SORBENT-BASED METHOD OF SOILS DETOXIFICATION FROM HEAVY METALS
Abstract. The sorbent-based method is one of the key methods for solving the problem of limiting the mobility of pollutants and the effective implementation of reclamation works. Despite the level of knowledge of the problem, the use of the sorbent-based method is of a fragmented experimental nature. Objective: to study the experience of implementing the sorbent-based method for the adsorption of heavy metals in order to determine the most promising compositions of sorbents for further research work on their improvement. Methods: General scientific methods were used, such as dialectical, historical, analysis, synthesis, comparison, grouping, as well as systematic and empirical approaches. Results: The presence of pluralism of definitions in relation to the term “heavy metals”was revealed. The main criterion for attribution is the relative atomic mass of more than 50 g/mol. An additional criterion is the density, which is approximately equal to or greater than the density of iron (rounded 8 g / cm3). There are other classifications that rely on threshold density or atomic mass values. It is proved that the main role of the immobilization of heavy metals is their transfer to new, more geochemical stable phases by sorption, precipitation, and complex formation processes. The widespread use of the sorbent-based method, which solves the problem of converting heavy metals into a sedentary form and difficult-to-dissolve compounds, has been identified. It is revealed that an important process affecting the mobility of heavy metals in the soil is their fixation with humus. It is established that rocks and minerals have pronounced sorption properties. The most common rocks are clays. They are characterized by a significant sorption capacity and a high specific surface area. In order to increase the sorption properties, the materials can be subjected to various modifications. Peat occupies a special place among effective natural sorbents. The development of technologies for the creation and use of new sorbents made from industrial waste is a promising direction. A method of remediation based on the use of ameliorants–stabilizers of heavy metals has been developed: among the mineral elements of the solid phase, fine clay and ferrous minerals are isolated; compost and manure are often used as organic stabilizers. The possibility of rerational use of industrial waste components as meliorants-stabilizers of heavy metals is investigated, and the sediments of water treatment at filtration stations are of interest in this regard. The remediation potential of water treatment sediments can be enhanced by joint application with natural or modified peat.
