Moscow State University of Engineering Ecology - the center of environmental science in Russia.
Proceedings of international conferences
1. Ecological problems of megacities. V.Yu. Ryzhnev and others. "Russian Ecoanalytical Technologies". It is reported about the creation of Russian ecoanalytical technologies based on domestic analytical instrumentation, which provides a reduction in capital costs by 8 times, operating costs - by 12 times, an increase in laboratory productivity by 3.5 - 4 times while reducing the cost of a unit of chemical analysis by 2.5 - 3 times. A.Z.Razyanov and others "Ecological problems of megacities and the possibility of control systems for atmospheric pollution and industrial emissions." The results of long-term studies of atmospheric pollution and emissions from industrial enterprises in Moscow with the involvement of accredited environmental analytical centers are presented. The high efficiency of mobile facilities - mobile laboratories "Kema" (Netherlands) and "Thermo Euviromental Instruments Inc." (USA). It is shown that a modern control system should provide a reasonable choice of criteria for making managerial decisions. A.N. Chumakov et al. The Scarabey project implements self-sustaining industrial processing of waste into marketable products and energy in the regions of Russia. The combination of domestic and foreign technologies for waste processing and landfill reclamation guarantees the absence of harmful emissions and eliminates the deposition of waste at landfills. Details of the project for the Moscow region were considered. M.Yu.Susyaeva "Technical and economic problems of drinking water purification." It is believed that when treating low-turbid waters by contact coagulation, it is advisable to use the domestic cationic flocculant Akromidan-LK in combination with a deficient dose of coagulant. This will reduce the consumption of coagulant by 30 - 50%, reduce the concentration of aluminum in water, increase the duration of the filter cycle on contact clarifiers by 40 - 60%, reduce the corrosiveness of water and improve the technical and economic performance of treatment facilities. V.M. Volodin and others "Application of neural networks for forecasting in tasks of ecological monitoring". It is proposed to use neural networks to create a predictive environmental monitoring system in the city. The system can play the role of a "consultant", giving out its "vision" of the development of the ecological situation. The current concentrations and weather conditions are fed to the input of the neural network, and the neural network outputs the predicted change in the concentrations of harmful substances. I.N.Dorokhov and others."Ecological economics and sustainable development. "Ecological economics is an alternative direction in economics, designed to take into account and reflect the really existing vital ecological and economic ties. It does not oppose economic growth, but only indicates that growth cannot be predicted by purely economic models that do not take into account the flow of energy and materials . AT
In accordance with the United Nations Development Program, the sustainability of society is achieved when it: 1. Preserves life-supporting ecosystems and biodiversity; 2. ensures the sustainability of the use of renewable resources while minimizing the consumption of non-renewable resources; 3.functions within the bearing capacity of life-supporting ecosystems. B.G.Kalashnikov and others. "Integrated water purification during vehicle washing". In the proposed hardware-technological scheme, contaminated water passes through a sand trap, a hydrocyclone with a bunker, where solid inclusions are washed from oil products with the help of a cleaning agent, then a flotator to separate the bulk of oil products. Purification from fine and dissolved organic contaminants and heavy metal ions takes place in a galvanic coagulator. E.T. Klimenko and others. "Analysis of the distribution of nitrogen oxide concentrations in the territory of a large industrial city." The analysis was carried out according to the OND-86 methodology based on data on emissions from 28 district and 19 quarterly thermal power plants. A file of annual weather conditions was used as meteorological data, which is a discrete version of the probability distribution of meteorological parameters. An array of annual fields of nitrogen oxide concentrations in the city was obtained. E.V.Yaroshevsky and others. "Application of neural calculators of logical functions in environmental monitoring systems."
