The objective of the project is to study properties of sorbents based on oxidized coal (oxihumolite) and chitosan pertinent to their metal ion sorption ability, and optimization of these properties by physical and chemical modification of the sorbents for use in waste/groundwater treatment and construction of active geochemical barriers. Operational range and selectivity of the sorbents for specific waste will be extended by mutual immobilization of coal humic substances and chitosan in a suitable ratio within a composite sorbent. Composition, structure, surface and porous properties of the sorbents will be characterized. Equilibrium sorption and column flow experiments will be performed with selected metals both as single-metal and competitive experiments. Stability of the sorbents and their ability to recover will be monitored. Efficiency and life cycle of the sorbents at decontamination of real (or simulated) waste waters will be tested.