Theoretical foundations of technological processes of environmental protection

1. General characteristics of protection methods environment from industrial pollution

Environmental protection is an integral part of the concept of sustainable development of human society, which means long-term continuous development that meets the needs of people living today without compromising the satisfaction of the needs of future generations. The concept of sustainable development cannot be realized if specific action programs are not developed to prevent environmental pollution, which also include organizational, technical and technological developments for the development of resource-, energy-saving and low-waste technologies, reduction of gas emissions and liquid discharges, processing and disposal household waste, reduction of energy impact on the environment, improvement and use of environmental protection means.

Organizational and technical methods of environmental protection can be divided into active and passive methods. Active methods of environmental protection are technological solutions for the creation of resource-saving and low-waste technologies.

Passive methods of environmental protection are divided into two subgroups:

rational placement of pollution sources;

localization of pollution sources.

Rational location implies a territorial rational location of economic facilities, which reduces the burden on the environment, and localization is essentially a phlegmatization of pollution sources and a means of reducing their emissions. Localization is achieved by using various environmental technologies, technical systems and devices.

Many environmental technologies are based on physical and chemical transformations. In physical processes, only the shape, size, state of aggregation and other physical properties of substances change. Their structure and chemical composition are saved. Physical processes dominate in the processes of dust collection, the processes of physical absorption and adsorption of gases, wastewater treatment from mechanical impurities, and in other similar cases. Chemical processes change the chemical composition of the treated stream. With their help, toxic components of gas emissions, liquid and solid waste, wastewater are converted into non-toxic.

Chemical phenomena in technological processes are often developed under the influence of external conditions(pressure, volume, temperature, etc.) in which the process is implemented. In this case, there are transformations of some substances into others, a change in their surface, interfacial properties, and a number of other phenomena of a mixed (physical and chemical) nature.

The totality of interrelated chemical and physical processes occurring in a material substance is called physicochemical, borderline between physical and chemical processes. Physical and chemical processes are widely used in environmental technologies (dust and gas collection, wastewater treatment, etc.).

A specific group is made up of biochemical processes - chemical transformations occurring with the participation of living entities. Biochemical processes form the basis of life

all living organisms of flora and fauna. A significant part of the agricultural production and food industry, such as biotechnology, is built on their use. The product of biotechnological transformations occurring with the participation of microorganisms are substances of inanimate nature. In the theoretical foundations of environmental protection technology, based on the general laws of physical and colloidal chemistry, thermodynamics, hydro- and aerodynamics, the physico-chemical essence of the main processes of environmental technologies is studied. Such systems approach to environmental processes allows us to make generalizations on the theory of such processes, to apply a unified methodological approach to them.

Depending on the main patterns that characterize the course of environmental processes, the latter are divided into the following groups:

mechanical;

hydromechanical;

mass transfer,

chemical;

physical and chemical;

thermal processes;

biochemical;

processes complicated by a chemical reaction.

The processes of protection against energy impacts, mainly based on the principles of reflection and absorption of excess energy of the main technological processes nature management.

To mechanical processes, the basis of which is mechanical impact on solid and amorphous materials, include grinding (crushing), sorting (classification), pressing and mixing bulk materials. The driving force of these processes are mechanical pressure forces or centrifugal force.

To hydromechanical processes, the basis of which is hydrostatic or hydromechanical action on media and materials,

include mixing, sedimentation (precipitation), filtration, centrifugation. The driving force behind these processes is hydrostatic pressure or centrifugal force.

Mass transfer (diffusion) processes, in which, along with heat transfer, the transition of a substance from one phase to another due to diffusion plays an important role, include absorption, adsorption, desorption, extraction, rectification, drying and crystallization. The driving force of these processes is the difference in the concentrations of the transferring substance in the interacting phases.

Chemical processes occurring with change physical properties and the chemical composition of the starting substances, are characterized by the transformation of some substances into others, a change in their surface and interfacial properties. These processes include the processes of neutralization, oxidation and reduction. The driving force behind chemical processes is the difference in chemical (thermodynamic) potentials.

Physico-chemical processes are characterized by an interconnected set of chemical and physical processes. Physical and chemical separation processes based on physical and chemical transformations of substances include coagulation and flocculation, flotation, ion exchange, reverse osmosis and ultrafiltration, deodorization and degassing, electrochemical methods, in particular, electrical gas cleaning. The driving force of these processes is the difference between the physical and thermodynamic potentials of the separated components at the phase boundaries.

Thermal processes, the basis of which is a change in the thermal state of interacting media, include heating, cooling, evaporation and condensation. The driving force of these processes is the temperature difference (thermal potentials) of the interacting media.

Biochemical processes, which are based on catalytic enzymatic reactions of the biochemical transformation of substances during the life of microorganisms, are characterized by the occurrence of biochemical reactions and the synthesis of substances at the level of a living cell. The driving force of these processes is the energy level (potential) of living organisms.

This classification is not rigid and unchanged. In reality, many processes are complicated by the flow of adjacent-parallel processes. For example, mass transfer and chemical processes are often accompanied by thermal processes. Thus, rectification, drying and crystallization can be attributed to combined heat and mass transfer processes. The processes of absorption and adsorption are often accompanied by chemical transformations. The chemical processes of neutralization and oxidation can be simultaneously considered as mass transfer processes. Biochemical processes are accompanied simultaneously by heat and mass transfer, and physicochemical processes are accompanied by mass transfer processes.

Catalytic gas cleaning methods

Catalytic gas purification methods are based on reactions in the presence of solid catalysts, i.e., on the laws of heterogeneous catalysis. As a result of catalytic reactions, impurities in the gas are converted into other compounds ...

Methods for cleaning off gases and emissions from the production of fodder yeast

Dust Collecting Methods Cleaning methods according to their basic principle can be divided into mechanical cleaning, electrostatic cleaning, and cleaning by sonic and ultrasonic coagulation...

Rationing, certification and standardization in the field of environmental protection

Rationing in the field of environmental protection is carried out in order to state regulation the impact of economic and other activities on the environment ...

Main functions of environmental monitoring natural environment

Causes of pollution of the biosphere

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Problems of environmental law of the Kyrgyz Republic

The system of environmental legislation consists of two subsystems: environmental and natural resource legislation. The subsystem of environmental legislation includes the Law on Environmental Protection ...

Pollution is a change in the natural environment (atmosphere, water, soil) as a result of the presence of impurities in it. At the same time, pollution is distinguished: anthropogenic - caused by human activities and natural - caused by natural processes ...

Chloroplasts are the centers of photosynthesis in plant cells.

The main sources of air pollution are coal-fired power plants, coal, metallurgical and chemical industries, cement, lime, oil refineries and other plants ...

China's environmental policy

Environmental protection in China is one of the basic directions of development national policy. The Chinese government pays great attention to legislative work in this area. In order to stimulate the coordination of economic...

China's environmental policy

Legal system China, designed to protect the environment, was created relatively recently. The creation of environmental laws is often the responsibility of local authorities...

Ecology: basic concepts and problems

The basis for the sustainable development of the Russian Federation is the formation and consistent implementation of a unified public policy in the field of ecology...

Energy pollution

The atmosphere always contains a certain amount of impurities coming from natural and anthropogenic sources. Among the impurities emitted by natural sources include: dust (vegetable, volcanic ...