2.Technique and technology for the protection of air, water basins and soils. V.A.Kernerman and others "Development of an automobile neutralizer based on its mathematical model". A dynamic model of the process of neutralizing exhaust gases in the converter has been developed, which describes the process of "ignition" of the catalyst surface during start-up and the attenuation of the catalytic process. The model can be used to simulate non-stationary processes of carbon monoxide and hydrocarbon oxidation, as well as the reduction of nitrogen oxides in a block catalyst of an automobile converter. TV Druzhinina et al. "Sorption of heavy metals by chemisorption fibers." Modified fibers with nitrogen- and sulfur-containing active groups were used as sorbents. Amination of grafted fiber chains was carried out with polyethylenepolyamine in order to obtain sorbents capable of complex formation reactions. Sorption of copper by fibers provides a 100% degree of extraction from dilute solutions, and selectivity to copper ions was found in the case of solutions also containing cobalt and nickel. M.V. Arkind et al. "Adequate qualimetry of the environmental safety of the technical object." An alternative system for monitoring the state of the environment in terms of the viability of an organism or population exposed to a harmful factor is proposed. T.N. Burdeynaya and others "Purification of industrial gas emissions from nitrogen oxides on new mechano-chemical catalysts." It is proposed to carry out the activation of catalysts by joint grinding of the components at the optimum load and grinding time. A shift in the temperature maximum of the selective reduction of nitric oxide by propane to lower temperatures was observed. Mechanochemical samples of catalysts also show high activity in the reduction of nitric oxide with carbon monoxide in the presence of oxygen. O.B. Butusov and others. "Fuzzy dose-effect modeling of the dynamics of the natural environment in the area of industrial sources of chemical pollution." An information technology has been developed for building dose-effect models of the dynamics of natural systems, including the following steps: multi-attribute dose analysis, fuzzy multi-attribute analysis of the effect, classification of effect indicators based on fuzzy binary relations, construction of group integral effect indices, fuzzy GMOD for approximating dose derivatives. AI Dzisyak and others. "Environmentally friendly technology of natural gas combustion with the use of a catalyst". A method has been developed for burning methane using a catalyst, which provides an ultra-low content of nitrogen oxides. The computational experiment was carried out using a kinetic model including 196 reactions between 32 reagents (molecules, atoms, radicals).
At temperatures below 1400 K, the content of NO x<10 -5 м.д. и CO < 10 -7 м.д., при этом соотношение воздух-метан составляет ~2. А.А.Игнатов и др."Компьютерные комплексы технико-экономического анализа проектов инженерной защиты природных сред". Для обоснования условий технико-экономической эффективности мероприятий по защите природных сред разработаны комплексы взаимосвязанных критериев технической и экономической оценки проектов инженерной защиты. В качестве примера демонстрируется комплекс проектирования работ при радиационном обследовании территории, загрязненной аварийным выбросом радионуклидов. Д.А.Казенин и др."Моделирование воздействия источника загрязнения в водоносном горизонте". Сделана попытка смоделировать возможное воздействие помещенного в водоносный горизонт источника химического, биологического или радиационного загрязнения в виде цилиндрического тела с постоянной концентрацией загрязнения на его поверхности. Задача определения полного потока загрязнения в окружающую среду в условиях стационарного обтекания и ширины зоны в фильтрационной среде за телом, в пределах которой концентрация загрязнений меньше нормы, сведена к решению простейшего параболического уравнения с граничным условием первого рода. В.Г.Калыгин и др."Химико-технологические системы подготовки вторичного использования отходов и продукции силикатных производств". Выявлены приоритетные направления экобиозащитных технологий вторичного использования стеклобоя и стекловолокнистых материалов (в 2000 году в Москве 160 тыс.т.): эндо- экзотермический и механохимический способы переработки. При этом цвет и химический состав не являются ограничительными признаками. П.С.Новиков и др."Эквивалентная электрическая схема озонатора на барьерном разряде." Разработана электрическая модель барьерного разряда для последующего компьютерного анализа. С использованием программ моделирования аналого-цифровых устройств Micro CAP6 по модели рассчитаны электрические характеристики озонаторов различных конструкций. Ю.Г.Пикулин и др. "Обезвоживание нефтесодержащего осадка на барабанных вакуум-фильтрах". Исследования способствовали выбору типа фильтровальной ткани для конкретного оборудования, показали возможность увеличения производительности вакуум-фильтра, позволили определить оптимальные концентрации реагентов, добавляемых перед фильтрацией, показали целесообразность предварительной обработки сточных вод перед фильтрацией с целью удаления нефтепродуктов,в частности, из твердой фазы, аккумулирующей их на своей поверхности. М.Г.Шмелев и др. "Центробежный комбинированный пылеуловитель." Предлагают высокоэффективный аппарат для очистки газовоздушных выбросов, который представляет альтернативу известным системам, состоящим из отдельных аппаратов сухой и мокрой очистки. Высокая эффективность сочетается с низким уровнем энергозатрат и малыми габаритами. Степень очистки от частиц со средним медианным диаметром 10 мкм составляет 98%.
