Disposal Technology Research Articles

Recycling of used domestic waste oils: A benign emulsifier-free lubricating material for leather process

The leftover vegetable oils after frying of food at higher temperature is toxic to environment as diminutive of technologies for proper disposal and reuse of waste cooking oil. An highly water soluble and emulsifier-free phosphorylated fatliquor with the emulsion stability of more than 60 min from economically cheap deep fried oils on transesterification with highly biodegradable ecologically innocuous and water soluble Poly (ethylene glycol) with p-Toluene Sulphonic acid followed by phosphorylation produces highly water dispersible and stable material for leather applications. The synthesised phosphorylated fatliquors were ascertained for the lubrication of collagen fibres and fibre splitting of goat skin by SEM analysis. The transesterification has confirmed by FT-IR, fat composition oils, COD, BOD, total solid in spent liquor were analysed. Physical characteristics of leathers were analysed by tensile strength, tear strength, elongation and quality assessments by hand evaluation by experts. Acid, iodine, saponification values, particle size of phosphorylated fatliquors, surface wettability, thermal stability of leathers were analysed and the properties compared. The finding can assist an emulsifier-free lubricating process significantly as currently available leather chemicals.

Advances in the Safe Disposal and Comprehensive Utilization of Spent Carbon Anode From Aluminum Electrolysis: Prospects for Extraction and Application of Carbon Resources From Hazardous Waste

Spent carbon anode (SCA) is a dangerous solid waste that is continuously discharged from the aluminum electrolysis industry and has a large number of valuable resources and a high risk of environmental pollution. Its safe disposal and resource utilization have become a resource and environmental problem that must be solved urgently. Current methods for SCA disposal include flotation, vacuum metallurgy, physical activation, roasting, bubbling fluidized bed combustion, alkali fusion, alkali leaching, and chemical leaching combined with high temperature graphitization. In this paper, the material composition, resource properties, and environmental risks of SCA are discussed. Working principle, treatment process, advantages and disadvantages of the above methods are also briefly described and compared. Results showed that flotation is the safest disposal and comprehensive utilization technology that is suitable for characteristics of SCA raw materials and has the most large-scale application potential. In addition, characteristics of SCA recovery products are correlated to the recycling of aluminum reduction cells. This technology can alleviate the shortage of high-quality petroleum coke resources in China’s carbon material industry and the high cost of raw materials in aluminum electrolysis industry.

Current available treatment technologies for saline wastewater and land-based treatment as an emerging environment-friendly technology: A review.

Different industrial activities such as agro-food processing and manufacturing, leather manufacturing, and paper and pulp production generate highly saline wastewater. Direct discharge of saline wastewater has resulted in pollution of waterbodies by very high magnitudes. Consequently, an enormous number of pollutants such as heavy metals, salts, and organic matter are also released into the environment threatening the survival of human and biota. Saline wastewater also has significant effects on survival of plants, agricultural activities, and groundwater systems. Several treatments and disposal technologies are available for saline wastewater, but the selection of the most appropriate treatment and disposal technology still remains a major challenge with respect to the economic or technical constraints. Considering the sustainable management of saline wastewater, the present review is an attempt to compile the existing and emerging technologies for the treatment of saline wastewater. Among all the individual and hybrid technologies, land-based treatment systems are proven to be the most efficient technologies considering the energy demands, economic, and treatment efficiencies. Likewise, new and sustainable technologies are the need of hour integrating both the treatment and management and the resource recovery factors along with the ultimate goal of the protection in terms of human health and environmental aspect. PRACTITIONER POINTS: Physico-chemical treatment technologies for saline wastewater. Combined/Hybrid technologies for the treatment of saline wastewater. Land-based treatments as the environment friendly and sustainable method for saline wastewater treatment and disposal. Role of phytoremediation in land-based treatment.

Analysis of Basic Physical and Chemical Characteristics of Manganese Slag before and after Solidification and Its Feasibility as Highway Slope.

