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III. Water TreatmentTopic 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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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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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

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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

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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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Water Treatment UnitsKinds

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

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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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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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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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Basic Water Treatment Technological Schemes

One Stage Technological Scheme without Reagent Treatment1 - 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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Basic Water Treatment Technological Schemes

Two Stages Technological Scheme: Reagent Treatment

with Settlers1 - 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

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Basic Water Treatment Technological Schemes

Two Stages Technological Scheme: Reagent Treatment

with Upflow Sludge Blanket Clarifiers1 - 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

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Basic Water Treatment Technological Schemes

Two Stages Technological Scheme: Reagent Treatment

with Contact (Send) Clarifiers1 - 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