3. Environmental problems of chemical and related industries. D.A. Baranov et al. "Development of an installation for capturing exhaust gases from hydrocarbons". The developed installation uses: adsorption of hydrocarbon vapors from a vapor-air mixture in an adsorption column at a temperature of -15 - -20 degrees, desorption with separation of hydrocarbons and return of the adsorbent. New highly efficient horizontal adsorption devices and special heat exchangers have made it possible to reduce the size, metal consumption and cost. The dimensions of the installation for an "average" gas station do not exceed 1.5x1.0x1.2 m. V.V. Ivanov et al. The results of the activities of the State Unitary Enterprise "Promotkhody" in collecting and neutralizing toxic waste at Moscow enterprises with the production of a number of marketable products are considered. This made it possible not to raise prices for waste collection and to introduce a system of benefits for enterprises that deliver large volumes of waste. A.A. Abrosimov and others. "Ecological problems of oil refining production." A methodology has been developed for an integrated approach to solving the problem of environmental safety, including the following steps: environmental hazard analysis and risk assessment of a modern refinery; development of methods for increasing the level of production safety based on the improvement of technological processes and the reconstruction of equipment; organization of production of new fuels with improved characteristics; improvement of the automated control system for production, technological processes and development of a system for managing the quality of the environment and environmental safety. O.N.Kulish et al. "New technology for cleaning industrial gas emissions from nitrogen oxides. "A homogeneous-heterogeneous process has been developed, which is a combination of non-catalytic high-temperature and catalytic low-temperature reduction of nitrogen oxides by products of thermal decomposition of urea. Efficiency in any mode of operation of the thermal unit is close to 100%. The process can be applied to all units using fossil fuels. T.V. Savitskaya et al. "Creation of environmentally friendly and safe chemical production using new information technologies. "To improve the safety of chemical production, it is proposed to use a new type of intelligent automated systems - integrated automated control systems (IACS), combining information and modeling and control systems, software systems and technical means for collecting and transmitting data based on local area networks. The information and software of the two proposed IACS are implemented in the form of two software packages and used to analyze and assess the environmental risk of MosNPZ and Novomoskovsk joint-stock company "Azot." A.Yu.Belyankin et al. "Continuous process of pyridine production waste processing into lower alkylpyridines and pyridine on a heterogeneous catalyst." A hydrodealkylation catalyst has been created for the processing of pyridine production wastes into lower alkylpyridines and pyridine with increased selectivity and yield. At 300 - 400 degrees. and 1 - 10 atm. "pyridine resin" containing 70 wt. % alkylpyridines with a molecular weight of more than 140, is converted with a selectivity of up to 70% and a conversion of ~ 80%. The main products are methyl-, dimethyl- and methylethylpyridines. The catalyst works 20 - 50 hours and withstands more than 20 thermal regeneration cycles. I.N.Dorokhov and others. "System approach to the creation of an environmentally friendly galvanic production." Based on the results of the analysis of the current state of the problem of creating an environmentally friendly galvanic production (GP), a generalized functional-operator scheme of a rational variant of the GP is proposed that meets modern requirements for environmental safety and efficiency.
Modeling has shown that the rational organization of the HP itself, and not the improvement of the treatment of already formed effluents, is a promising direction in the creation of environmentally friendly HP. V.A. Listov et al. "Approach to designing systems for remote collection and processing of information for tasks of environmental monitoring and management." Approaches to solving the problem of automated collection and processing of information for the tasks of environmental monitoring and control of chemical and technological processes are formulated. VN Novozhilov and others. "Ascending forward flow in pipes of variable diameter." An apparatus for liquid-gas exchange processes with a height-changing pipe cross-sectional size, consisting of three (or more) sections, is proposed. In the first and the last one, the mode of stable upward cocurrent flow is carried out, on average, the gas velocity is in the flooding region. In such an apparatus, the hydrodynamic regime is characterized by moderate pulsations and can be maintained for as long as desired. MGKhametova "Ecological safety of processes of extrusion processing of polymers." A method has been developed for calculating safe technological regimes for the extrusion processing of polymers, which makes it possible to obtain the required quality at high equipment productivity in environmentally friendly working conditions. A.I. Chulok and others. "Information methods for optimizing the technology of cleaning and regeneration of used lubricants." To optimize the technology for cleaning and regenerating oil-emulsion wastewater, an automated information retrieval system AIPS-SM has been created, the core of which is information and mathematical software used to model, analyze and predict the dependencies: chemical structure of lubricant components (LM) - environmental properties of formulations; initial raw materials and reagents - the output of the target and by-products (environmentally hazardous) products; cleaning and regeneration schemes for SM - environmental and technical and economic indicators of the effectiveness of the disposal of spent SM.
The market economy hit our country at the end of the 20th century like an avalanche, abruptly and unexpectedly. Then, in a short period of time, foreign markets for goods and capital opened up. In response to this circumstance, new banks, insurance companies and cooperatives began to be created en masse. state machine, regulating new processes in the economy, completely changed the accounting procedure, currency control rules, customs regulation.
In contact with
In such a general situation (at that time) in the country, a shortage of personnel with education corresponding to the new reality naturally manifested itself. The demand for specialists in finance, credit, law, accounting, and so on has skyrocketed.
Previously popular engineering specialties in universities began to lose their appeal. Applicants were attracted by stormy streams to economic specialties. Higher educational institutions of our country (including technical ones), adapting to the spirit of the times, massively opened the corresponding faculties for the training of economists, lawyers, accountants.
