This document discusses various methods, processes, technologies, units and schemes for water treatment. It describes basic methods like clarification, decolorization and disinfection. Key processes mentioned are precipitation, clarification, filtration and coagulation/flocculation. Common treatment units include settlers, screens, filters and chlorination equipment. Both one and two stage treatment schemes are presented, with and without chemical reagents. The goal of water treatment is to remove contaminants and regulate water quality for its end use.

1. III. Water Treatment
Topic III.1. Methods, Processes, Technologies
and Units for Water Treatment
They depend on the coarse water quality and the water use requirements.
Basic Methods for Water Treatment
 Clarification
 For turbidity removal
 Decolourization
 For colour removal
 Organoleptic improvement
 For taste and smelt removal
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2. Basic Methods for Water Treatment
 Water chemical content regulation
 For dissolved substances regulation
(CO2, Fe+2, Mn-, HCO3
-, Mg-, Cl-, F-, O2)
 Disinfection
 For bacteria removal
 Desalination
 For potable water production from sea water
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3. Basic Processes for Water Treatment
 Precipitation
 For coarse suspended solids removal
 Clarification
 For fine suspended solids removal
 Filtration
 For fine suspended and colloidal particles removal
 Ultra-filtration/Inverted osmosis
 For sea water desalination
 For molecular screening
 Coagulation/Contact coagulation/Flocculation
 For colloidal impurities removal
 For send filtration enhancement 3

4. Basic Processes for Water Treatment
 Chlorination
 For disinfection
 For decolourization
 For organics removal
 For ammonia removal
 Chemical treatment
 For fine and colloidal particles removal
 For dissolved substances regulation
 Ion exchange
 For ion substances removal
 Aeration
 For dissolved oxygen supply and regulation
 Cooling
 For water temperature regulation 4

5. Basic Water Treatment Technologies
Classification
I. According to the degree of purification
 For deep purification
 For partial purification
II. According to chemicals usage
 With reagent treatment
 Without reagent treatment
III. According to technological stages
 One stage technological flowsheet (scheme)
 Two stages technological flowsheet (scheme)
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6. Water Treatment Units
Kinds
I. For clarification
 Settlers (Settling tanks)
 Separators
 Clarifiers
II. For screening
 Racks
 Macro-mash screens
 Micro-mash screens
III. For filtration
 High rate send filters
 Low rate send filters
 Carbon filters
 Multi-layers filter 6

7. Water Treatment Units
Kinds
IV. For reagent treatment
 Reservoirs (premises, vessels) for reagents keeping
 Reservoirs (vessels) for reagents solution preparing
 Equipment for reagents dosing
 Mixing chambers for reagents and water
 Reactors
 Flocculation chambers
 Upflow sludge blanket clarifiers
 Contact (send) clarifiers
 High rate send filters
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8. Water Treatment Units
V. For disinfecting
a) With chlorine
 Chlorine keeping vessels
 Chlorine dosing devices
 Chlorine regulation devices
b) With ozone
 Ozone generators
 Ozone dozing equipment
c) With ultraviolet rays
 Ultraviolet lamps
 Disinfecting reactors
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9. Water Treatment Units
VI. For water cooling
 Cooling towers
 Cooling basins
VII. For sea water desalination
 Ultra-filtering/Inverted osmosis membranes
 Ultra-filtering/Inverted osmosis units
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10. Basic Water Treatment Technological Schemes
One Stage Technological Scheme without Reagent Treatment
1 - inlet distributing chamber; 2 - flow meter; 3 - preliminary (coarse send) filter; 4 - low rate
send filter; reservoir for purified water; 6 - chlorination station
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11. Basic Water Treatment Technological Schemes
Two Stages Technological Scheme: Reagent Treatment
with Settlers
1 - inlet distributing chamber; 2 - flow meter; 3 - reactor (for taste and smelt removal);
4 - chorizontal mixing chamber; 5 - reacting chamber (for flocculation); 6 - horizontal settler;
7 - high rate send filter; 8 - reservoir for purified water; 9 - vessels for preparing of carbon
powder mixture; 10 - vessels for reagents; 11 - chlorination station 11

12. Basic Water Treatment Technological Schemes
Two Stages Technological Scheme: Reagent Treatment
with Upflow Sludge Blanket Clarifiers
1 - fine mesh-screens; 2 - inlet distribution chamber; 3 - flow meter; 4 - vertical mixing
chamber; 5 - upflow sludge blanket clarifier; 6 - high rate send filter; 7 - reservoir for
purified water; 8 - vessels for lime solution; 9 - vessels for coagulant solution; 10 - vessels
for flocculant solution; 11 - chlorination station 12

13. Basic Water Treatment Technological Schemes
Two Stages Technological Scheme: Reagent Treatment
with Contact (Send) Clarifiers
1 - inflow distribution chamber; 2 - flow meter; 3 - fine-mesh screens; 4 - mechanical-mixing
chamber; 5 - contact (send) clarifier; 6 - reservoir for purified water; 7 - vessels for
coagulant solution; 8 - vessels for fluorine; 9 - chlorination station 13