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Relevance. At present, the problem of soil pollution with heavy metals, which are accumulated in the body of animals and plants, causing various toxic effects, is especially acute. Despite the existence of various methods of reclamation of disturbed lands, as a rule, their application is inefficient or expensive, especially when it comes to abnormally high concentrations of heavy metals. Thus, an extremely urgent task is to find effective and inexpensive ways to recultivate lands contaminated with high concentrations of heavy metals. The article considers one of the promising areas for the reclamation of such lands using a mixture obtained from the accumulated waste of lignin-containing sediments from the pulp and paper industry of Baikal Pulp and Paper Mill as sorbents. Aim. To study and evaluate the effectiveness of using a mixture, which includes frozen lignin-containing sediments of Baikal Pulp and Paper Mill, as heavy metal sorbent. Methods. To assess the sorption efficiency of the obtained sorbent from the frozen sediments of sludge-lignin, the samples of anomalously contaminated soils were taken from the industrial site of the former battery plant "Vostsibelement", located in Svirsk, Irkutsk region. To determine the surface structure of the obtained sorbent for the presence of micro-, meso-, and macropores, its surface was surveyed using a JEOL two-beam system. IR spectroscopy was used to establish the types of bonds between the sorbent and the extracted metals. Results. The studies have shown that the resulting sorbent from the frozen lignin-containing sediments of Baikal Pulp and Paper Mill has a porous structure with a predominance of mesopores, sorbing heavy metal ions, while a large number of micropores contributes to the occurrence of chemical sorption. The obtained IR spectra indicate the possibility of chemical sorption of lead as a result of the reaction of substitution of a hydrogen atom in various hydroxyl groups of the sorbent of the group of aromatic or carboxyl structures. At the same time, the resulting sorbent in terms of its sorption properties is not inferior to commercial natural sorbents – bentonite clay and grassroots peat. The conducted studies allow us to make a positive conclusion about the possibility of using the developed mixture as a sorbent for the immobilization of heavy metals during the reclamation of lands that are contaminated with high levels of heavy metals, including lead.

The relevance. The waste of Baikal Pulp and Paper Mill causes a real danger of a social and environmental disaster for Lake Baikal and the entire Southern Baikal region, therefore, the problem of developing integrated solutions for dumping the accumulation of lignin-containing waste is especially acute. One of the promising areas for processing this type of waste is the use of natural processes, for example, freezing in winter, temperature detection or self-overgrowth of the occurrence of natural succession. The main aim of the research is to develop an environmentally friendly technology for processing colloidal lignin-containing waste from the pulp and paper industry. Methods: pilot tests at the Solzan industrial site of Baikal Pulp and Paper Mill for freezing lignin-containing wastes and obtaining soils from them by mixing with additives; performing quantitative chemical analysis using the methods of atomic absorption and atomic emission spectrometry, high performance liquid chromatography, toxicological analysis. Results. Pilot tests have shown that after freezing, the colloidal structure of lignin-containing sediments is destroyed with a decrease in volume up to 40 %, humidity up to 60 %, and also with a decrease in toxicity – from the third (moderately hazardous) to the fourth (low hazardous) and fifth class (practically non-hazardous) of hazard of the waste depending on its composition. After freezing, the resulting sludge with the introduction of various additives (CHP ash, sewage treatment plant sludge) can be used as soil ground and fertilizers for reclamation of disturbed lands and crops. Thus, an environmentally friendly technology was developed for processing waste from the pulp and paper industry to obtain soil ground, which is low-energy and does not contain expensive imported equipment.

The purpose of this study is to solve the problem of industrial waste storage. Waste from the production of mineral fertilizers is considered in this study (as an example—phosphogypsum LLC «Industrial group «Phosphorit»). Waste storages on a landfill have a significant negative impact on the environment. This fact has been confirmed by studies of wastewater from the dump (drainage water). Phosphogypsum utilization as a mineral component of an organic-mineral mixture without preliminary purification is the most promising approach. In this case, the joint utilization of lignin sludge as an organic component is required. The absence of excess content of toxic elements and the presence of plant nutrients in the required quantities was established as a result of laboratory studies of soil additive. In addition, the authors noted an increased content of stable strontium in phosphogypsum. Localization of strontium in the soil mixture is ensured by fractional application. Strontium is replaced by covalent calcium when the components are absorbed by the plants. The developed soil mixture should be considered as a single-use organomineral additive with prolonged action. Forestry activities, reclamation of disturbed lands, slopes of highways and landfills of solid municipal waste are promising areas of implementation. [ABSTRACT FROM AUTHOR]