1. SOURCES OF SOLID WASTE: Wastewater. Gas emissions
Lecture № 4
SOURCES OF SOLID WASTE:
Wastewater.
Gas emissions

2. The main sources of waste water
industry
enterprises of household purpose;
large livestock facilities;
large agricultural complexes;
waste of the deposits mining;
mines and quarries water;
processing and alloy products;
discharges of water and rail transport;
primary flax processing waste, etc.

3. Состав и происхождение сточных вод
Composition and sources of wastewater
Состав и происхождение сточных вод
Types of wastewater
The qualitative composition
Phase Composition
ATMOSPHERIC (storm)
solids
petroleum products,
fertilizers
Suspended substanses
organic matter (60%),
minerals (40%),
microorganisms and bacteria
colloids
Domestic or municipal
Solutions of organic compounds
solids
Mineral oil and petroleum products,
inorganic acids and their salts,
alkali, surfactants
heavy metal ions
Ionic solutions
INDUSTRIAL (depend on enterprises)

4. Types of wastewater pollution
Mechanical - high content of mechanical impurities, mainly for surface water;
Chemical - toxic and non-toxic organic and inorganic (mineral) substances: acids, bases, salts (arsenic, lead, cadmium, mercury, chromium, copper, fluoride), hydrocarbons of various structures and their derivatives - more than 1 million substances
Bacterial and biological - the presence of organic matter in the water ( Mt. / year), surfactants, nutrients, a variety of pathogenic microorganisms, fungi and small algae.
Radioactive - the presence of radioactive substances in surface water or groundwater;
Heat - heated water of thermal and nuclear ES, industrial wastewater

5. Industrial wastewater
formed as a result of water use in various industrial processes and depend on the enterprise
The main (foreground) pollutants:
mechanical suspension (sand, scale, metal shavings, dust, fluxes, cotton fiber, etc.);
mineral oils and other petroleum products;
inorganic acids and their salts;
alkali;
surface-active agents (surfactants);
inorganic salts of heavy metals.

6. Atmospheric sewage or runoff
formed from runoff of the rain and snowmelt from an area directly into the water bodies or sewage system.
Composition varied:
solids (sand, stones, chips, dust, soot, crop residues, etc.)
petroleum products, fertilizers, etc.
Particularity - low concentrations of pollutants (except HD)

7. Domestic wastewater or municipal wastewater
formed in the process of human life,
Have a relatively constant composition:
contain about 60% of organic matter,
about 40% of minerals,
predominant types of microorganisms: Escherichia coli, Salmonella, Staphylococcus, Streptococcus, Enterococcus, Clostridium, Enteroviruses

8. The content of organic substances in industrial wastewater
Pollutants
Amount
in the world's stock
Mt. / year
Oil products
26,563
Phenols
0,460
Waste of synthetic fibers
5,500
Plant fossils
0,170
In total
33,273

9. Chemical contaminants of industrial effluents
biologically labile organic compounds;
low toxic inorganic salts;
oil and oil products;
biogenic compounds;
substances with specific toxic properties, including heavy metals;
biologically hardly decomposed (or nondecomposed) organic synthetic compounds.

10. The most dangerous and most widespread types of chemical contaminants
1. Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic, chromium, nickel, cobalt, manganese, antimony, tin, bismuth) - persistent chemical contaminants have got cumulative effect of the specific toxic properties
Heavy metals
ENVIRONMENT
COMPONENTS +
Connectivity conditions: t, nature of the metal, pH, ionic forms
Complexes
Oxyhydrates
Synergistic mixtures
Hydrated ions
Ion pairs

11. The most dangerous and most widespread types of chemical contaminants
2.Oil and petroleum products, metalworking fluids coolant - the main chemical contaminants in the land waters, waters of seas and oceans, 6.1 million tons annually
Danger: they have an ability to form stable colloidal systems like micelles
Oil globule
Na+
dipole emulsifier R-CH2-COO)+Н-

12. Modern methods of sewage treatment against industrial pollution
Wastewater treatment - destruction or removal of the hazardous substances.
Destructive methods: the destruction of contaminants or transformation into non-toxic products and the removal of sediments in the insoluble form  
Regenerative methods: based on extraction and utilization of impurities.
Wastewater treatment can be considered as complex, multi-stage manufacturing process cause it:
uses raw materials (waste water)
has finished products (purified water)
has waste products (precipitation).

13. Modern methods of sewage treatment (according to the mechanism of action)
Biological: filtering fields, biological ponds, aeration, methane tanks, aerotanks, biofilters,
Physical: magnetic, ultrasonic, Electro treatment, ionizing radiation
Physicochemical: coagulation, floatation, adsorption, ion exchange, extraction, distillation, freezing, electrodialysis, reverse osmosis
Sewage treatment
Mechanical: settling, filtering, centrifugation, filtration, microfiltration, cleaning in hydrocyclones
Chemical: oxidation (chlorination, ozonation, liquid-phase and vapor-phase oxidation), reduction, neutralization, precipitation, complexation

14. Mechanical methods
Removes mechanical impurities (coarsely dispersed particles), depending on the size:
 by grilles, screens, sand traps, septic tanks, manure traps of different designs;
surface pollution – by oil traps, petrole traps, sumps, etc.
allows to select up to 60-75% of insoluble impurities from the municipal sewage, and from industry sewage - up to 95%

15. Chemical (reagent) methods
Purpose - precipitation in the form of insoluble substances: Processes: oxidation, reduction, neutralization Advantages: allow to achieve the efficiency up to 95% of soluble and 25% of insoluble impurities

16. Physicochemical methods
Advantages:
remove fine particles and dissolved inorganic impurities;
organic matter and hardly oxidizable substances are broken down
Apply: electrocoagulation, sorption, extraction, ion exchange, electrofloatation, galvanic coagulation

17. Floatation (flocculation)
Used to treat wastewater from the rough and fine impurities and condensation of suspensions with fine phase.
Principle: The formation of particle-bubble complex, bubbles floating and removing of the foam layer containing impurities from the water surface.
Advantages: remove fine and colloidal impurities with the help of coagulants and flocculants.

