Analysis was carried out to determine the physicochemical characteristics – morphological and structural, electrokinetic properties, elemental composition and functional groups – of peat, with a view to its use as a potential adsorbent of heavy metal ions from aqueous solutions. A significant part of the study comprised tests of adsorption of nickel(II) and lead(II) ions from model solutions. It was determined how the parameters of the adsorption process (time, pH, quantity of sorbent) influence the effectiveness of removal of nickel(II) and lead(II) ions. The adsorption kinetics are also described, using a pseudo-first-order model and pseudo-second-order models of types 1–4. The results show strong correspondence to a pseudo-second-order kinetics model of type 1 (r2=0.999 for all initial concentrations). Another key part of the analysis was the use of the Langmuir and Freundlich models to determine the adsorption isotherms. The experimental data were in strong correspondence with Langmuir’s isotherm model. The sorption capacities of peat with respect to nickel(II) and lead(II) ions were 61.27mg(Ni2+)/g and 82.31mg(Pb2+)/g. Desorption tests confirmed the possibility of reusing peat as an effective sorbent of environmentally harmful metals. A mechanism is also proposed for the adsorption of Ni2+ and Pb2+ ions on adsorbent
Novel, functional materials based on chitin of marine origin and lignin were prepared. The synthesized materials were subjected to physicochemical, dispersive-morphological and electrokinetic analysis. The results confirm the effectiveness of the proposed method of synthesis of functional chitin/lignin materials. Mechanism of chitin modification by lignin is based on formation of hydrogen bonds between chitin and lignin. Additionally, the chitin/lignin materials were studied from the perspective of waste water treatment. The synthetic method presented in this work shows an attractive and facile route for producing low-cost chitin/lignin biosorbents with high efficiency of nickel and cadmium adsorption (88.0% and 98.4%, respectively). The discovery of this facile method of synthesis of functional chitin/lignin materials will also have a significant impact on the problematic issue of the utilization of chitinous waste from the seafood industry, as well as lignin by-products from the pulp and paper industry.