STATE EDUCATIONAL INSTITUTION OF HIGHER PROFESSIONAL EDUCATION

MOSCOW STATE TECHNOLOGICAL UNIVERSITY "STANKIN"

FACULTY OF TECHNOLOGY

DEPARTMENT OF ENVIRONMENTAL ENGINEERING AND LIFE SAFETY

Doctor of Physics and Mathematics. sciences, professor

M.YU.KHUDOSHINA

THEORETICAL FOUNDATIONS OF ENVIRONMENTAL PROTECTION

LECTURE NOTES

MOSCOW

Introduction.

Environmental protection methods. Greening industrial production

Methods and means of environmental protection.

The environmental protection strategy is based on objective knowledge about the laws of functioning, relationships and development dynamics of the constituent elements of the environment. They can be obtained through scientific research within the framework of various fields of knowledge - natural sciences, mathematical, economic, social, public. On the basis of the regularities obtained, methods for protecting the environment are developed. They can be divided into several groups:

Propaganda methods

These methods are devoted to promoting the protection of nature and its individual elements. The purpose of their application is to form an ecological outlook. Forms: oral, printed, visual, radio and television. To achieve the effectiveness of the application of these methods, scientific developments in the field of sociology, psychology, pedagogy, etc. are used.

Legislative Methods

The fundamental laws are the constitution, which fixes the main tasks and obligations of a citizen in relation to the environment, as well as the Law on ... Legal protection land is provided by land legislation (Fundamentals ... Legal protection of subsoil (subsoil legislation, Subsoil Code) establishes state ownership of subsoil, ...

Organizational Methods

These methods include state and local organizational measures aimed at expedient, from the point of view of environmental protection, placement on the territory of enterprises, production and settlements, as well as on the solution of single and complex environmental issues and questions. Organizational methods ensure the conduct of mass, state or international economic and other activities aimed at creating effective environmental conditions. For example, the transfer of logging from the European part to Siberia, the replacement of wood with reinforced concrete and the saving of natural resources.

These methods are based on system analysis, control theory, simulation modeling, etc.

Technical Methods

They determine the degree and types of impact on the object of protection or its surrounding conditions in order to stabilize the state of the object, including:

• Termination of impact on protected objects (order, conservation, prohibition of use).

Reduce and reduce exposure (regulation), volume of use, harmful effects by cleansing harmful emissions, environmental regulation, etc.

· Reproduction of biological resources.

· Restoration of depleted or destroyed objects of protection (natural monuments, populations of plants and animals, biocenoses, landscapes).

· Strengthening the use (use in the protection of rapidly breeding commercial populations), rarefaction of populations to reduce mortality from infectious diseases.

· Changing forms of use in the protection of forests and soils.

Domestication (Przewalski's horse, eider, bison).

· Fencing with fences and nets.

· Various methods of soil protection from erosion.

The development of methods is based on fundamental and scientific and applied developments in the field of natural sciences, including chemistry, physics, biology, etc.

Technical and economic methods

• Development and improvement of treatment facilities.
• Implementation of non-waste and low-waste industries and technologies.
• Economic methods: obligatory payments for environmental pollution; payments for natural resources; fines for violation of environmental legislation; budget financing of state environmental programs; systems of state environmental funds; environmental insurance; a set of measures for economic stimulation of environmental protection .

Such methods are developed on the basis of applied disciplines, taking into account technical, technological and economic aspects.

Section 1. Physical bases of purification of industrial gases.

Topic 1. Directions for the protection of the air basin. Difficulties in cleaning gases. Features of air pollution

Air basin protection directions.

Sanitary - technical measures.

Installation of gas and dust cleaning equipment,

Installation of ultra-high pipes.

The criterion for the quality of the environment is the maximum permissible concentration (MAC).

2. Technological direction .

Creation of new methods for the preparation of raw materials, purifying it from impurities before being involved in production,

Creation of new technologies based in part or in full
closed cycles

Replacement of raw materials, replacement of dry methods of processing dusty materials with wet ones,

Automation of production processes.

planning methods.

Installation of sanitary protection zones, which are regulated by GOST and building codes,

The optimal location of enterprises, taking into account the wind rose,
- removal of toxic production facilities outside the city limits,

Rational urban planning,

Landscaping.

Control and prohibitive measures.

Maximum allowable concentration,

Maximum allowable emissions,

Emission control automation,

Prohibition of certain toxic products.

Difficulties in cleaning gases

The problem of purification of industrial gases is primarily due to the following reasons:

· Gases are diverse in their composition.

The gases have high temperature and a lot of dust.

· The concentration of ventilation and process emissions is variable and low.

The use of gas cleaning plants requires their continuous improvement

Features of air pollution

First of all, they include the concentration and disperse composition of dust. Usually 33-77% of the volume of pollution are particles up to 1.5 in size ... Atmospheric inversions Normal temperature stratification is determined by the conditions when an increase in height corresponds to a decrease ...

Topic 2. Requirements for treatment facilities. Structure of industrial gases

Requirements for wastewater treatment plants. The cleaning process is characterized by several parameters. 1. Overall cleaning efficiency (n):

The structure of industrial gases.

Industrial gases and air containing solid or liquid particles are two-phase systems consisting of a continuous (continuous) medium - gases and a dispersed phase (solid particles and liquid droplets), such systems are called aerodisperse or aerosols. Aerosols are divided into three classes: dust , smoke, fog.

Dust.

Consists of solid particles dispersed in a gaseous medium. Formed as a result mechanical grinding solids to powders. These include: aspiration air from crushing, grinding, drilling units, transport devices, sandblasters, machines for machining products, powder packaging departments. These are polydisperse and unstable systems with particle sizes of 5-50 µm.

Smokes.

These are aerodisperse systems consisting of particles with low vapor pressure and low sedimentation rate. They are formed during sublimation and condensation of vapors as a result of chemical and photochemical reactions. The particle size in them is from 0.1 to 5 microns and less.

fogs.

Consist of liquid droplets dispersed in a gaseous medium, which may contain solutes or suspended solids. They are formed as a result of condensation of vapors and when a liquid is sprayed into a gaseous medium.

Topic 3. Main directions of gas flow hydrodynamics. Continuity equation and Navier-Stokes equation

Fundamentals of gas flow hydrodynamics.

Consider the action of the main forces on the elementary volume of gas (Fig. 1).

Rice. 1. The action of forces on an elementary volume of gas.

The theory of gas flow movement is based on two basic equations of hydrodynamics: the continuity (continuity) equation and the Navier-Stokes equation.

Continuity equation

∂ρ/∂τ + ∂(ρ x V x)/∂x + ∂(ρ y V y)/∂y + ∂(ρ z V z)/∂z = 0 (1)

where ρ is the density of the medium (gases) [kg/m3]; V - speed of gas (medium) [m/s]; V x , V y , V z are the component velocity vectors along the X, Y, Z coordinate axes.

This equation is the Law of Conservation of Energy, according to which a change in the mass of a certain elementary volume of gas is compensated by a change in density (∂ρ/∂τ).

If ∂ρ/∂τ = 0 - steady motion.

Navier-Stokes equation.

– ∂px/∂x + μ(∂2Vx/∂x2 + ∂2Vx/∂y2 + ∂2Vx/∂z2) = ρ (∂Vx/∂τ +… – ∂py/ ∂y + μ(∂2Vy/∂ x2 + ∂2Vy/∂y2 + ∂2Vy/∂z2) =…

Border conditions

. Fig.2 Gas flow around the cylinder.