In the time that has elapsed since then, and this is already more than 20 years, millions of specialists with higher education in the above areas have turned out to be released by universities “into adulthood”. Undoubtedly, most of them are employed to this day. But recently, taking into account the growing technological progress, there has been an increasing shortage of precisely engineering personnel, professionals in production and construction. As a result, there was a need for specialists in technosphere safety.
Who is he, a specialist in technosphere safety?
To answer this question, you need to understand the terminology.
Modern man, for the purpose of the most comfortable stay, modifies his environment with the help of technical means (machines and mechanisms) and man-made objects (roads, airports, water utilities, hydroelectric power plants, buildings, and others). The part of the biosphere that has undergone such a transformation is called the technosphere.
In this way, a technosphere safety specialist is a person having a set of professional knowledge and skills with which he can:
- ensure the safe activities of people in the environment to form a comfortable technosphere for life;
- using modern methods of control and forecasting, as well as advanced technical means, to ensure the safety of human life and health;
- ensure the safety of the environment from the consequences of human activity, minimizing its man-made impact on nature.
Technospheric safety and environmental management are related concepts, but not the same thing. Environmental management is a measure to purposefully change the properties of natural objects in order to increase their consumer value and more efficient use of land resources.
Where and by whom can a technosphere safety specialist work?
Before answering the question: where you can get a specialty in technosphere safety, you need to understand whether you need to get it or not. And for this, you must first find out where the future graduate will be able to work, and what his profession will be called.
At present, experts in technosphere safety are in high demand. By the date of graduation from a university and receiving a diploma of higher education, graduates usually do not have a choice: who and where to work, since they already know this.
Even during the internship, most future graduates receive offers of further employment. There are many options for where to start their working career.
It can be like public(Ministry of Emergency Situations, Rostrudinspektsiya, Ministry of Natural Resources and others), and private (Aeroflot, Rusal, Megapolis and others) structures, for the following types of activities (by profession):
- safety engineer;
- fire safety engineer;
- industrial safety engineer;
- environmental safety engineer;
- engineer for technical supervision;
- occupational health and safety engineer;
- manager (analyst, expert) for security and risks;
- inspector of state supervision and control;
- rescuer;
- environmental engineer;
- and others.
As can be seen from the list, the choice of options for the future profession is very wide. Diploma in technospheric safety who to work with, you still have to choose.
Activities can be divided into the following three groups:
- research;
- design and engineering;
- managerial.
Jobs and salary
The number of technically complex projects that have been implemented or are still being implemented in our country has increased dramatically in recent years compared to what was being built 20 years ago. Among them:
The list goes on. During the implementation of each such project Dozens and hundreds of specialists in technosphere safety are involved. There are always vacancies, the main condition is the readiness for business trips. If there is no such readiness, then you need to look at employment options in a technology company or research organization.
The question of wages is very relevant for all categories of working citizens. If you look at popular job search sites on the Internet, you can see (just type in the search: technosphere safety vacancies) that the level of monthly compensation for a specialist (bachelor) in technosphere safety, on average, is from 30 to 40 thousand rubles. At the same time, in Moscow it rises to 70 thousand. And in the regions, the “fork” is from 20 to 60 thousand rubles.
Where can I get education in technosphere safety and forms of education
In accordance with the All-Russian Classifier of Specialties in Education (OKSO), the specialty "Technosphere Safety" has the following code designations:
- 03/20/01 - Bachelor's degree;
- 20.04.01 - Master's degree;
- 06/20/01 - qualification for postgraduate studies.
For those who want to get an education in the above specialty Several Moscow universities have opened their doors, including:
As can be seen from the above list, training is carried out in technical universities at engineering faculties. For example, at the Moscow State Technical University named after N.E. Bauman, the Department of Ecology and Industrial Safety was opened at the Faculty of Power Engineering.
Students are trained on the basis of secondary education of 11 classes and takes four years on a full-time basis. Perhaps admission to the evening or correspondence department, which takes five years to study.
For admission, you need to pass an exam in mathematics, Russian language and physics or chemistry (at the discretion of the university).
What subjects do future specialists study at the university?
In the direction of technosphere safety, universities teach students both the main (basic) disciplines for all technical universities (engineering physics, descriptive geometry, mechanics, thermal physics, fluid dynamics, electronics and electrical engineering), and special subjects (supervision and control in the field of security, medical biological foundations of safety, technosphere safety management, etc.).
Conclusion
Specialists in technosphere safety are in high demand in the modern world due to the importance of the profession. Work does not mean sitting in a stuffy office"from call to call" and will be of interest to young people leading an active lifestyle. Technological progress makes it possible to implement more and more complex projects, and real professionals have a chance to participate in this process.
