Particulate medium prepared from partially decomposed organic matter for selective sorption between competing metal ions in aqueous solutions

Abstract

A process for the preparation of a granulated or pelletized sorption medium from a partially decomposed organic material like peat, followed by low-temperature thermal activation of the sorption medium to produce a high degree of granule or pellet hardness balanced against an efficacious level of ion-exchange and adsorption capacity, followed by chemical treatment of the sorption material via a preselected solution of soluble salts (called 'APTsorb II*M') for use in a wastewater treatment process where competing toxic metal cations are present in the wastewater is provided by this invention. Depending upon the Mcations contributed to the peat granule sorption activity sites by the preselected salt used in the salt solution treatment step, the granules exhibit a selectivity α of a first type of more-toxic metal cations (such as cadmium, lead, copper, or other metals at high concentrations) over a second type of less-toxic metal cations of (such as zinc, aluminum, or iron) in the wastewater; greater adsorption activity for the first type of more-toxic metal cations; and greater breakthrough capacity for the first type of more-toxic metal cations. This allows the end user to target the more-toxic metals for adsorption by the sorption medium containing the cations contributed by the preselected solution of soluble salts.