Initial conditions

Initial conditions are set to characterize the state of the system at the initial time.

Boundary conditions

The boundary and initial conditions constitute the boundary conditions. They highlight the space-time region and ensure the unity of the solution.

Topic 4. Criterial equation. Turbulent flow of liquid (gas). boundary layer

Equations (1) and (2) form a system with two unknowns - V r (gas velocity) and P (pressure). It is very difficult to solve this system, so simplifications are introduced. One such simplification is the use of similarity theory. This makes it possible to replace system (2) with one criterion equation.

criterion equation.

f(Fr, Eu, Re r) = 0

These criteria Fr, Eu, Re r are based on experiments. The type of functional connection is established empirically.

Froude criterion

It characterizes the ratio of the force of inertia to the force of gravity:

Fr \u003d Vg 2 / (gℓ)

where Vg 2 - the force of inertia; gℓ- force of gravity; ℓ - defining linear parameter, determines the scale of gas movement [m].

The Froude criterion plays an important role when the moving flow system is significantly affected by gravitational forces. When solving many practical problems, the Froude criterion degenerates, since gravity is taken into account.

Euler criterion(secondary):

Eu = Δp/(ρ g V g 2)

where Δp - pressure drop [Pa]

The Euler criterion characterizes the ratio of the pressure force to the force of inertia. It is not decisive and is regarded as secondary. Its form is found by solving equation (3).

Reynolds criterion

It is the main one and characterizes the ratio of inertial forces to the friction force, turbulent and rectilinear motion.

Re r = V g ρ g ℓ / μ g

where μ is the dynamic viscosity of the gas [Pa s]

The Reynolds criterion is the most important characteristic of the gas flow movement:

• at low values ​​of the Reynolds criterion Re, friction forces predominate, and a stable rectilinear (laminar) gas flow is observed. The gas moves along the walls that determine the flow direction.
• as the Reynolds criterion increases, the laminar flow loses stability and, at a certain critical value of the criterion, passes into turbulent regime. In it, turbulent masses of gas move in any direction, including the direction of the wall and the body in a flow.

Turbulent fluid flow.

Automodel mode.

Turbulent pulsations - determined by the speed and scale of movement. Movement scales: 1. The fastest pulsations have the largest scale 2. When moving in a pipe, the scale of the largest pulsations coincides with the pipe diameter. The magnitude of the ripple is determined ...

Pulsation speed

Vλ = (εnλ / ρg)1/3 2. A decrease in the speed and scale of the pulsation corresponds to a decrease in the number ... Reλ = Vλλ / νg = Reg(λ/ℓ)1/3

Automodel mode

ξ = A Reg-n where A, n are constants. With an increase in inertial forces, the exponent n decreases. The more intense the turbulence, the smaller n.…

boundary layer.

1. According to the Prandtl-Taylor hypothesis, the motion in the boundary layer is laminar. Due to the absence of turbulent motion, the transfer of matter ... 2. In the boundary layer, turbulent pulsations gradually decay, approaching ... In the diffuse sublayer z<δ0, у стенки молекулярная диффузия полностью преобла­дает над турбулентной.

Topic 5. Properties of particles.

Basic properties of suspended particles.

I. Density of particles.

The density of particles can be true, bulk, apparent. Bulk density takes into account the air gap between dust particles. When caking, it increases by 1.2-1.5 times. Apparent density is the ratio of the mass of a particle to the volume it occupies, including pores, voids, and irregularities. A decrease in the apparent density in relation to the true one is observed in dust prone to coagulation or sintering of primary particles (soot, non-ferrous metal oxides). For smooth monolithic or primary particles, the apparent density coincides with the true one.

II. Dispersion of particles.

Particle size is determined in several ways: 1. Clear size - the smallest size of the sieve openings through which more ... 2. The diameter of spherical particles or the largest linear size of particles of irregular shape. It is applied in…

Distribution types

Different workshops have different composition of emitted gases, different composition of contaminants. The gas must be examined for the content of dust, consisting of particles of various sizes. To characterize the disperse composition, the percentage distribution of particles per unit volume by the number f(r) and by mass g(r) is used - counting and mass distributions, respectively. Graphically, they are characterized by two groups of curves - differential and integral curves.

1. Differential distribution curves

A) countable distribution

The fractions of particles whose radii are in the interval (r, r+dr) and obey the function f(r) can be represented as:

f(r)dr=1

The distribution curve that can describe this function f(r) is called the differential distribution curve of particles according to their size according to the number of particles (Fig. 4).

Rice. 4. Differential curve of aerosol particle size distribution according to their number.

B) Mass distribution.

Similarly, we can represent the particle mass distribution function g(r):g(r)dr=1

It is more convenient and popular in practice. The form of the distribution curve is shown in the graph (Fig. 5).

0 2 50 80 µm

Rice. Fig. 5. Differential curve of distribution of aerosol particles by size by their mass.

Integral distribution curves.

D(%) 0 10 100 µm Fig. 6. Integral curve of passages

Influence of dispersion on the properties of particles

The dispersion of particles affects the formation of the free energy of the surface and the degree of stability of aerosols.

Free energy of the surface.

Wednesday

Surface tension.

Aerosol particles, due to their large surface, differ from the starting material in some properties that are important for the practice of dedusting.

The surface tension for liquids at the interface with air is now precisely known for various liquids. It is, for example, for:

Water -72.5 N cm. 10 -5 .

For solids, it is significant and numerically equal to the maximum work expended on the formation of dust.

There are very few gases.

If the molecules of a liquid interact with the molecules of a solid more strongly than with each other, the liquid spreads over the surface of the solid, wetting it. Otherwise, the liquid collects into a drop, which would have a round shape if gravity did not act.

Scheme of the wettability of rectangular particles.

The diagram (Fig. 11) shows:

a) immersion of a wetted particle in water:

b) immersion in water of a non-wettable particle:

Fig.11. Wetting scheme

The wetting perimeter of particles is the boundary of the interaction of three media: water (1), air (2), solid body (3).

These three environments have delimiting surfaces:

Liquid-air surface with surface tension δ 1.2

Air-solid surface with surface tension δ 2.3

Surface "liquid - solid" with surface tension δ 1.3

Forces δ 1.3 and δ 2.3 act in the plane of a solid body per unit length of the wetting perimeter. They are directed tangentially to the interface and perpendicular to the wetting perimeter. The force δ 1.2 is directed at an angle Ө, called the contact angle (wetting angle). If we neglect the force of gravity and the lifting force of water, then when an equilibrium angle Ө is formed, all three forces are balanced.

The equilibrium condition is determined Young's formula :

δ 2.3 = δ 1.3 + δ 1.2 cos Ө

Angle Ө varies from 0 to 180°, and Cos Ө varies from 1 to –1.

At Ө >90 0, the particles are poorly wetted. Complete non-wetting (Ө = 180°) is not observed.

Wetted (Ө >0°) particles are quartz, talc (Ө =70°) glass, calcite (Ө =0°). Non-wettable particles (Ө = 105°) are paraffin.

Wetted (hydrophilic) particles are drawn into the water by the force of surface tension acting at the water-air interface. If the density of a particle is less than the density of water, gravity is added to this force and the particles sink. If the density of the particle is less than the density of water, then the vertical component of the surface tension forces decreases by the buoyant force of the water.

Non-wettable (hydrophobic) particles are supported on the surface by surface tension forces, the vertical component of which is added to the lift force. If the sum of these forces exceeds the force of gravity, then the particle remains on the surface of the water.

