TYPE¥°: no detectable concentration of the compound or element to be analyzed at the detection limit of the analytical method
TYPE ¥²: washing and qualitative analysis
Water Purification Processes
Process
Dissolved
IonizedSolids
Dissolved
IonizedGases
Dissolved
Organics
Paticulates
Bacteria
Pyrogens
Distillation
G-E+
P
G
E
E
E
Deionization
E
E
P
P
P
P
Reverse osmosis
G¢Ô
P
G
E
E
E
Carbon adsorptioin
P
P¡×
G-E¡«
P
P
P
Filtration
P
P
P
E
E
P
Ultrafiltration
P
P
G#
E
E
G-E
Ultraviolet oxidation
P
P
G-E**
P
G++
P
E : Excellent(capable of complete or near total removal)
G : Good(capable of removing large percentages)
P : Poor(little or no removal)
+ :Resistivity of water purified by distillation is an order of magnitudeless than water produced by deionization, due mainly to the presende of CO2 and sometimes H2S, NH3, and other ionized gases if present in the feedwater
¢Ô : Resistivity of dissolved ionizedsolids depends on original feedwater resistivity
¡× : Activated carbon removes chlorine by adsorption.
¡«:When used in combination with other purification processes, special grades of activated carbon and other synthetic adsorbents exhibit excellent capabilities for removing organic contaminants. Their use, however is targeted toward specific compounds and applications.
# :Ultrafilter shave demon strated usefulness in reducing specific feed water or ganic contaminants based on the rated molecular weight cut-off of the membrane.
** : 185nm ultraviolet oxidation(batch process systems) is effective in removing trace organic contaminants when used as post-treatment. Feedwater makeup plays a critical role in the performance of these batch processors.
++ : 254nm UV sterilizers, while not physically removing bacteria, rate. may have bactericidal or bacteriostatic capabilities limited by intensity, contact time, and flow rate