## 1 Introduction
Due to the active development of chemical science in the direction of the creation of novel nanomaterials and nanostructured catalysts, a major breakthrough has recently been made in the development of chemical catalysis, which provides, mainly owing to oxidative reactions, effective pretreatment of hydrocarbon-containing wastes. Heterogeneous catalysts in the form of nanoparticles (NPs) are usually characterized by a high ratio of their surface area to the volume they occupy. This leads to their higher efficiency of action with the simultaneous possibility of separation from the reaction medium after application [15; 16]. This review presents an analysis of current trends in the development of nanostructured catalysts and applications in the conversion of hydrocarbon-containing wastes. The review is also aimed at analyzing the probable combination of chemical catalysis with biocatalysts (BCs) for deeper and more efficient processing of hydrocarbon-containing wastes (Figure 1). The latest achievements (2017-2023) in the field of advanced oxidation processes using NCs and NComs developed for the decomposition of hydrocarbon pollutants were used as the main objects of analysis in this review. Possible options for biocatalytic treatment of various hydrocarbon pollutants using homogeneous or immobilized BCs (including biofilms) and combinations of various BCs with nanomaterials were also compared in this review. Some mechanisms associated with the manifestation of a synergistic effect in the action of various catalysts were especially emphasized. Nanocatalysts and Nanocomposites in Pretreatment Processes from Carbon-Containing Real or Model Waste and Contaminated Wastewater  
Today, the main directions of chemical degradation of hydrocarbon-containing wastes using nanocatalysts (NCs) and catalytically active nanocomposites (NComs) are associated with advanced oxidation processes (AOPs) (Table 1) [15; 16; 17; 18; 19; 20; 21; 22; 23] and correspond to general trends in the development of processes related to wastewater treatment [33]. AOPs are based on the oxidation of components of purified media under the action of radicals, such as hydroxyl (\(\bullet\)OH), superoxide (\(\bullet\)O\({}_{2}\)\({}^{-}\)) and sulfates radicals (SO\({}_{4}\)\({}^{-}\)\(\bullet\)). Among the varieties of AOPs used for wastewater and soil treatment, there are photocatalytic oxidation, Fenton-like oxidation, electrochemical oxidation, wet air oxidation, ozonation, and oxidation with H\({}_{2}\)O\({}_{2}\), ultrasound, microwave or gamma irradiation activation, sulfate radical-based advanced oxidation processes and their combinations [33]. Due to the development and application of NCs and NComs in the implementation of AOPs in the processes of degradation of hydrocarbon pollutants, significant results have been achieved in almost all of these areas in recent years (Table 1). The prospects of the practical application of NCs are increased due to the possibility of their repeated use (3-10 cycles) [15; 16]. The method of photocatalytic oxidation has become the most widespread due to the availability of reagents, high efficiency, environmental friendliness and relatively low energy consumption compared to other physico-chemical methods. Among the NCS for photooxidation are TiO\({}_{2}\), ZnO, ZrO\({}_{2}\), \(\alpha\)-Fe\({}_{2}\)O\({}_{3}\), MgO\({}_{3}\), CeO\({}_{2}\), SnO\({}_{2}\), WO\({}_{3}\), CuS, ZnS, WS\({}_{2}\), CdSe, CdS, MgS\({}_{2}\), bi-based materials (composite Bi\({}_{2}\)WO\({}_{6}\)/CN and ribbon-like oxygen-rich Bi\({}_{2}\)O\({}_{17}\)Cl\({}_{2}\)) and Ag\({}_{3}\)PO\({}_{4}\) in combination with metal oxides (Mn\({}_{3}\)O\({}_{4}\)/MnO\({}_{2}\)-Ag\({}_{3}\)PO\({}_{4}\) and Ag\({}_{3}\)PO\({}_{4}\)@Fe\({}_{3}\)O\({}_{4}\)) [34; 35; 36]. In a number of processes related to the heterogeneous photocatalytic purification of water and soil from organic pollutants, NCs from the mentioned list are also used [15; 17; 21; 22; 23; 25; 31; 32].