Water wettability affects the performance of wet dust collectors, especially when working with recirculation - smooth particles are wetted better than particles with an uneven surface, since they are more covered with an absorbed gas shell, which makes wetting difficult.

According to the nature of wetting, three groups of solids are distinguished:

1. hydrophilic materials that are well wetted by water are calcium,
most silicates, quartz, oxidizable minerals, alkali halides
metals.

2. hydrophobic materials poorly wetted by water - graphite, sulfur coal.

3. absolutely hydrophobic bodies are paraffin, teflon, bitumen. (Ө~180 o)

IV. Adhesion properties of particles.

Fad = 2δd where δ is the surface tension at the boundary of the solid and air. The adhesion force is directly proportional to the first power of the diameter, and the force that breaks the aggregate, for example, gravity or ...

V. Abrasiveness

Abrasiveness is the intensity of metal wear, at the same gas velocities and dust concentrations.

The abrasive properties of the particles depend on:

1. hardness of dust particles

2. shape of dust particles

3. dust particle size

4. Density of dust particles

The abrasive properties of the particles are taken into account when choosing:

1. velocity of dusty gases

2. wall thicknesses of apparatuses and flue gases

3. facing materials

VI. Hygroscopicity and solubility of particles.

Depends on:

1. chemical composition of dust

2. Dust particle chamber

3. shape of dust particles

4. The degree of surface roughness of dust particles

These properties are used to trap dust in wet type apparatuses.

VII. Electrical properties of dust.

Electrical contamination of particles.

Behavior in waste gases Collection efficiency in gas cleaning devices (electric filter) … Explosion hazard

IX. The ability of dust to self-ignite and form explosive mixtures with air.

There are three groups of substances, according to the causes of ignition: 1. Substances that ignite spontaneously when exposed to air. The cause of the fire is oxidation under the influence of atmospheric oxygen (heat is released at low ...

self-ignition mechanism.

Due to the highly developed contact surface of particles with oxygen, combustible dust is capable of spontaneous combustion and the formation of explosive mixtures with air. The intensity of a dust explosion depends on:

Thermal and chemical properties of dust

Size and shape of dust particles

Dust particle concentrations

Composition of gases

Dimensions and temperatures of ignition sources

Relative content of inert dust.

When the temperature rises, ignition may occur spontaneously. Productivity, burning intensity can be different.

Intensity and duration of burning.

Dense masses of dust burn more slowly, since the access of oxygen to them is difficult. Loose and small masses of dust ignite in the entire volume. When the oxygen concentration in the air is less than 16%, the dust cloud does not explode. The more oxygen, the more likely the explosion and the greater its strength (at the enterprise when welding, when cutting metal). Minimum explosive concentrations of airborne dust - 20-500g / m 3, maximum - 700-800 g / m 3

Topic 6. Main mechanisms of particle deposition

The operation of any dust collecting apparatus is based on the use of one or more mechanisms for the deposition of particles suspended in gases. 1. Gravitational settling (sedimentation) occurs as a result of ... 2. Settling under the action of centrifugal force. It is observed during the curvilinear motion of an aerodispersed flow (flow ...

Gravitational settling (sedimentation)

F= Sch, where is the drag coefficient of the particle; S h is the cross-sectional area of ​​the particle, perpendicular to the motion; Vh - ...

Centrifugal particle settling

F=mch, V= t m – particle mass; V is the speed; r is the radius of rotation; t- relaxation time Settling time of suspended particles in centrifugal dust collectors is directly proportional to the square of the particle diameter.…

Influence of the Reynolds criterion on inertial settling.

2. With an increase in the Reynolds criterion, upon transition to turbulent motion, a boundary layer is formed on the surface of the streamlined body. As… 3. For values ​​of the criterion greater than the critical value (500), the streamlines are stronger… 4. With developed turbulence approaching the self-similar regime, the Reynolds criterion can be ignored. AT…

Engagement.

Thus, the deposition efficiency of this mechanism is higher than 0, and when there is no inertial deposition, the engagement effect is characterized by ... R = dh / d

Diffusion deposition.

where D is the diffusion coefficient, characterizes the effectiveness of the Brownian ... The ratio of internal friction forces to diffusion forces is characterized by the Schmidt criterion:

Deposition under the action of elementary charges

Elementary charging of particles can be carried out in three ways: 1. During the generation of aerosols 2. Due to the diffusion of free ions

Thermophoresis

This is the repulsion of particles by heated bodies. It is caused by forces acting from the side of the gaseous phase on the non-uniformly heated ones in it ... If the particle size is more than 1 micron, the ratio of the final speed of the process to ... Note: a negative side effect occurs when solid particles settling from hot gases onto cold ...

Diffusiophoresis.

This movement of particles is caused by the concentration gradient of the components of the gas mixture. Manifested in the processes of evaporation and condensation. When evaporating with...

Settling of particles in a turbulent flow.

Turbulent fluctuation velocities increase, vortex diameters decrease, and small-scale fluctuations perpendicular to the wall already appear on…

Use of an electromagnetic field for the sedimentation of suspended particles.

When gases move in a magnetic field, a particle is acted upon by a force directed at a right angle and in the direction of the field. As a result of such exposure… The total efficiency of particle capture under the influence of various deposition mechanisms.

Topic 7. Coagulation of suspended particles

The approach of particles can occur due to brownian motion(thermal coagulation), hydrodynamic, electrical, gravitational and others ... The rate of decrease in the countable concentration of particles

Section 3. Mechanisms for the spread of pollution in the environment

Topic 8. Mass transfer

The spread of pollution in the environment (Fig. 13) occurs mainly due to natural processes and depends on the physico-chemical properties of substances, physical processes associated with their transfer, biological processes involved in global processes circulation of substances, cyclic processes in individual ecosystems. The tendency of substances to spread is the cause of the uncontrolled regional accumulation of substances.

A - atmosphere

G - hydrosphere

L - lithosphere

F - animals

H - man

P - plants

Rice. 13. Scheme of mass transfer in the biosphere.

In the ecosphere, in the process of transfer, the physicochemical properties of molecules, vapor pressure, and solubility in water primarily play a role.

Mass transfer mechanisms

Diffusion is characterized by the diffusion coefficient [m2/s] and depends on the molecular properties of the solute (relative diffusion) and… Convection is the forced movement of solutes by the flow of water.… Dispersion is the redistribution of solutes caused by the inhomogeneity of the flow velocity field.

Soil - water

The spread of pollution in the soil occurs mainly due to natural processes. They depend on the physical and chemical properties of substances, physical ... Soil-water interface plays an important role in the transfer process. Basic…

Langmuir equation

x/m is the ratio of the mass of the adsorbed substance to the mass of the adsorbent; and - constants characterizing the considered system; is the equilibrium concentration of a substance in a solution.

Freundlich isothermal adsorption equation

K is the adsorption coefficient; 1/n - characteristic of the degree of adsorption The second equation is used mainly to describe the distribution ...

Topic 9. Receipt and accumulation of substances in living organisms. Other types of transfer

Any substance is absorbed and assimilated by living organisms. The steady state concentration is the saturation concentration. If it is higher than in ... The processes of accumulation of substances in the body: 1. Bioconcentration - enrichment with chemical compounds of the body as a result of direct replenishment from the environment ...

Topic 10. Models of impurity propagation in media

Models of impurity distribution in the aquatic environment

Distribution of pollutants in the atmosphere.

