis. In particular, the technique adopted for the realization of our material allows to obtain different structures as well as shapes of different sizes, with excellent mechanical properties and high porosity, permeability and sequestering action towards boron, arsenic, chromium and other metals ions from the water.

CrioPurA, containing 98% of NMG active part, is able to complex higher quantities of metal ions than the current commercial resins. Furthermore, its interconnected macroporous nature provides rapid water diffusion pathways, resulting in full access to all available chelating sites, thereby increasing ion sequestration.