Manganese slag is a kind of industrial waste produced by electrolytic production of manganese metal. The traditional method of stacking manganese slag not only causes waste of resources, but also produces environmental pollution. Finding harmless, effective, and economical disposal technology of manganese slag has gradually become a research hotspot and difficulty in the field of electrolytic manganese industry and environmental protection. To verify the feasibility of using manganese slag as roadbed material, the basic physical and chemical properties of manganese slag were analyzed based on X-ray diffraction, X-ray fluorescence spectrum, SEM scanning electron microscope, and particle analysis, the basic engineering characteristics of raw materials of manganese slag and solidified manganese slag mixed with quicklime were analyzed through a compaction test and a CBR test. Finally, based on the Monte Carlo method, the stability of a highway slope in the Guizhou Province of China is simulated by the finite element method, considering the spatial variability of manganese slag material strength parameters. The results show that the solidified manganese slag material can be used as highway subgrade material. This study has important reference significance for manganese slag highway construction projects.

Regulation of food waste management in Ukraine and abroad

In the world in general and in Ukraine in particular, there is a catastrophic environmental situation with food waste. The solution to the problem of waste accumulation, the organization of quality control of compliance with legislation in their treatment, the formation of environmental awareness of the population is hampered by the lack of unanimity in defining the essence of waste, industrial waste, waste in the regulatory framework and among scientists. The aim of the work is to study the essence of the definition of food waste in domestic and foreign scientific discussions and regulations in terms of improving the regulation of their treatment in Ukraine. Scientific discussion of domestic and foreign authors on the concept of waste, in particular food, as well as their regulations demonstrate a wide variety of not only definitions but also approaches. This takes into account the legal basis for waste operations, their physical condition and properties, environmental and economic characteristics, the criterion of goal setting, accounting approach and so on. The analysis of the existing classifications of waste stated the absence of a separate category of food waste both in the works of Ukrainian scientists and in domestic regulations, while foreign authors are actively researching this category. According to the results of the study, it is proposed to introduce into the domestic regulatory framework the term "loss of food and food waste" commonly used abroad with the following definition: products (substances) as edible parts of plants and animals produced or collected for human consumption but ultimately not consumed. Critical analysis of domestic environmental legislation in comparison with European allowed to propose the implementation of the Waste Framework Directive, as well as the formation of a hierarchy of waste management priorities: prevention, preparation for reuse, recycling, other types of disposal, elimination as Ukraine's European integration. Areas of further research will be the study of food waste disposal technologies of the modern city.

Upcycling of steel slag for manufacture of Prussian-blue-encapsulated pectin beads and its use for efficient removal of aqueous cesium

Development of innovative technology for solid waste disposal, particularly the synthesis of novel energy and environmental materials via upcycling of solid wastes, is essential for boosting sustainable development in urban areas. In this study, we developed a novel synthesis method for Prussian-blue-encapsulated pectin beads (PB@PD) using Fe and Ca sources in steel slag (SS) and demonstrated its feasibility for the removal of Cs+ via batch and fixed-bed column reactors. Hydrochloric acid (HCl) was used for Fe and Ca dissolution in the SS suspension, and the extracted Fe and Ca were then used for the synthesis of Prussian blue and pectin polymer beads, respectively. The surface characteristics of PB@PD were determined through advanced microscopy and surface analyses, which confirmed the successful formation of a PB crystal structure and well-distributed PB particles in the cross-linked pectin structure. Batch isotherm adsorption experiments conducted using PB@PD revealed that the maximum adsorption capacity of Cs+ was 54.34 mg/g. PB@PD could be recycled up to four times and was very effective for Cs+ adsorption in artificial seawater. Furthermore, we successfully applied PB@PD as a filling material in a fixed-bed column reactor and obtained an effective adsorption capacity (41.75–43.9 mg/g) without any clogging problem during the continuous Cs+ treatment.