Calculation of dispersion in the atmosphere of harmful substances contained in emissions ... Criteria for assessing atmospheric pollution.

Methods for cleaning industrial emissions from gaseous pollution.

There are the following main methods:

1. Absorption- flushing of emissions with solvents of impurities.

2. Chemisorption- flushing of emissions with solutions of reagents that bind at
mixes chemically.

3. Adsorption- absorption of gaseous impurities by solid active substances.

Thermal neutralization of exhaust gases.

biochemical methods.

In gas purification technology, adsorption processes are called scrubber processes. The method consists in the destruction of gas-air mixtures into its constituent parts by... Organizing the contact of a gas stream with a liquid solvent is carried out: ... · Passing gas through a packed column.

physical adsorption.

Its mechanism is as follows:

Gas molecules stick to the surface of solids under the action of intermolecular forces mutual attraction. The heat released in this case depends on the force of attraction and coincides with the heat of steam condensation (reaches up to 20 kJ / m 3). In this case, the gas is called an adsorbate, and the surface is an adsorbent.

Advantages This method consists in reversibility: with increasing temperature, the absorbed gas is easily desorbed without changing the chemical composition (this also occurs with decreasing pressure).

Chemical adsorption (chemisorption).

The disadvantage of chemisorption is that in this case it is irreversible, the chemical composition of the adsorbate changes. As an adsorbate, choose ... Adsorbents can be both simple and complex oxides (activated ...

Section 4. Theoretical foundations for the protection of the hydrosphere and soil

Topic 11. Theoretical foundations for the protection of the hydrosphere

Industrial waste water

According to the nature of pollution, industrial waste waters are divided into acid-alkaline, containing heavy metal ions, chromium-, fluorine-, and cyan-containing. Acid-alkaline wastewater is formed from the processes of degreasing, chemical etching, applying various coatings.

Reagent method

At the stage of pre-treatment of wastewater, various oxidizing agents, reducing agents, acids and alkaline reagents are used, both fresh and ... Post-treatment of wastewater can be carried out on mechanical and carbon filters. …

Electrodialysis.

With this method, wastewater is treated electrochemically using chemical reagents. The quality of purified water after electrodialysis can be close to distilled. It is possible to purify waters with a variety of chemical contaminants: fluoride, chromium, cyanides, etc. Electrodialysis can be used before ion exchange to maintain a constant salinity of water, during the regeneration of waste solutions and electrolytes. The disadvantage is a significant consumption of electricity. Commercially available electrodialysis units such as EDU, ECHO, AE, etc. are used. (capacity from 1 to 25m 3 /h).

Water purification from oil products

international convention 1954 (as amended 1962, 1969, 1971) for the Prevention of Marine Pollution by Oil established a ban on the discharge of bilge and ballast water containing oil products overboard within the coastal zone (up to 100-150 miles) with a concentration of more than 100 mg / l). In Russia, the following maximum permissible concentrations (MPCs) of oil products in water have been established: high-sulfur oil products - 0.1 mg/l, non-sulphurous oil products - 0.3 mg/l. In this regard, the development and improvement of methods and means of water purification from oil products contained in it is of great importance for environmental protection.

Methods of purification of oily waters.

_Coalescence. This is the process of particle enlargement due to their merging. Enlargement of oil particles can take place spontaneously when they ... Some increase in the rate of coalescence can be obtained by heating ... Coagulation. In this process, particles of petroleum products are coarsened when various ...

Topic 12. Theoretical foundations of soil protection

The theoretical foundations of soil protection include, among other things, the issues of the movement of contaminants in the soil for regions with different… The model of the distribution of contaminants in the soil

Rice. 14. Types of waste disposal

a - dump type of burial; b - burial on the slopes; in - burial in pits; G - burial in an underground bunker; 1 - waste; 2 - waterproofing; 3 - concrete

Disadvantages of dump type burials: difficulty in assessing the stability of slopes; high shear stresses at the base of slopes; the need to use special building structures to increase the stability of the burial; aesthetic load on the landscape. Burials on the slopes in contrast to the considered dump-type burials, they require additional protection of the burial body from slipping and from being washed away by water flowing down the slope.
Burial in pits has less impact on the landscape and does not pose a sustainability hazard. However, it requires the removal of water using pumps, since the base is located below the surface of the earth. Such disposal creates additional difficulties for waterproofing the side slopes and the base of the waste disposal site, and also requires constant monitoring of drainage systems.
Burials in underground bunkers in all respects more convenient and environmentally friendly, however, due to the high capital costs of their construction, they can only be used to remove small amounts of waste. Underground burial is widely used for isolation radioactive waste, as it allows, under certain conditions, to ensure radioecological safety for the entire required period and is the most economical effective way dealing with them. Waste should be deposited at the landfill in layers no thicker than 2 m, with obligatory compaction to ensure the greatest compactness and absence of voids, which is especially important when burying bulky waste.
Compaction of waste during disposal is necessary not only to maximize the use of free space, but also to reduce the subsequent settling of the burial body. In addition, a loose burial body having a density below 0.6 t/m makes it difficult to control the leachate, since many channels inevitably appear in the body, making it difficult to collect and remove it.
However, sometimes, primarily for economic reasons, the storage is filled section by section. The main reasons for section filling are the need to separate various types waste within the same landfill, as well as the desire to reduce the area on which the leachate is formed.
When assessing the stability of a burial body, one should distinguish between external and internal stability. Internal stability is understood as the state of the burial body itself (stability of the sides, resistance to swelling); external stability is understood as the stability of the burial ground (subsidence, crushing). Lack of stability can damage the drainage system. The objects of control at the landfills are air and biogas, groundwater and leachate, soil and the burial body. The scope of monitoring depends on the type of waste and the design of the landfill.

Requirements for landfills: prevention of impact on the quality of ground and surface waters, on the quality of the air environment; prevention of the negative impact associated with the migration of pollutants into the underground space. In accordance with these requirements, it is necessary to provide: impermeable soil and waste covers, leakage control systems, maintenance and control of the landfill after closure, and other appropriate measures.

Basic elements of a safe landfill: a layer of surface soil with vegetation; drainage system along the edges of the landfill; an easily permeable layer of sand or gravel; an insulating layer of clay or plastic; waste in compartments; fine soil as the basis for an isolating word; ventilation system to remove methane and carbon dioxide; drainage layer for liquid drainage; lower insulating layer to prevent seepage of contaminants into groundwater.

Bibliography.

1. Eremkin A.I., Kvashnin I.M., Junkerov Yu.I. Rationing of emissions of pollutants into the atmosphere.: tutorial- M., ed. ASV, 2000 - 176 p.

2. Hygienic standards "Maximum Permissible Concentrations (MPC) of pollutants in the atmospheric air of populated areas" (GN2.1.6.1338-03), with Additions No. 1 (GN 2s.1.6.1765-03), Additions and changes No. 2 (GN 2.1.6.1983-05). Enacted by the Decrees of the Chief Sanitary Doctor of the Russian Federation No. 116 of May 30, 2003, No. 151 of October 17, 2003, No. 24 of November 3, 2005 (registered by the Ministry of Justice of Russia on June 9, 2003, reg. No. 4663; 10.21.2003 reg. No. 5187; 02.12.2005 reg. No. 7225)

3. Mazur I.I., Moldavanov O.I., Shishkov V.N. Engineering ecology, general course in 2 volumes. Under the general editorship. M.I. Masuria. - M.: Higher school, 1996. - v.2, 678 p.

