Peculiarities of biogenic elements migration in case of complex utilization of bioorganic component of municipal solid waste

Finding solutions to the problem of municipal solid waste management is impossible without involvement in the waste management system of the largest group of wastes – bioorganic waste, which form up to 60% of the municipal solid waste total mass. The aim of the article is to analyze the redistribution of biogenic elements subject to implementation of the Concept of solid municipal waste management by OSENU and subsequent utilization of bioorganic waste flow. Research methods include mass balance and equations of methane generation. The article presents the results of research on the biogenic elements migration in case of complex utilization of bioorganic component of municipal solid waste. The study shows that processing of easy-decomposed organic waste into a gaseous fermentation product and biomineral fertilizer allows full involvement of biogenic elements in natural cycles. The processed solid products present an additional source of organic matter and biogenic elements needed by soil. In the event of humus and nutrients shortage in soil the retrieved-from-waste fertilizer becomes an important secondary resource, containing up to 65% carbon and almost 100% nitrogen, phosphorus and potassium. The rest of carbon is released with biogas and is eventually involved in natural cycles. Burial of such waste results in localization of biogenic elements in a landfill's body and gradual release of carbon with the products of destruction (27% over 50 years). All this data indicate the need for efficient use of such waste resource potential which is possible in case of easy-decomposed organic waste separation at the beginning of the municipal solid waste life cycle. Combustion releases only carbon in the form of carbon dioxide, the rest remains in ash. However, complex utilization of easy-decomposed organic waste ensures complete return of biogenic elements to the environment. Reuse of secondary raw materials in the form of paper and textile waste minimizes involvement in economic turnover of carbon from natural sources.

Processing of waste slag of non-ferrous metallurgy for the purpose of its complex utilization as a secondary mineral raw material

This article provides an overview of the methods of processing slag from welting is given, different approaches and attempts of scientists from a number of countries aimed at processing such slags are considered. In the course of the review it was found that a huge number of the following methods and methods of processing from waelz slag, there is not a single option that has sufficient complexity of processing, and that at the moment are in the dumps toxins from waelz never found its use as a secondary raw material. The elemental chemical composition of the slag from welting, which is represented by compounds of calcium, silicon, iron, aluminum, carbon and heavy nonferrous metals in the form of zinc and lead, is determined. Thus, it is established that for many years, the slags from waelz that have not found their application and are in the dump at the moment continue to have a polluting effect on the environment. Ill. 1. Ref. 63.

Development of the system of energy and resource saving during the operation of the gas pumping unit

The object of research is the fuel gas system of a gas turbine engine. The study of the use of secondary energy resources of the gas-pumping unit at the compressor station of the main pipeline has been carried out. The work of a gas turbine engine, including the work of the fuel gas system, is considered. The main drawback of the fuel gas system is revealed – ineffective use of excess gas pressure. An informational analysis of the options that eliminate the identified drawback is carried out. It is shown that in order to eliminate the disadvantage, it is advisable to use a turbo-expander at the compressor station to utilize the excess pressure of the fuel gas. It is also shown that the operation of a fuel gas turboexpander to drive an additional air compressor as part of a gas turbine engine is impractical. An expander-generator set with the generation of additional electricity at the compressor station is recommended for use. Modeling the operation of the utilization system made it possible to recommend constructive proposals for its improvement. A schematic diagram of a system for the complex utilization of excess pressure of fuel gas and heat of combustion products from the operation of a gas turbine engine is proposed. The system of complex utilization includes parts-generator unit, heat exchanger for cooling process gas and heat exchanger for firing gas. Regenerative heating of fuel gas up to 250 °С reduces energy consumption for heating it up to the ignition temperature. A model of a robot installation of the type GPU 16/56-1.44 (Ukraine) is carried out. It is determined that when a component engine of the J-59 (Ukraine) type with a shaft power of 16 MW operates, it is possible to additionally receive 102 kW of electricity and save 64 m3/h of fuel gas. It is revealed that the subcooling of the process gas does not play a significant role in reducing energy consumption during its transportation. It is recommended to use the process gas to heat the cold fuel gas stream downstream of the turboexpander to positive temperatures. The integrated utilization system is not a simple connection of an expander-generator set and two heat exchangers along the flow of the fuel gas. As a result of its operation, a significant reduction in the consumption of fuel gas and electricity is achieved. The disadvantages that hinder the implementation of a comprehensive disposal system are identified. This is the use of equipment for generating electricity at a compressor station. It is uncharacteristic for the operation of the station and requires additional qualifications in service. It is also required that the characteristics of industrial expander-generator sets correspond to the fuel gas consumption of a gas turbine engine.

