A hydrogel product for adsorption wherein water non-soluble support matrix is cross-linked with polymers which give rise to a water swellable adsorbent. As support matrix an organic polymer or a combination of such are used; e.g. polysaccharides such as agar, cellulose, or starch, proteins and components of proteins and polysaccharides. The support matrix is substituted with a first soluble polymer material chemically bound to the support matrix, whereupon additional polymer materials are built into the primary synthesized support matrix polymer complex through different kinds of cross-oinks whereby optionally the support matrix is present in the form of an acid- and base-stable residue.
A blended composition of hydrogel polymer granules capable of selectively removing toxic dissolved metal species from water containing abundant innocuous species, and spacer particles which minimize contact between contiguous polymer granules is provided for reducing the impedance of water caused to flow through a confined bed of the composition.