4. Methodology for calculating the concentrations in the atmospheric air of harmful substances contained in the emissions of enterprises (OND-86). Decree of the USSR State Committee for Hydrometeorology dated 04.08.1986 No. 192.

5. CH 245-71. Sanitary standards design of industrial enterprises.

6. Uzhov V.I., Valdberg A.Yu., Myagkov B.I., Reshidov I.K. Purification of industrial gases from dust. -M.: Chemistry, 1981 - 302 p.

7. the federal law"On the Protection of Atmospheric Air" (as amended on December 31, 2005) dated May 4, 1999 No. 96-FZ

8. Federal Law "On Environmental Protection" dated 10.01.2002 No. 7-FZ (as amended on December 18, 2006)

9. Khudoshina M.Yu. Ecology. Laboratory workshop UMU GOU MSTU "STANKIN", 2005. Electronic version.

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1. General principles for the dispersion of pollutants in the atmosphere.

2. Mechanism for calculating the dispersion of harmful emissions from industrial enterprises.

3. Theory of NO x formation during fossil fuel combustion.

4. The theory of the formation of sooty particles during the combustion of fossil fuels.

5. The theory of the formation of gas-formed underburning in boiler furnaces.

6. The theory of SO x formation during fossil fuel combustion.

7. Reduced NO x emissions.

8. Reducing the emission of SO x.

9. Reduced aerosol emissions.

10. Basic principles of the transfer of pollution in the atmosphere.

11. Influence of thermophysical and aerodynamic factors on the processes of heat and mass transfer in the atmosphere.

12. Basic provisions of the theory of turbulence from classical hydrodynamics.

13. Application of the theory of turbulence to atmospheric processes.

14. General principles of dispersion of pollutants in the atmosphere.

15. Spread of pollutants from the pipe.

16. Basic theoretical approaches used to describe the processes of dispersion of impurities in the atmosphere.

17. Calculation method for the dispersion of harmful substances in the atmosphere, developed in GGO them. A.I. Voeikov.

18. General patterns of dilution of wastewater.

19. Methods for calculating the dilution of wastewater for watercourses.

20. Methods for calculating the dilution of wastewater for reservoirs.

21. Calculation of the maximum allowable discharge for flowing water bodies.

22. Calculation of the maximum allowable discharge for reservoirs and lakes.

23. The movement of aerosol pollutants in the stream.

24. Theoretical foundations for capturing solid particles from exhaust gases.

25. Theoretical foundations of environmental protection from energy impacts.

Literature

1. Kulagina T.A. Theoretical foundations of environmental protection: Textbook. allowance / T.A. Kulagin. 2nd ed., revised. And extra. Krasnoyarsk: IPTs KSTU, 2003. - 332 p.

Compiled by:

T.A. Kulagina

Section 4. ENVIRONMENTAL IMPACT ASSESSMENT AND Ecological Expertise

1. The system of environmental assessment, the subject, goals and main objectives of the course and the concept of the course, types of environmental assessments. Differences between environmental expertise (EE) and environmental impact assessment (EIA).

2. Development of the system of environmental support of the project, the life cycle of the project, ESHD.

3. Environmental support economic activity investment projects (differences in approaches, categories).

4. Legal and regulatory - methodological base environmental expertise and EIA in Russia.

5. Classification of EE and EIA objects by types of nature management, by type of matter and energy exchange with the environment, by degree environmental hazard for nature and man, according to the toxicity of substances.

6. Theoretical foundations of environmental expertise (goals, objectives, principles, types and types of state environmental expertise, interaction matrix).

7. Subjects and objects of state environmental expertise.

8. Methodological provisions and principles of environmental design ..

9. The procedure for organizing and conducting environmental procedures (grounds, case, conditions, aspects, procedure for the State Environmental Expertise and its regulations for conducting).

10. List of documentation submitted for state environmental expertise (on the example of the Krasnoyarsk Territory).

11. The procedure for preliminary consideration of documentation submitted to the SEE. Registration of the conclusion of the state ecological expertise (composition of the main parts).

13. Public ecological expertise and its stages.

14. Principles of environmental assessment. The subject of environmental assessment.

15. Regulatory framework for environmental assessment and specially authorized bodies (their functions). Participants in the environmental assessment process, their main tasks.

16. Stages of the environmental assessment process. Methods and systems for selecting projects.

17. Methods for identifying significant impacts, matrices for identifying impacts (schemes).

18. The structure of the EIA and the method of organizing the material, the main stages and aspects.

19. Environmental requirements for the development of regulations, environmental criteria and standards.

20. Standards for environmental quality and permissible impact, use of natural resources.

21. Rationing of sanitary and protective zones.

22. Information base of ecological design.

23. Public participation in the EIA process.

24. Assessment of the impact of the investigated economic facility on the atmosphere, direct and indirect criteria for assessing atmospheric pollution.

25. Procedure for conducting EIA (stages and procedures of EIA).

Literature

1. Law of the Russian Federation "On the Protection of the Environment" dated January 10, 2002 No. 7-FZ.

2. Law of the Russian Federation "On Ecological Expertise" dated November 23, 1995 No. 174-FZ.

3. Regulation “On Environmental Impact Assessment in the Russian Federation”. / Approved Order of the Ministry of Natural Resources of the Russian Federation of 2000 No.

4. Guidelines for the environmental review of pre-project and project documentation. / Approved. Head of Glavgosekoekspertiza dated 10.12.93. Moscow: Ministry of Natural Resources. 1993, 64 p.

5. Fomin S.A. "State Ecological Expertise". / In the book. Environmental law of the Russian Federation. // Ed. Yu.E. Vinokurov. - M.: Publishing house of MNEPU, 1997. - 388 p.

6. Fomin S.A. "Ecological Expertise and EIA". / In the book. Ecology, nature protection and ecological safety. // Under the general editorship. IN AND. Danilova-Danilyana. - M.: Publishing House of MNEPU, 1997. - 744 p.

Compiled by:

Candidate of Technical Sciences, Associate Professor of the Department of Engineering Ecology

and life safety"

Man has had an impact on the environment since ancient times. The constant economic development of the world improves human life and expands it natural environment habitats, but the condition of limited natural resources and physical capabilities remains unchanged. The creation of specially protected areas, the ban on hunting and deforestation are examples of restrictions on such impacts that have been introduced since ancient times. However, it was only in the 20th century that the scientific substantiation of this impact, as well as the problems that arose as a result, and the development of a rational solution, taking into account the interests of the present and future generations, were born.

In the 1970s, many scientists devoted their work to the issues of limited natural resources and environmental pollution, emphasizing their importance for human life.

For the first time, the term "ecology" was used by the biologist E. Haeckel: "By ecology we mean the general science of the relationship between the organism and the environment, where we include all the" broad sense this word." ("General morphology of organisms", 1866)

The modern definition of the concept of ecology has a broader meaning than in the first decades of the development of this science. The classical definition of ecology is the science that studies the relationship between living and non-living things. http://www.werkenzonderdiploma.tk/news/nablyudaemomu-v-nastoyaschee-83.html

Two alternative definitions of this science:

· Ecology - the knowledge of the economy of nature, the simultaneous study of all the relationships of living things with organic and inorganic components of the environment ... In a word, ecology is a science that studies all the complex relationships in nature, considered by Darwin as conditions for the struggle for existence.