Environmental engineering takes care of the conservation of nature and resources. Service employees are trained and then engaged in ensuring the protection of protected areas, forests, rivers and air.
Description of specialty
The specialty allows you to prepare professionals who will make sure that human life does not have a negative impact on the state of nature. Environmental protection is based on the ability to meet human needs without harming the natural environment.
Environmental engineers monitor the impact of waste and emissions on the state of the environment, take measures to ensure the safety and conservation of nature and resources.
Tasks for graduates
Ecology graduates are given a number of tasks that they must fulfill for the benefit of mankind.
Environmental tasks:
- problem solving through the introduction of modern technologies;
- analysis and forecasting of the environmental situation in the future;
- promotion of nature conservation;
- ecosystem modeling;
- restoration of devastated reserves, forests, parks;
- creation of programs for the protection of the environment.
The activities of employees are carried out on the territory of the region, the state or in the international community of environmentalists.
Applying Knowledge in Practice: Modern Methods for the Protection of Nature and its Resources
Ecologists can work within one state or in an international association. The profession is important for the future of the planet. Graduates have two tasks:
- identification of pollution sources;
- destruction of sources of pollution.
Engineering protection uses biotechnology to help get rid of contaminants.
Environmental engineers install special equipment that allows you to:
- dispose of waste water;
- to clear reservoirs of inorganic garbage;
- restore soils after exposure to poisons and heavy metals;
- oxidize plant waste;
- clear the air.
Special equipment protects nature from human activities, preserves it for posterity. The duties of an ecologist include active promotion of the restoration of the natural habitat of wild animals, planting artificial forests, and environmental education of the future generation.
Environmental measures can be classified in two main areas: 1) measures taken to prevent negative impacts on the environment; 2) measures aimed at eliminating the consequences of harmful effects.
Engineering environmental measures are divided into two groups.
Measures that reduce the emission of pollutants and the level of harmful effects:
– improvement of technological processes and introduction of low-waste and waste-free technologies;
- changing the composition and improving the quality of the resources used (removing sulfur from fuel, switching from coal to oil or gas, from gasoline fuel to hydrogen, etc.);
– installation of treatment facilities with subsequent disposal of captured waste;
- integrated use of raw materials and reduction of consumption of resources, the production of which is associated with environmental pollution;
- research and development, the results of which make it possible and stimulate the implementation of the above measures - the development of standards for the quality of the natural environment, the assessment of the ecological capacity of ecosystems, the design of new technologies, the creation of a system of environmental and economic indicators of economic activity, etc.
Measures to reduce the spread of pollutants and other harmful effects:
– construction of high and ultra-high pipes, wastewater outlets of various designs to optimize the conditions for their dilution, etc.;
– neutralization of emissions, their burial and conservation;
– post-treatment of the resources used before they reach the consumer (installation of air conditioners and air ducts for indoor air purification, metro, tap water purification, etc.);
- arrangement of sanitary protection zones around industrial enterprises and water bodies, planting greenery in cities and towns;
– the optimal location of industrial enterprises and motorways (taking into account hydrometeorological factors) to minimize their negative impacts;
– rational planning of urban development, taking into account the wind rose and noise loads, etc.
Of great importance is the rational distribution of funds between the two considered areas. If 10 - 20 years ago, in many industries, preference was often given to cheaper and more effective measures of the second group from the standpoint of a particular region, but now measures of the first group are more often used.
Strategic measures are the development of resource-saving, low-waste and waste-free technologies. Wasteless technology should become an engineering ideal.
However, it is difficult to imagine, for example, recycling water supply in public utilities, especially when huge volumes of domestic wastewater are discharged. Therefore, the improvement of technologies for the treatment of harmful emissions into the atmosphere and wastewater will remain a problem of paramount importance for a long time to come.
Let us consider as examples some of the principal schemes for the treatment of air emissions and wastewater, as well as the disposal, detoxification and disposal of solid waste.
Purification of gas emissions into the atmosphere. 85% of all air pollution is solid pollution (dust of various composition and origin). To clean gas emissions from dust, dust is usually deposited in gravitational, centrifugal, electric or acoustic fields, absorption, chemisorption and reagent methods. Cleaning is most often carried out in devices - cyclones (Fig. 12).
Rice.12. Cylindrical cyclone
The gas flow is introduced through the inlet into the body and performs a rotational-translational movement along the body to the hopper. Under the action of centrifugal force, a dust layer is formed on the wall of the cyclone.
The separation of dust from gas occurs due to the rotation of the gas flow in the hopper by 180°. The gas stream cleared of dust forms a vortex and leaves the cyclone through the outlet pipe.
