An important goal in environmental research for industrial activity and sites is the investigation and development of effective adsorbents for chemical pollutants that are widespread, inexpensive, unharmful to the environment, and have the required adsorption selectivity. Organoclays are adsorption materials that can be obtained by modifying clays and clay minerals with various organic compounds through intercalation and surface grafting. Organoclays have important practical applications as adsorbents of a wide range of organic pollutants and some inorganic contaminants. The traditional raw materials for the synthesis of organoclays are phyllosilicates with the expanding structural cell of the smectite group, such as montmorillonite. Moreover, other phyllosilicates and inosilicates are used to synthesize organoclay to a limited extent. The purpose of this review was to analyze the possibility of using minerals of other groups with different abilities to expand the structure and structural charge for the adsorption of chemical environmental pollutants. The structural characteristics of various groups of phyllosilicates and chain minerals that affect their ability to modify organic surfactants and the adsorption properties of prepared organoclays were reviewed.

Humic substances (HS) with or without chemical modification can serve as environmentally benign and inexpensive adsorbents of potentially toxic trace elements (PTTEs) in the environment. The present study investigated the absorption of Pb, Zn, Cu, and Ni by natural and potassium persulfate (K 2 S 2 O 8 ) modified humic acids (HA) isolated from a lowland peat through batch experiments. The adsorption of the studied PTTEs on the natural HA was satisfactorily described by the Langmuir isotherm model with maximum monolayer adsorption capacities of 318.2, 286.5, 225.0 and 136.8 mmol/kg for Pb, Cu, Zn and Ni, respectively. A thorough characterization of the natural and modified HA using 13 C nuclear magnetic resonance (NMR) spectroscopy demonstrated that the chemical modification of natural HA with K 2 S 2 O 8 led to an increase in the content of carboxyl groups, and ketone and quinoid fragments in the HA structure. Consequently, the modified HA absorbed 16.3, 14.2, 10.6 and 6.9% more Pb, Ni, Zn and Cu, respectively, than the original natural HA. The isotherm data modelling together with adsorbent characterization suggested that the adsorption of PTTEs was controlled mainly by chemisorption mechanisms where inner-sphere complexations of metal ions with HA functional groups took place.

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In this study, the effect of granular activated carbon on the physical properties of soils containing copper pollution was presented. The result showed activated carbon could exert a positive effect on accelerating the process of restoring the physical properties of the soil, due to the high porosity and the specific surface area. The soil after remediation with the activated carbon showed better structural state and more water-holding capacity.

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