Unsaturated mine tailings disposal

Filtered tailings is the disposal technology that is most likely to yield an unsaturated state of the tailings. Such state has important benefits. A dam to contain the mine wastes is no longer needed, the risk of polluting seepage is minimized, and liquefaction of tailings is prevented. Filtering also allows most of the water mixed with the tailings to be recovered and reused in the process. The resulting material can be handled with traditional soil moving equipment to form a stack, for instance. While the idea is simple, the multiple phenomena involved in the tailings unsaturated disposal make up a complex process. The present work is based on a case study, the Casposo Mine filtered tailings disposal facility, located in the central Andes of Argentina. Throughout ten years of operation, a series of field and laboratory studies have been carried out to characterize the phenomena that intervene in the disposal of filtered tailings. Two stages were studied in detail: air drying upon tailings discharge and tailings compression under the weight of the subsequent lifts of the stack. Flocculant agents were found to have an outstanding influence in the tailings behaviour. Because of the multiple influencing factors, the process outcome (namely, the tailings water content and their void ratio) is highly variable. To deal with such variability, projects must include enough redundancy. In this regard, the case study’s incorporation of waste rock layers interspersed between tailings layers was a successful experience.

Thermal decomposition of perfluorinated carboxylic acids: Kinetic model and theoretical requirements for PFAS incineration

Thermal decomposition of high-fluorine content PFAS streams for the disposal of old generations of concentrates of firefighting foams, exhausted ion-exchanged resins and granular activated carbon, constitutes the preferred method for destruction of these materials. This contribution studies the thermal transformation of perfluoropentanoic acid (C4F9C(O)OH, PFPA), as a model PFAS species, in gas-phase reactions over broad ranges of temperature and residence time, which characterise incinerators and cement kilns. Our focus is only on gas-phase reactions, to formulate a gas-phase submodel that, in future, could be used in comprehensive simulation of thermal destruction of PFAS; such comprehensive models will need to comprise fluorine mineralisation on flyash and in clinker material. Our submodel consists of 56 reactions and 45 species, and includes new pathways that cover the initial decomposition channels of PFPA, including those that lead to the formation of the n-C4F9 radical, the abstraction of hydroxyl H by O/H radicals, the fragmentation of the n-C4F9 radical, reactions between HF and perfluoropentanoic acid, as well as between HF and heptafluorobutanoyl fluoride (C3F7COF), and the cyclisation reactions. The model illustrates the formation of a wide spectrum of small CnFm and CnHFm compounds in the temperature window of 800–1500 K, 2 and 25 s residence time in a plug flow reactor, providing theoretical estimates for the operating conditions of PFAS thermal destruction systems. The initiation reactions involve the loss of HF and formation of the transition α-lactone species that converts to C3F7COF, with C4F9C(O)OH completely decomposed at 1020 K for 2 s residence time. At 1500 K, we predict the emission of ꞉CF2 (biradical difluorocarbene), HF, CO2, CO, CF4, C2F6, and C2F4, but at < 1400 K, we note the formation of 1H-nonafluorobutane (C4HF9), phosgene (COF2), and heptafluorobutanoyl fluoride (C3F7COF), with 1-C4F8, 2-C4F8 and C3HF7 persisting to 1500 K. We demonstrate that, the gas-phase pyrolysis processes by themselves convert PFAS to HF and short-chain fluorocarbons, with similar product distribution for short (2 s) and long (25 s) residence times, as long as the treatment temperature exceeds 1500 K. These residence times reflect those encountered in incinerators and cement kilns, respectively. Thermokinetic and mechanistic insights revealed herein shall assist to innovate PFAS thermal disposal technologies, and, from a fundamental perspective, to accelerate research progress in modelling of gas/solid reactions that mineralise PFAS-derived fluorine.