18. Reverse osmosis (hyperfiltration)
the process of the solution separating by filtration through a membrane: pore diameter of about 1 nm pass through water molecules but is impermeable or semi-permeable to hydrated salt ions or undissociated molecules
Advantages:
selectivity of the membranes;
efficiency - up to 99%;
provides clean water that can be returned to the water recirculation system

19. R’H + Na+  R’Na + H+; R’’OH + Cl-  R’’Cl + OH- ,
Ion exchange
Apply: for deep purification of industrial water from heavy metal ions (desalting) and for local systems of metals recovering;
Advantages: in some cases can return considerable pert of the water into the work cycle;
Ion exchange materials (resins): insoluble polyelectrolytes react (exchange) with the ions of the solution:
R’H + Na+  R’Na + H+; R’’OH + Cl-  R’’Cl + OH-  ,
where R’ and R’’ - solid organic matrix (polystyrene) with cation and anion, respectively; Na+, H+, Cl-, OH- - exchanging mobile ions.

20. Regenerating solution
The scheme of an ion exchange plant № 1, 2, 3 - valves, 4 - tank with regenerating solution
Wastewater
Regenerating solution
Grille and resin layer 1 2 3 4
Pump
Working solution

21. Adsorption method
the most affordable and effective method of deep cleaning (post-treatment) of the dissolved organic matter.
Applied active sorbents: fine substances with a developed surface - sawdust, ash, peat, clay, coke breeze, activated carbons.

22. Municipal sewage (domestic waste water)
contain large amounts of:
synthetic detergents (surfactants);
oils and fats,
nitrate and nitrite,
phosphorus, chloride and sulfate,
 vegetable fibers,
 faecal matter,
food waste.

23. Methods for biological treatment of municipal wastewater
Microorganisms
Cleaning equipment
Airotanks, methane tanks
Anaerobic digestion
Bacteria
Activated sludge (silt)
Biotanks, submerged biofilters
Aerobic oxidation
Protozoa
Biofilm
COMPOSITION AND PROPERTIES
Biofilters
Activated sludge (silt): colloidal system, pH 4 - 9, the negative charge
Biofilms: mucous fouling thickness of mm
Biocenosis of: bacteria, fungi, yeast
Biocenosis of: bacteria, worms, fungi, yeasts, algae - in total about 12 species, solid substrate
General chemical composition of the sludge: C54H212O82N8S7

24. Agricultural wastewater and livestock enterprises
Contain about 60% of organic origin, including:
biological contaminants (bacteria, viruses, fungi, algae);
pesticides, herbicides, insecticides;
chemical fertilizers;
Insecticides in the form of suspensions, dissolved in the oil

25. Classification of gas emissions based on the aggregative state
SOLID
carcinogens,
heavy metals & their compounds
organic and inorganic dust
soot, tarry materials
GASEOUS:
sulfur dioxide, oxides of nitrogen & carbon, hydrocarbons
LIQUID
Solutions of acid,
alkalis, salts

26. Amount of gas and dust emissions on a global industry
Brunch of industry
Emisssion, %
Energy (thermal power plant)
43,0
Ferrous and nonferrous metallurgy
23,1
Refining industry
10,8
Other brunches

27. Methods of the air protection
1. Prevention of harmful contaminants and their introduction into the ambient air.
2. Cleaning of the air-gas emissions: mechanical, chemical, physical and chemical.
3. Creation of buffer zones around industrial enterprises

28. Methods for cleaning of gas & dust emissions from aerosols
1. Mechanical cleaning by dry and wet methods:
dry - gravitational settling, inertial and centrifugal dust removal, filtration;
wet - centrifugal scrubbers, foam scrubbers, Venturi scrubbers

29. Gravitational settling
dust-filled
gas 1
processed gas 2 2
Hollow chamber (long tube or corrugated sleeve) for the deposition of dust: 1 - body, 2 - tanks with hose to remove dust

30. 1-socket, 2-inner cylinder, 3-outer cylinder, 4 – tank for the dust.
Purified gas
Polluted stream \ 2 1 3 4
dust
Construction of cylindrical cyclone:
1-socket, 2-inner cylinder, 3-outer cylinder, 4 – tank for the dust.

31. "Wet" cleaning of gas and dust emissions from aerosols
liquid
gas
liquid
liquid
gas
gas
Sludge
Sludge
Sludge
Scheme of the main ways of dust collection in the wet scrubber:
a - in the volume of liquid, b – by a film of liquid, c – by sprayed liquid
1 - gas bubbles, 2 - liquid drops 3 - solids

32. Physico-chemical treatment of gas and dust emissions from gaseous impurities
Chemisorption, adsorption, catalytic and
thermal oxidation
Absorbents: water solutions of ammonia, carbonates and caustic alkalis, manganese salts, ethanolamines, oil slurry of calcium hydroxide, magnesium sulfate etc.
Purified flow
Аbsorbent 2
Contaminated
flow 1
Retraction to the recovery or recycling
Scheme of absorber:
  1 - the case of the absorber; 2 - mesh with nozzles