· Ecology is a biological science that studies the structure and functioning of superorganismal systems (populations, communities, ecosystems) in space and time, in natural and human-modified conditions.

Ecology in scientific works logically moved into the concept of sustainable development.

Sustainable development - ecological development- involves meeting the needs and aspirations of the present without undermining the ability of future generations to meet their needs. Transition to the era of sustainable development., R.A. flight, s. 10-31 // Russia in the surrounding world: 2003 (Analytical Yearbook). - M.: Publishing house MNEPU, 2003. - 336 p. http://www.rus-stat.ru/index.php?vid=1&id=53&year=2003 As this environmental concern has become greater over the past decades, concern for the fate of future generations and the fair distribution of natural resources between generations has become more and more evident.

Concept biodiversity- biodiversity - is interpreted as a variety of life forms, expressed through millions of species of plants, animals and microorganisms, together with their genetic fund and a complex ecosystem.

The maintenance of biodiversity is now a global need for at least three reasons. The main reason is that all species have the right to live in the conditions that are peculiar to them. Secondly, plural forms of life maintain the chemical and physical balance on Earth. Finally, experience shows that maintaining the maximum genetic stock is of economic interest to Agriculture and the medical industry.

Today, many countries are faced with the problem of environmental degradation and the need to prevent further development of this process. Economic development leads to environmental problems, causes chemical pollution, and damages natural habitats. There is a threat to human health, as well as the existence of many species of flora and fauna. The problem of limited resources is becoming more and more acute. Future generations will no longer have the natural resources that previous generations had.

To solve a number of environmental problems in European Union energy-saving technology is applied, in the USA the emphasis is on bioengineering. At the same time, developing countries and countries with economies in transition have not realized the importance of environmental impact. Often the solution of problems in these countries occurs under the influence of external forces, rather than government policy. This attitude can lead to a further widening of the gap between developed and developing countries, and, no less important, to increased environmental degradation.

Summing up, it should be noted that with economic development With the development of new technologies, the state of ecology is also changing, and the threat of environmental degradation is increasing. At the same time, new technologies are being created to solve environmental problems.

NOVOSIBIRSK STATE TECHNICAL UNIVERSITY

Department of Engineering Problems of Ecology

“I APPROVE”

Dean of the Faculty

aircraft

“___” ______________200

WORKING PROGRAM of the academic discipline

theoretical foundations of environmental protection

BEP in the direction of training a graduate

656600 - Environmental Protection

specialty 280202 "Engineering environmental protection"

Qualification - environmental engineer

Faculty of Aircraft

Course 3, semester 6

Lectures 34 hours.

Practical classes: 17 hours.

RGZ 6 semester

Independent work 34 hours

Exam 6 semester

Total: 85 hours

Novosibirsk

The work program is compiled on the basis of the State educational standard of higher professional education in the direction of training a graduate - 656600 - Environmental Protection and specialty 280202 - "Environmental Protection Engineering"

Registration number 165 tech \ ds dated March 17, 2000

Code of discipline in the State Educational Standard - SD.01

The discipline "Theoretical foundations of environmental protection" refers to the federal component.

Code of discipline according to the curriculum - 4005

The work program was discussed at a meeting of the Department of Engineering Problems of Ecology.

Minutes of the meeting of the department No. 6-06 of October 13, 2006

The program was developed

professor, doctor of technical sciences, professor

Department head

Professor, Doctor of Technical Sciences, Associate Professor

Responsible for the main

professor, doctor of technical sciences, professor

1. External requirements

General requirements for education are given in Table 1.

Table 1

GOS requirements for the mandatory minimum

disciplines	"Theoretical foundations of environmental protection"
	Theoretical foundations of environmental protection: physical and chemical foundations of wastewater and waste gas treatment processes and solid waste disposal. Processes of coagulation, flocculation, flotation, adsorption, liquid extraction, ion exchange, electrochemical oxidation and reduction, electrocoagulation and electroflotation, electrodialysis, membrane processes (reverse osmosis, ultrafiltration), sedimentation, deodorization and degassing, catalysis, condensation, pyrolysis, remelting, roasting , fire disposal, high-temperature agglomeration. Theoretical foundations of environmental protection from energy impacts. The principle of screening, absorption and suppression at the source. Diffusion processes in the atmosphere and hydrosphere. Dispersion and dilution of impurities in the atmosphere, hydrosphere. Dispersion and dilution of impurities in the atmosphere, hydrosphere. Calculation and dilution methods.

2. Goals and objectives of the course

The main goal is to familiarize students with the physical and chemical foundations of the neutralization of toxic anthropogenic waste and master the initial skills of engineering methods for calculating equipment for the neutralization of these wastes.

3. Requirements for the discipline

The basic requirements for the course are determined by the provisions of the State Educational Standard (SES) in the direction 553500 - environmental protection. In accordance with the GOS for the specified direction, the following main sections are included in the work program:

Section 1. The main pollutants of the environment and methods for their neutralization.

Section 2. Fundamentals of calculation of adsorption, mass transfer and catalytic processes.

4. Scope and content of the discipline

The volume of the discipline corresponds to the curriculum approved by the vice-rector of NSTU

The name of the topics of lectures, their content and volume in hours.

Section 1. The main environmental pollutants and methods for their neutralization (18 hours).

Lecture 1. Anthropogenic pollutants of industrial centers. Pollutants of water, air and soil. Formation of nitrogen oxides in combustion processes.

Lecture 2. Fundamentals of calculating the dispersion of impurities in the atmosphere. Coefficients used in impurity dispersion models. Examples of impurity dispersion calculation.

Lectures 3-4. Methods for cleaning industrial gas emissions. The concept of cleaning methods: absorption, adsorption, condensation, membrane, thermal, chemical, biochemical and catalytic methods for neutralizing pollutants. Areas of their application. Main technological features and process parameters.

Lecture 5. Wastewater treatment based on separation methods. Wastewater treatment from mechanical impurities: settling tanks, hydrocyclones, filters, centrifuges. Physico-chemical bases for the use of flotation, coagulation, flocculation to remove impurities. Methods of intensification of wastewater treatment processes from mechanical impurities.

Lecture 6. Regeneration methods of wastewater treatment. The concept and physical and chemical bases of methods of extraction, stripping (desorption), distillation and rectification, concentration and ion exchange. The use of reverse osmosis, ultrafiltration and adsorption for water purification.

Lectures 7-8. Destructive methods of water purification. The concept of destructive methods. The use of chemical methods for water purification based on the neutralization of acidic and alkaline pollutants, the reduction and oxidation (chlorination and ozonation) of impurities. Purification of water by transferring pollutants into insoluble compounds (precipitation). Biochemical wastewater treatment. Features and mechanism of the cleaning process. Aerotanks and digesters.

Lecture 9. Thermal method for the neutralization of wastewater and solid waste. Technological scheme of the process and types of equipment used. The concept of fire disposal and pyrolysis of waste. Liquid-phase oxidation of waste - the concept of the process. Features of activated sludge processing.

Section 2 Fundamentals of calculation of adsorption, mass transfer and catalytic processes (16 hours).

Lecture 10. Main types of catalytic and adsorption reactors. Shelf, tubular and fluidized bed reactors. Areas of their application for the neutralization of gas emissions. Designs of adsorption reactors. Use of moving layers of adsorbent.