A review on modern and smart technologies for efficient waste disposal and management

In the current scenario, the word waste management holds much importance in every individual's life. Pollution and the generation of vast waste quantities with no proper waste management process have become one of humanity's biggest threats. This review article provides a complete review of the innovative technologies currently employed to handle and dispose of the waste successfully. This work aims to include the different solid, liquid, gaseous, and radioactive waste management processes. The novel and improved plasma gasification concepts, transmutation, incineration, bio-refineries, microbial fuel cells (MFC) have been thoroughly explained. In addition, some new techniques like Mr. Trash Wheel and the Smart bin approach provide much hope of adequately managing waste. The work's novelty lies in adopting several successful methods of various countries for waste disposal and management. To incorporate or improve India'sIndia's same techniques and processes, we have to tackle the ever-increasing waste disposal problems and find economic and eco-friendly ways of waste management.

Synergetic Effects during Co-Pyrolysis of Sheep Manure and Recycled Polyethylene Terephthalate.

Continuous growth in energy demand and plastic waste production are two global emerging issues that require development of clean technologies for energy recovery and solid waste disposal. Co-pyrolysis is an effective thermochemical route for upgrading waste materials to produce energy and value added products. In this study, co-pyrolysis of sheep manure (SM) and recycled polyethylene terephthalate (PET) was studied for the first time in a thermogravimetric analyzer (TGA) in the temperature range of 25–1000 °C with heating rates of 10–30–50 °C min−1 under a nitrogen atmosphere. The synergetic effects of co-pyrolysis of two different waste feedstock were investigated. The kinetic parameters are determined using the Flynn–Wall–Ozawa (FWO) model. The results revealed that the mean values of apparent activation energy for the decomposition of sheep manure into a recycled polyethylene terephthalate blend are determined to be 86.27, 241.53, and 234.51 kJ/mol, respectively. The results of the kinetic study on co-pyrolysis of sheep manure with plastics suggested that co-pyrolysis is a viable technique to produce green energy.

Life cycle assessment of food waste to energy and resources: Centralized and decentralized anaerobic digestion with different downstream biogas utilization

Anaerobic digestion (AD) has been identified as an efficient food waste disposal technology by many researchers. However, a holistic environmental investigation of different AD configurations integrated with different downstream biogas utilization has never been reported. This study, taking Singapore as an example, compared the sustainability of business-as-usual technology, i.e., incineration, to centralized and decentralized AD with different biogas applications: electricity generation, cooking fuel, and transportation fuel. The results showed that AD scenarios were generally preferable compared to incineration since environmental benefits were observed in seven to fourteen categories for AD scenarios but only four categories for incineration. The decentralized AD with biogas as cooking fuel (Sc_DADcook) achieved the highest environmental benefit in global warming potential (GWP, −238.4 kg CO2 eq./FU) and fossil fuel depletion potential (FFP, −93.5 kg oil eq./FU) among all the analysed scenarios, followed by centralized AD with biogas as transportation fuel (Sc_CADtran). The sensitivity analysis of the different electricity substitution showed that Sc_DADcook and Sc_CADtran lost their advantages when coal-dominated electricity was used, while biogas for electricity generation became favourable with higher environmental savings up to 280% and 150% in GWP and FFP, respectively. Besides, maximizing the methane yield and minimizing the FW collection radius were also identified as important measures to improve the overall environmental performance. Finally, the scenario analysis of different biogas upgrading technologies demonstrated the GWP advantage by membrane separation and benefits in other categories by high pressure water scrubbing. However, biological upgrading needs further optimization particularly of the H2 source associated emissions.

Energy, environment and economy assessment of medical waste disposal technologies in China