The Concept of Dumping Nickel Slag Processing with Preliminary Extraction of Metals

The present study considers various technological approaches to the processes of complex utilization of nickel slags with preliminary additional extraction of non-ferrous metals, iron, and ways of utilization of the obtained gangue. The valuable components are often produced from waste using the mineral acids or mixtures; the metals are extracted from acid solutions in a free form or in the form of compounds using electrochemical or chemical methods. Slag dumps have a heterogeneous structure and mineralization; the zone distribution of slag is clearly defined due to different cooling and solidification rates. The slag composition is mostly represented by dense low-porous varieties consisting of dark brown glass. The porous slag fragments are secondary. The third texture diversity in the composition of slag is represented by nodular and kidney-shaped particles. The diversity and size of the ore minerals is directly connected with the distribution of pores in slag. The major ways for utilization of nickel industrial waste are pyro-metallurgical and hydrometallurgical methods. In addition, each of the methods is usually preceded by the stage of mechanical preparation of the raw materials, where the techno-genic waste is crushed.

ALUMINOSILICATES FROM RICE STRAW: OBTAINING AND SORPTION PROPERTIES

In order to solve the problem of complex utilization of rice straw – waste of rice production – the task was to obtain from vegetable silicon-containing raw materials samples of aluminosilicates that are promising for use as highly efficient sorbents. A series of sodium aluminosilicate samples were synthesized from alkaline hydrolysates of rice straw of various strains of Far Eastern breeding, the effect of synthesis conditions on the properties of the final product was investigated. The chemical and phase composition of the samples were determined, the particle morphology was observed by scanning electron microscopy, the specific surface area was measured, the IR spectra were recorded, the thermal properties were studied, the limits of thermal stability were determined, and the products of thermal transformations were identified. The acid-base properties of the surface were investigated by the pH-metry method and the Hammett indicator method, and the distribution of active centers was determined. The dependence of the sorption capacity of the obtained aluminosilicates on rice varieties and the conditions of the extraction of silicon from the straw (the duration of alkaline hydrolysis) was established on model aqueous solutions of methylene blue. The results expand the possibilities of comprehensive utilization of agricultural wastes with obtaining valuable products and deepen knowledge about the processing biogenic silicon-containing raw materials and the sorption mechanisms of organic pollutants on aluminosilicate materials.

Method of Utilization of the Spent Vanadium Catalyst

A spent vanadium catalyst, from the plant of metallurgical type, was leached in a potassium hydroxide solution to recover vanadium. The effect of time, temperature, concentration of basic, catalyst particle size and phase ratio was studied. The results showed that for a 160-750 μm catalyst leached for 4 h at 313.15 K in the presence of 10% potassium hydroxide solution at a liquid: solid ratio of 20:1, the extent of leaching of V was about 87%. Additionally, separation of vanadium from such a solution was investigated by the ion exchange method. Two types of polymer strongly basic ion exchangers were used. The ion exchange tests indicate that vanadium were loaded from the post-leaching solution with high effi ciency. On this basis a fl owsheet for the proposed process of a complex utilization of the spent vanadium catalyst is presented.