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8/10/2019 Avantaje Si Dezav

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Avantaje si dezav

Distillation Removes a broad

range of

contaminants and

therefore useful asa first purification

step.

Reusable

Contaminants are

carried to some extent

into the condensate.

Requires careful

maintenance to

ensure purity.

Consumes large

amounts of tap water

(for cooling) and

electrical energy (for

heating).

Not environment-friendly.

Ion Exchange Removes

dissolved

inorganics (ions)

effectively

allowing resistivity

levels above !".#

$%&cm ' *C tobe reached

(corresponding

roughly to less

than ! ppb total

ionic

contamination in

water).

Regenerable (by

acid and bases in

+service

deioni,ation or by

electrodeioni,ation

).

Relatively

inexpensive initial

capital investment.

imited capacity/

once all ion binding

sites are occupied

ions are no longer

retained (except when

operating in an

electodeioni,ationprocess).

0oes not effectively

remove organics

particles pyrogens or

bacteria.

Chemically

regenerated 01 beds

can generate organics

and particles.

2ingle use +virgin

resins require good

pretreated water

quality to be

economically efficient.


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Activated Carbon Removes

dissolved organics

and chlorine

effectively.

ong life due to

high binding

capacity.

MicroporousFilters

2creen filters are

absolute filters that

remove all

particles andmicroorganisms

greater than their

pore si,e.

3fficient operation

throughout their

lifetime unless

they are damaged.

$aintenance is

limited to

replacement.

hey will clog when the

surface is covered by

contaminants.

4herefore theyshould be used as a

last purification step

as a type of

insurance.

5ill not remove

dissolved inorganics

organics or pyrogens.

Not regenerable.

Ultrafiltration 3ffectively

removes most

particles

pyrogens

en,ymes

microorganismsand colloids above

their rated si,e

retaining them

above the

ultrafilter surface.

3fficient operation

throughout their

lifetime unless

they are damaged.

4heir lifetime can

5ill not remove

dissolved inorganics

or organic

substances.

$ay clog when

challenged by anexcessive level of

high-molecular-weight

contaminants.

0oes not efficiently

remove ions and

particulates.

imited capacity due

to a high but limited

number of binding

sites.

Can generate carbon

fines.


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be extended by a

regular water flush

at high speed.

Reverse Osmosis 3ffectively

removes all types

of contaminants to

some extent

(particles

pyrogens

microorganisms

colloids and

dissolved

inorganics) and istherefore useful as

a first purification

step.

Requires minimal

maintenance.

6peration

parameters

(pressure

temperature flow

rate ionic

re7ection) are easy

to monitor.

1mited flow rates per

surface unit require

either large

membrane surfaces

or an intermediate

storage device to

satisfy user demand.

Requires good

pretreatment to avoid

rapid membranedamage by water

contaminants/ scaling

(CaC68 deposits on

the surface) fouling

(deposits of organics

or colloids on the

surface) or piercing

(R6 membrane cut by

hard particulates).

Elix ContinuousDeioniation

Removes

dissolved

inorganics

effectively

allowing resistivity

above

%&cm ' * to

be reached (which

corresponds to a

total ionic

contamination

level in water of

approximately #ppb).

3nvironment-

Removes only a

limited number of

charged organics.

Requires feed bygood quality water

(for instance reverse

osmosis-treated

water) for

economically efficient

operation.


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friendly/

& no chemical

regeneration

& no chemical

disposal

& no resin disposal

1nexpensive to

operate.

2afe/ no heating

element.

Ultraviolet !U"#

Radiation

3ffective saniti,ing

treatment.

6xidation of

organic

compounds (!"

nm and 9 nm) to

reach water 46C

levels below

ppb.

:hotooxidation of

organics is a polishing

step able to decrease

the 46C level only by

a limited value.

4he C6produced

during photooxidation

decreases the water;s

resistivity.

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