Medical waste (MW) has exploded since the COVID-19 pandemic and aroused great concern to MW disposal. Meanwhile, the energy recovery for MW disposal is necessary due to high heat value of MW. Harmless disposal of MW with economically and environmentally sustainable technologies along with higher energy recovery is urgently required, and their energy recovery efficiencies and environmental impacts reduction due to energy recovery are key issues. In this study, five MW disposal technologies, i.e. rotary kiln incineration, pyrolysis incineration, plasma melting, steam sterilization and microwave sterilization, were evaluated and compared via energy recovery analysis (ERA), life cycle assessment (LCA), and life cycle costing (LCC) methods. Furthermore, three MW incineration technologies with further energy recovery and two sterilization followed by co-incineration technologies were analyzed to explore their improvement potential of energy recovery and environment benefits via scenario analysis. ERA results reveal that the energy recovery efficiencies of “steam and microwave sterilization + incineration” are the highest (≥83.4%), while that of the plasma melting is the lowest (19.2%). LCA results show that “microwave sterilization + landfill” outperforms others while the plasma melting exhibits the worst, electricity is the most significant contributor to the environmental impacts of five technologies. Scenario analysis shows that the overall environmental impact of all technologies reduced by at least 45% after further heat utilization. LCC results demonstrate that pyrolysis incineration delivers the lowest economic cost, while plasma melting is the highest. Co-incineration of sterilized MW and municipal solid waste could be recommended.

Control of Fine Cutting Chips to Improve the Processing Environment in CFRP Drilling

Carbon fiber reinforced plastic (CFRP) is increasingly used in aerospace, automobile, and other industries. With the improvement of carbon fiber reinforced thermoplastic molding technology using thermoplastic resin, it is expected that the applications of CFRP will be expand further. Because of the following issues, CFRP is known as a difficult-to-cut material. i) Machining CFRP is difficult. ii) Its finished surface deteriorates due to delamination and uncut fiber. iii) It has a shortened tool life due to severe tool wear. In addition to these issues, we has been problem presentation of fine cutting chips generated by machining. Because these fine cutting chips may scatter in the atmosphere and adversely affect the human body and machine tools, we have established a chip disposal technology that suppresses these issues to improve the processing environment. A previous study reported that shape of the tool edge is responsible in suppressing the generation of fine cutting chips. Here, we experimentally investigated the effects of tool edge shapes on the chip collection rate and tool life. An attempt was made to determine whether the same effect can be obtained by using the outside dust-collection method which is known that the dust collection efficiency is low. We revealed that the chip collection rate increases if a tool that suppresses the generation of fine cutting chips is used instead of a conventional tool; furthermore, the tool life is insensitive to coating. In contrast, a comparison of our results with previous findings indicates that the tool with a sharpened cutting edge has a longer tool life than the conventional twist drill with honing. A high cutting chip collection rate was obtained, even with the outside dust-collection method, which led to an improvement in the working environment.

A Review on Smart Waste Collection and Disposal System

The main cause for land pollution is overflow of garbage. It makes insanitary condition for the encompassing individuals and cause ailment. This paper focuses on the review of various existing techniques available for garbage monitoring. In this article, survey about the waste monitoring methods, garbage disposal techniques and technologies utilized for developing a system to deal with waste management are presented. Finally, an efficient system is proposed along with waste disposal method that can be used in future for achieving better performance and cost effectiveness.

Selection of healthcare waste disposal firms using a multi-method approach

The aim of this study is to propose a hybrid multi criteria decision making model with a linear programming (LP) model to tackle the issue of safe disposal of hazardous and infectious healthcare waste. For this, ten criteria in this study have been identified from literature and field surveys which are modelled using Decision making trial and evaluation (DEMATEL) and Analytic network process (ANP) methods to select the best disposal firm i.e. single sourcing for a hospital. We found that Experience of the firm, Technology for disposal, and Waste collection infrastructure acts as the most vital criteria in selecting a healthcare waste disposal firm for single sourcing. Furthermore, to optimize the total value of disposal and mitigating the risk involved in disposing waste through single sourcing; the LP model considering constraints such as waste lose constraint and waste processing constraint etc. Is solved for multiple sourcing using Lingo 18.0. The solution to LP results into allocation of 500, 500, and 1000 (kg/day) disposables to healthcare waste disposal firms D1, D2 and D3, respectively. The multi-method approach proposed in this study helps the hospital management in selecting economically, socially, and environmentally sustainable healthcare waste disposal firm.