To filter gases from dust, various filters are used: fabric, with packing or with a bulk filter layer, electrostatic precipitators. Electrostatic precipitators are the most advanced devices for cleaning gases from dust and fog particles. The cleaning process is based on the so-called impact ionization of the gas in the discharge zone. Polluted gases entering the electrostatic precipitator are partially ionized due to external influences. With a sufficiently high voltage applied to the electrodes, in an electric field, the movement of ions and electrons is so accelerated that, colliding with gas molecules, they ionize them, splitting them into positive ions and electrons. The resulting ion flow is accelerated by an electric field, and the reaction is repeated (an avalanche-like process sets in). This process is called impact ionization. Electrostatic precipitators are usually made with negative electrodes, while positively charged particles are deposited under the influence of electrostatic, aerodynamic forces and gravity. Periodic cleaning of the filter is achieved by shaking the electrodes. Several types of designs of dry and wet electrostatic precipitators are used in industry. Depending on the shape of the electrodes, tubular and plate electrostatic precipitators are distinguished (Fig. 13).
Rice. 13. Plate electrostatic precipitator
Purification of emissions from gaseous toxic impurities is carried out using:
1) absorption (lat. absorption –- absorption, dissolution) - flushing emissions with liquid solvents;
2) chemisorption - washing with solutions of reagents that chemically bind impurities;
3) adsorption (lat. adsorbere– absorption) – absorption of impurities by solid active substances;
4) chemical transformations of impurities in the presence of catalysts (catalytic methods).
During absorption, the absorbing liquid (absorbent) is selected depending on the solubility of the removed gas in it, the temperature and its partial pressure. For example, to remove ammonia NH 3 , hydrogen chloride HCI or hydrogen fluoride HF from process emissions, it is advisable to use water as an absorbent, since the solubility of these gases in water is high - hundredths of a gram per 1 kg of water. In other cases, you can use a solution of sulfuric acid (for trapping water vapor) or viscous oils (for trapping aromatic hydrocarbons), etc.
Chemisorption is based on the absorption of gases by reagents with the formation of low-volatile or slightly soluble compounds. An example is the purification of a gas-air mixture from hydrogen sulfide using an arsenic-alkaline reagent:
H 2 S + Na 4 As 2 S 5 O 2 \u003d Na 4 As 2 S 6 O + H 2 O
The regeneration of the solution is carried out by its oxidation with oxygen contained in the purified air:
Na 4 As 2 S 6 O + O 2 \u003d 2 Na 4 As 2 S 5 O 2 + 2S
In this case, sulfur is the by-product. Other reagents may also be used ion exchangers. Ionites are solids capable of exchanging ions with liquid or gaseous mixtures filtered through them. These are either natural materials (zeolites or clays) or synthetic polymers (resins). For example, when filtering a gas mixture containing ammonia NH 3 through a wet cation-type ion exchanger (cation exchanger), ammonia NH 3 is added to the cation exchanger:
R–H + NH 3 → R–NH 4
Similar reactions also occur when sulfur dioxide SO 2 is removed from the gas mixture using anion-type ion exchangers (anion exchangers):
R–CO 3 + SO 2 → R–SO 3 + CO 2
R–OH + SO 2 → R–HSO 3
Regeneration of ion exchangers is carried out by washing them with water, weak solutions of acids (for cation exchangers), alkalis or soda Na 2 CO 3 (for anion exchangers).
Adsorption– the process of selective absorption of gas mixture components by solids. During physical adsorption, the adsorbent molecules do not enter into chemical interaction with the molecules of the gas mixture. Requirements for adsorbents: high adsorption capacity, selectivity (lat. selectio- selection, selection), chemical inertness, mechanical strength, ability to regenerate, low cost. The most common adsorbents are active carbons, silica gels, aluminosilicates. As the temperature increases, the adsorption capacity decreases. The regeneration process is based on this property, which is carried out either by heating the saturated adsorbent to a temperature above the working one, or by blowing it with hot steam or air.
catalytic methods gas purifications are based on the use of catalysts that accelerate chemical reactions. In recent years, catalytic methods have been used to neutralize vehicle exhaust gases, i.e., convert toxic nitrogen oxides NO and carbon CO into non-toxic nitrogen gas N 2 and carbon dioxide CO 2 . In this case, various catalysts are used: copper-nickel alloy, platinum on alumina, copper, nickel, chromium, etc.:
Cleaning of drains. Depending on the type of processes occurring in wastewater treatment plants, there are mechanical, physico-chemical and biological wastewater treatment. At the treatment plant, large masses of sediments are formed, which are prepared for further use: they are dehydrated, dried, neutralized and disinfected. After treatment, before being discharged into water bodies, wastewater must be disinfected in order to destroy pathogenic microorganisms.
mechanical cleaning designed to retain undissolved impurities. Mechanical cleaning facilities include: gratings and sieves (for retaining large impurities), sand traps (for trapping mineral impurities, sand), settling tanks (for slowly settling and floating impurities) and filters (for small undissolved impurities). Specific pollution of industrial wastewater is removed using grease traps, oil traps, oil and resin traps, etc. Mechanical treatment is, as a rule, a preliminary step before biological treatment. In some cases, mechanical treatment can be limited: for example, if a small amount of wastewater is discharged into a very large body of water, or if water after mechanical treatment is reused at the enterprise. With mechanical cleaning, it is possible to delay up to 60 % undissolved impurities (Fig. 14).