Lecture 11. Fundamentals of calculation of gas emission neutralization reactors. The concept of reaction rate. Hydrodynamics of fixed and fluidized granular layers. Idealized reactor models - ideal mixing and ideal displacement. Derivation of material and heat balance equations for ideal mixing and ideal displacement reactors.

Lecture 12. Processes on porous adsorbent and catalyst granules. Stages of the process of chemical (catalytic) transformation on a porous particle. Diffusion in a porous particle. Molecular and Knudsen Diffusion. Derivation of the material balance equation for a porous particle. The concept of the degree of use of the inner surface of a porous particle.

Lectures 13-14. Fundamentals of adsorption processes. Adsorption isotherms. Methods for experimental determination of adsorption isotherms (weight, volumetric and chromatographic methods). Langmuir adsorption equation. Mass and heat balance equations for adsorption processes. Stationary sorption front. The concept of equilibrium and non-equilibrium adsorption Examples practical application and calculation of the adsorption process for gas purification from benzene vapors.

Lecture 15. The mechanism of mass transfer processes. Mass transfer equation. Equilibrium in the "liquid-gas" system. Henry and Dalton equations. Schemes of adsorption processes. Material balance of mass transfer processes. Derivation of the equation of the working line of the process. Driving force mass transfer processes. Determination of the average driving force. Types of adsorption apparatuses. Calculation of adsorption apparatuses.

Lecture 16. Purification of exhaust gases from mechanical pollutants. mechanical cyclones. Calculation of cyclones. Choice of types of cyclones. Estimated determination of dust collection efficiency.

Lecture 17. Fundamentals of gas purification using electrostatic precipitators. Physical bases of trapping mechanical impurities by electrostatic precipitators. Calculation equations for evaluating the efficiency of electrostatic precipitators. Fundamentals of designing electrostatic precipitators. Methods for improving the efficiency of trapping mechanical particles by electrostatic precipitators.

Total hours (lectures) - 34 hours.

The name of the topics of practical classes, their content and volume in hours.

1. Methods for cleaning gas emissions from toxic compounds (8 hours), including:

a) catalytic methods (4 hours);

b) adsorption methods (2 hours);

c) gas cleaning with cyclones (2 hours).

2. Fundamentals of calculation of reactors for gas neutralization (9 hours):

a) calculation of catalytic reactors based on models of ideal mixing and ideal displacement (4 hours);

b) calculation of adsorption apparatus for gas purification (3 hours);

c) calculation of electrostatic precipitators for capturing mechanical pollutants (2 hours).

________________________________________________________________

Total hours (practical exercises) - 17 hours

The name of the topics of settlement and graphic tasks

1) Determination of the hydraulic resistance of a fixed granular catalyst bed (1 hour).

2) Study of the modes of fluidization of granular materials (1 hour).

3) Study of the process of thermal treatment of solid waste in a fluidized bed reactor (2 hours).

4) Determination of the adsorption capacity of sorbents to capture gaseous pollutants (2 hours).

________________________________________________________________

Total (settlement and graphic tasks) - 6 hours.

4. Forms of control

4.1. Protection of settlement and graphic tasks.

4.2. Protection of abstracts on the topics of the course.

4.3. Questions for the exam.

1. Fundamentals of absorption gas purification processes. types of absorbers. Fundamentals of calculation of absorbers.

2. Designs of catalytic reactors. Tubular, adiabatic, with a fluidized bed, with radial and axial gas flow, with moving layers.

3. Distribution of emissions from pollution sources.

4. Adsorption processes for gas purification. Technological schemes of adsorption processes.

5. Wastewater treatment by oxidation of impurities with chemical reagents (chlorination, ozonation).

6. Diffusion in a porous granule. Molecular and Knudsen diffusion.

7. Conditioning methods of gas purification.

8. Thermal treatment of solid waste. Types of neutralization furnaces.

9. The equation of the ideal mixing reactor.

10. Membrane methods of gas purification.

11. Hydrodynamics of fluidized granular layers.

12. Conditions of fluidization.

13. Fundamentals of capturing aerosols by electrostatic precipitators. Factors affecting their performance.

14. Thermal neutralization of gases. Thermal neutralization of gases with heat recovery. Types of thermal treatment furnaces.

15. Fundamentals of the processes of extraction wastewater treatment.

16. Model of a plug-flow reactor.

17. Fundamentals of chemical methods of gas purification (irradiation of electron flows, ozonation)

18. Hydrodynamics of immobile granular layers.

19. Equilibrium in the "liquid - gas" system.

20. Biochemical purification of gases. Biofilters and bioscrubers.

21. Biochemical purification - the basics of the process. Aerotanks, metatanks.

22. Idealized models of catalytic reactors. Material and heat balances.

23. Types of wastewater pollutants. Classification of cleaning methods (separation, regenerative and destructive methods).

24. Front of adsorption. equilibrium adsorption. Stationary adsorption front.

25. Dust collecting equipment - cyclones. Cyclone calculation sequence.

26. Methods for separating mechanical impurities: settling tanks, hydrocyclones, filters, centrifuges).

27. Concentration - as a method of wastewater treatment.

28. Front of adsorption. equilibrium adsorption. Stationary adsorption front.

29. Fundamentals of flotation, coagulation, flocculation.

30. Heat (mass) exchange during adsorption.

31. The sequence of calculation of the packed absorber.

32. Physical basis for the intensification of wastewater treatment processes (magnetic, ultrasonic methods).

33. Processes of transformation on a porous particle.

34. The sequence of calculations of adsorbers.

35. Desorption - a method of removing volatile impurities from wastewater.

36. Adsorption wastewater treatment.

37. The concept of the degree of use for catalyst particles.

38. Distribution of emissions from pollution sources.

39. Distillation and rectification in wastewater treatment.

40. Non-equilibrium adsorption.

41. Reverse osmosis and ultrafiltration.

42. Isotherms of adsorption. Methods for determining adsorption isotherms (weight, volume, chromatographic).

43. Fundamentals of liquid-phase oxidation of wastewater under pressure.

44. The driving force of mass transfer processes.

45. Wastewater treatment by neutralization, recovery, precipitation.

46. ​​Equations of thermal and material balance of an adsorber.

47. Dust collecting equipment - cyclones. Cyclone calculation sequence.

48. Biochemical purification - the basics of the process. Aerotanks, metatanks.

49. Fundamentals of capturing aerosols with electrostatic precipitators. Factors affecting their performance.

1. Equipment, facilities, fundamentals of designing chemical-technological processes, protection of the biosphere from industrial emissions. M., Chemistry, 1985. 352p.

2. . . Maximum Permissible Concentrations chemical substances in the environment. L. Chemistry, 1985.

3. B. Bretschneider, I. Elector. Protection of the air basin from pollution. L. Chemistry, 1989.

4. . Neutralization of industrial emissions by afterburning. M. Energoatomizdat, 1986.

5. et al. Industrial wastewater treatment. M. Stroyizdat, 1970, 153s.

6. et al. Purification of industrial wastewater. Kyiv, Technique, 1974, 257p.

7. , . Waste water treatment in the chemical industry. L, Chemistry, 1977, 464p.

8. AL. Titov, . Neutralization industrial waste: M. Stroyizdat, 1980, 79s.

nine. , . The impact of thermal power plants on the environment and ways to reduce the damage. Novosibirsk, 1990, 184p.

ten. . Theoretical foundations of environmental protection (lecture notes). IK SB RAS - NSTU, 2001 - 97s.