Chromium speciation in tannery sludge residues after different thermal decomposition processes

Thermal decomposition is a promising technology for tannery sludge disposal, as through thermal decomposition, the energy in tannery sludge could be recovered, and the abundant harmful metal chromium (Cr) could be fixed in the solid residues, which might be recycled as the chromium-rich mineral for further use. In order to provide objective evaluation on the various thermal decomposition technologies for tannery sludge disposal from safety perspective, in this study, different thermal decomposition processes of tannery sludge in typical reactors were simulated on a bench-scale equipment in laboratory, and the transformation characteristics of Cr species in tannery sludge during the processes were systematically investigated. Through characterization of the solid products of decomposition, only Cr (III) species of Cr2O3 and MgCr2O4 were determined in the pyrolysis product, while both Cr (III) species of Cr2O3 and Cr (VI) species of CaCrO4 were detected in the incineration product. For the processes of simulating gasification, when the final stage was combustion, Cr (III) species of Cr2O3 and MgCr2O4 and Cr (VI) species of CaCrO4 were observed, while when the final stage was reduction, only Cr (III) species of Cr2O3, MgCr2O4 and CaCr2O4 were observed. It was found that the Cr (III) species of MgCr2O4 generated in the pyrolysis stage has high stability and is difficult to be oxidized in the combustion stage, while Cr (VI) species of CaCrO4 produced in the combustion stage can be removed in the subsequent reduction stage. Based on the results, among the various thermal decomposition technologies to dispose of tannery sludge, pyrolysis is the safest, while incineration presents a huge risk. The adoption of downdraft gasifier is safer than that of updraft gasifier. Therefore, employing pyrolysis or downdraft gasification technology to dispose of tannery sludge is expected to fix Cr in the form of non-toxic Cr (III) in the solid residue, and then reuse it as tannery agent, so as to achieve the goal of cleaner production.

Multi-criteria analysis of municipal solid waste treatment technologies to support decision-making in Kisumu, Kenya

The directive to close the dumpsite in Kisumu, Kenya has made the search for alternative solid waste treatment and disposal technologies urgent. The aim of this research is to support the decision-making process by analyzing multiple socioeconomic and environmental parameters of salient solid waste treatment options. We used multi-criteria analysis to assess and compare anaerobic digestion, sanitary landfill, bioreactor landfill, and incineration. Informed by field observations and interviews, the chosen assessment criteria were economic costs, electricity generation, GHG emissions, land footprint, air pollution, soil and water contamination, and compatibility with recycling efforts. A literature review yielded quantitative and qualitative data that supported the analysis and the ranking of solutions according to performance in each criterion. Our analysis shows that anaerobic digestion is a suitable solution for Kisumu, due to its reduced environmental impacts, production of electricity and fertilizer, suitability to treat the large organic waste stream generated in the city, and compatibility with independent recycling activities. Landfilling represents a cheap solution; however, previous failed initiatives indicate that finding available land close to main waste generators is a challenge. Incineration is costly and requires advanced air quality control equipment and high combustibility of incoming waste, which is not the case for Kisumu, where over 60% of waste stream is organic/wet. Our results and recommendations are targeted for the Kisumu case, but they can be relevant for researchers and policymakers elsewhere, especially in low- and middle-income cities facing similar challenges.