Fig.14. Technological scheme of a treatment plant with mechanical wastewater treatmentwaters
Physical and chemical cleaning methods are mainly used for industrial wastewater. These methods include: reagent purification (neutralization, coagulation, ozonation, chlorination, etc.), sorption, extraction (lat. extrahere – extract), evaporation (lat. evaporatio – evaporation), flotation, electrodialysis, etc.
The most widely used are methods of reagent purification using coagulants, which are used as aluminum sulfate AI 2 (SO 4) 3, ferric chloride FeCl 3, ferrous sulfate Fe 2 (SO 4) 3, lime CaCO 3, etc. Coagulant salts contribute to coarsening particles, forming flakes, which makes it possible to further precipitate and filter fine undissolved, colloidal and partially dissolved impurities. In some cases, physical and chemical treatment provides such a deep removal of contaminants that subsequent biological treatment is not required (Fig. 15).
Fig.15. Technological scheme of a treatment plant with physical and chemical wastewater treatment
Biological treatment wastewater is based on the use of microorganisms that, in the course of their life, destroy organic compounds, i.e. mineralize them. Microorganisms use organic matter as a source of nutrients and energy. Biological treatment facilities are conditionally divided into two types: facilities in which processes take place under conditions close to natural, and those in which treatment takes place under artificially created conditions. The former include filtration fields and biological ponds, while the latter include biofilters and aeration tanks.
Filter fields- these are land plots artificially divided into sections, over which wastewater is evenly distributed, filtering through the pores of the soil. The filtered water is collected in drainage pipes and ditches and flows into reservoirs. A biological film of aerobic microorganisms capable of mineralizing organic matter is formed on the soil surface.
biological ponds- These are specially created shallow reservoirs where natural biochemical processes of water self-purification take place under aerobic (oxygen) and anaerobic (oxygen-free) conditions. Saturation of water with oxygen occurs due to natural atmospheric aeration and photosynthesis, but artificial aeration can also be used.
Biofilters- structures in which conditions are created for the intensification of natural biochemical processes. These are tanks with filter material, drainage and a device for distributing water. Waste water with the help of distributing devices is periodically spilled over the loading surface, filtered and discharged into a secondary sump. On the surface of the filter, a biofilm of various microorganisms gradually matures, which perform the same function as on the filtration fields, i.e., mineralize organic substances. The dead biofilm is washed off with water and retained in the secondary clarifier.
Aerotank – this is a reservoir into which waste water (after mechanical treatment), activated sludge and air enter. Activated sludge flakes are a biocenosis of aerobic mineralizing microorganisms (bacteria, protozoa, worms, etc.). For the normal functioning of microorganisms, constant aeration (blowing with air) of water is necessary. From the aerotank, wastewater mixed with activated sludge enters the secondary settling tanks, where the sludge is deposited. The bulk of it is returned to the aerotank, and water is supplied to contact tanks for chlorination - disinfection (Fig. 16).
Fig.16. Technological scheme of the plant with biological wastewater treatment
Disinfection is the final stage of wastewater treatment before being discharged into a reservoir. The most widespread method of water disinfection by chlorination with gaseous chlorine C1 2 or bleach CaCl(OCI). Electrolysis plants are also used to produce sodium hypochlorite NaClO from common salt NaCl. Disinfection with other bactericidal substances is also possible.
sludge treatment, formed in the process of wastewater treatment, is carried out in order to reduce their moisture content and volume, disinfection and preparation for disposal. Coarse waste (rags, paper, food residues, etc.) is retained on the grates, which are taken to landfills or sent to special facilities after crushing. Sand from the sand traps enters the sand platforms for dehydration, and then is taken out and used for its intended purpose. An independent group of facilities is used to treat sediments from settling tanks: sludge beds, digesters, aerobic stabilizers, dehydration and drying plants. The most widely used digesters.
Methane tanks- these are hermetically sealed tanks, where anaerobic bacteria in thermophilic conditions (t = 30 - 43 ° C) ferment raw sludge from primary and secondary clarifiers. In the process of fermentation, gases are released: methane CH 4, hydrogen H 2, carbon dioxide CO 2, ammonia NH 3, etc., which can then be used for various purposes.
