On multivalued weakly Picard operators in partial Hausdorff metric spaces

We discuss multivalued weakly Picard operators on partial Hausdorff metric spaces. First, we obtain Kikkawa-Suzuki type fixed point theorems for a new type of generalized contractive conditions. Then, we prove data dependence of a fixed points set theorem. Finally, we present sufficient conditions for well-posedness of a fixed point problem. Our results generalize, complement and extend classical theorems in metric and partial metric spaces

Cross-Linked Chitosan-Based Hydrogels for Dye Removal

International audienceSynthetic dyes are a major class of recalcitrant organic compounds, often occurring in the environment as a result of their wide industrial use. More than 100,000 dyes are commercially available. Synthetic dyes are common contaminants, many of them being toxic or carcinogenic. Colored effluents from industrial plant are also perceived by the public as an indication of the presence of a dangerous pollution. Even at very low concentrations, dyes are both highly visible, inducing an esthetic pollution, and impacting the aquatic life and food chain, as a chemical pollution. Dye contamination of water is a major problem worldwide and the treatment of wastewaters before their discharge into the environment is a priority. Dyes are difficult to treat due to their complex aromatic structure and synthetic origin. In general, a combination of different physical, chemical and biological processes is often used to obtain the desired water quality. However, there is a need to develop new removal strategies and decolorization methods that are more effective, acceptable in industrial use, and ecofriendly. Currently, there is an increasing interes