PROCESSING AND RECYCLING OF PHOTOVOLTAIC SOLAR PANELS

The steady tendency of increasing the installed capacity of solar power plants, which is accompanied by the gradual accumulation of solar panel waste, is analyzed. The main factors of negative impact on the environment and directly on human health from the production of solar photovoltaic panels and waste of these panels are identified. The scenarios of solar photovoltaic panels waste accumulation are analyzed, the specifics of waste generation and accumulation in the present and in the future are characterized. Taking into account the average service life of solar photovoltaic panels in 25 years, it is determined that the amount of waste will increase significantly in the period of 2030…2035, reaching a peak between 2040 and 2050. The type and composition of photovoltaic panels, which determine the essence of waste processing technology, are characterized. It is defined that today most research on waste recycling of solar photovoltaic panels focuses on the first generation of modules, which is associated with the scale of operation of these panels and sales markets. It was found that at present, the production of solar photovoltaic panels, which consumes primary natural materials, is characterized by nature intensity, and direct waste processing cannot meet the needs of the photovoltaic modules production. The objective necessity of carrying out large-scale extraction of minerals and use of precious metals before the period of highly efficient processing of waste solar photovoltaic panels, which would meet the demands of production, is substantiated. Modern tendencies in technological researches and developments of secondary processing of photovoltaic modules are considered. It is determined that as the volume of solar photovoltaic panels production and waste generation increases, the requirements for ensuring the environmental efficiency of waste processing and disposal technologies should be more stringent. This involves increasing the recycling degree of the waste’s main components, starting from 80…90 % and to the highest possible level. It is determined that at the same time with this tendency, it is expedient to develop technologies for recycling of non-recyclable parts of waste at present.

Effect of sewage sludge ash contents on the performance of thermo-sensitive hydrogel as draw agent for forward osmosis application

In this study, a novel and environmentally friendly technology for sludge incineration ash disposal was developed. We proposed to enhance the performance of thermo-sensitive hydrogel as draw agent for forward osmosis (FO) application by loading sewage sludge ash (SSA). The effect of SSA contents on the swelling and deswelling properties and FO performance of the hydrogels was evaluated. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and diffusion model were applied to characterize a series of hydrogels with various SSA contents (0–4.5 wt%). The results showed that as the SSA increased, the swelling ratio of hydrogel and the water flux of SSA-hydrogel-based FO increased initially and then declined. This was due to the combined effects of hydrogen bonding and high-density crosslinking within the hydrogels. In addition, the water diffusion mechanism of all hydrogels was super Case II diffusion type. Furthermore, the SSA-loaded hydrogels not only had excellent swelling property but also exhibited good deswelling performance (water recovery ratios of them were almost 90% at 60 °C water bath for 5 min). Moreover, all hydrogels in this study showed promising reusability with almost no flux drop in four consecutive FO permeation-regeneration cycles.

ИССЛЕДОВАНИЕ МЕТОДОВ ПОДГОТОВКИ ОРГАНОСОДЕРЖАЩИХ СЕЛЬСКОХОЗЯЙСТВЕННЫХ ОТХОДОВ ДЛЯ ИХ ДАЛЬНЕЙШЕЙ ПЕРЕРАБОТКИ В СВЕРХКРИТИЧЕСКОЙ ВОДНОЙ СРЕДЕ

The problem of waste disposal is always acute in all areas of production activity, especially for the agro-industrial complex. Supercritical water oxidation is the most environmentally friendly method for processing organic waste and persistent organic pollutants. In the process of recycling and disposal, along with the harmfulness, one of the main indicators is the initial state of the waste and its suitability for different disposal technologies. (Research purpose) The research purpose is in choosing and justifying the most energy-efficient method of grinding, taking into account the fact that the organ-containing waste under study (buckwheat husk, sunflower, rice) is soft, elastic and fibrous materials. (Materials and methods) The crushing of organic waste to prepare it for further processing was carried out by different methods in roller, ball, knife and colloid mills. A set of sieves with square cells according to GOST 2715-75, a drying cabinet SHS-80-01 SPU, analytical scales Acculab ALC-210d4 (weighing error of no more than 0.5 percent of the sample weight) were used to evaluate the fractional composition of the obtained material. (Results and discussion) At a concentration of 100 grams of husk per 1 liter of water after 30 minutes of wet grinding, the passage of particles through the sieve is 87.1 percent. The article presents the advantage of wet grinding in a knife mill, reveals mathematical dependencies that allow predicting the grinding process to obtain the product of the required dispersion. (Conclusions) The grinding of organ-containing waste in a knife mill by wet grinding is the most optimal technology for preparing this waste for further processing in a supercritical water environment. The obtained mathematical dependencies allow us to predict the grinding process.