Wastewater sludge discharged from digesters has a moisture content of 97% and is inconvenient for disposal. To reduce their volume, dehydration is used in sludge beds or vacuum filters, centrifuges and other facilities. As a result, the dehydrated sludge decreases in volume by 7–15 times and has a moisture content of 50–80%.
Burning precipitation applies if they are not subject to other types of processing and disposal. World experience shows that 25% of the sludge generated at wastewater treatment plants is used in agriculture, 50% is disposed of in landfills and about 25% is incinerated. In connection with the tightening of sanitary requirements for the quality of precipitation, the possibility of using them in agriculture is reduced. Specialists are increasingly turning to the incineration of precipitation.
The choice of the optimal technological scheme for the treatment of sewage sludge depends on their properties, chemical composition, quantity, climatic conditions, availability of territories for sludge sites and other factors.
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65. Environmental Engineering
Main directions environmental protection engineering from pollution and other types of anthropogenic impacts are the introduction of resource technology, biotechnologies, recycling and detoxification of waste, and most importantly, the greening of all production, which would ensure the inclusion of all types of interaction with the environment in the natural cycles of the circulation of substances. These fundamental directions are based on the cyclic nature of material resources and are borrowed from nature, where, as is known, closed cyclic processes operate. Technological processes, in which all interactions with the environment are fully taken into account and measures are taken to prevent negative consequences, are called eco-friendly. Like any ecological system, where matter and energy are spent sparingly and wastes of some organisms serve as an important condition for the existence of others, an ecologized production process controlled by man must follow biospheric laws, and first of all, the law of the circulation of substances.
Another way, for example, the creation of all kinds, even the most advanced treatment facilities, does not solve the problem, since this is a struggle with the effect, and not with the cause. The main cause of biosphere pollution is resource-intensive and polluting technologies for processing and using raw materials. It is these so-called traditional technologies that lead to a huge accumulation of waste and the need for wastewater treatment and solid waste disposal.
The latest type of engineering protection is the introduction of biotechnological processes based on the creation of products, phenomena and effects necessary for humans with the help of microorganisms. Biotechnology has found wide application in the protection of the natural environment, in particular, in solving the following applied issues:
1) disposal of the solid phase of wastewater and municipal solid waste using anaerobic digestion;
2) biological treatment of natural and waste water from organic and inorganic compounds;
3) microbial recovery of contaminated soils, obtaining microorganisms capable of neutralizing heavy metals in sewage sludge;
4) composting;
5) creation of a biologically active sorbent material for purification of polluted air.
Engineering protection of atmospheric air provides for the use at enterprises of dry dust collectors - cyclones, dust settling chambers or wet dust collectors - scrubbers, as well as filters - fabric, granular or high-performance electrostatic precipitators.
66. Production waste, its disposal, detoxification and recycling
Industrial waste- these are the remains of raw materials, materials, semi-finished products formed during the production of products or the performance of any work and have lost their original consumer properties in whole or in part.
Environmental crises that periodically arise in different places in Russia are in many cases due to the negative impact of the so-called hazardous waste. In Russia, about 10% of the total mass of solid waste is classified as hazardous. Among them are metal and galvanic sludge, glass fiber waste, asbestos waste and dust, residues from the processing of acid resins, tar and tar, used radio engineering products, etc. Hazardous waste is understood as waste containing in its composition substances that have one of the dangerous properties - toxicity, explosiveness, infectiousness, fire hazard, etc. The greatest threat to humans and the entire biota is posed by hazardous wastes containing chemicals of I and II toxicity classes. First of all, these are wastes containing radioactive isotopes, dioxins, pesticides, benzapyrene and some other substances.
According to environmental specialists, only in Russia the total activity of unburied radioactive waste is 1.5 billion curies, which is equal to thirty Chernobyls.
Liquid radioactive waste(RAW) in the form of a concentrate is stored in special containers, solid - in special storage facilities. In our country, according to the data for 1995, the level of filling of containers and warehouses for radioactive waste at nuclear power plants was more than 60%, and by 2004 - 95%. The accumulation of radioactive waste in the Russian fleets is steadily increasing, especially after the prohibition in 1993 of the discharge of radioactive waste into the sea. At a number of enterprises of the Ministry of Atomic Energy (PA "Mayak", Siberian Chemical Plant) and other liquid low- and medium-level radioactive waste are stored in open water bodies, which can lead to radioactive contamination of large areas in the event of sudden natural disasters - floods, earthquakes, as well as the penetration of radioactive substances into The groundwater.
Dioxins- synthetic organic substances from the class of chlorohydrocarbons.
Waste from metallurgical production are used either in road construction or for the manufacture of building cinder blocks. Recycling- this is a repeated (sometimes many times) sequential processing of previously generated waste. Waste Detox- release them from harmful components on specialized installations.
