ASTM D6161-98
(Terminology)Standard Terminology Used for Crossflow Microfiltration, Ultrafiltration, Nanofiltration, and Reverse Osmosis Membrane Processes
Standard Terminology Used for Crossflow Microfiltration, Ultrafiltration, Nanofiltration, and Reverse Osmosis Membrane Processes
SCOPE
1.1 This terminology covers the use of crossflow microfiltration, ultrafiltration, nanofiltration and reverse osmosis for membrane separation processes.
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An American National Standard
Designation: D 6161 – 98
Standard Terminology
Used for Crossflow Microfiltration, Ultrafiltration,
Nanofiltration and Reverse Osmosis Membrane Processes
This standard is issued under the fixed designation D6161; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope the assumed or accepted true value, and includes both
precision and bias.
1.1 This terminology covers the use of crossflow microfil-
acetylation—substitution of an acetyl radical for an active
tration, ultrafiltration, nanofiltration and reverse osmosis for
hydrogen. Specifically, formation of cellulose acetate from
membrane separation processes.
cellulose.
2. Referenced Documents acidity—the quantitative capacity of aqueous media to react
with hydroxyl ions.
2.1 ASTM Standards:
activated carbon—granulated or powdered activated carbon
D1129 Terminology Relating to Water
usedtoremovetastes,odor,chlorine,chloramines,andsome
D2035 Practice for Coagulation-Flocculation Jar Test of
organics from water. A family of carbonaceous substances
Water
manufactured by processes that develop adsorptive proper-
3. Significance and Use
ties.
adsorption—the holding of a substance onto the surface of a
3.1 The need to understand the relationships found in
solid by chemical surface forces, without forming new
membraneunitprocessesforwatertreatmentincreaseswiththe
chemical bonds.
continuing demand for these separation systems. Defining the
aerobic bacteria—bacteria that require oxygen for growth.
terms common to crossflow microfiltration, ultrafiltration,
See bacteria, aerobes.
nanofiltration and reverse osmosis processes assist the manu-
aggregate—granular material such as sand, gravel, crushed
facturer, consultant and end-user in eliminating inter-process
stone.
terminology confusion.
air scour—distributing air over the entire filter area at the
4. Terminology
bottom of a filter media flowing upward to improve the
effectiveness of backwashing or to permit the use of lower
4.1 Definitions:
backwash water flow rate, or both.
absorption—the holding of a substance within a solid by
algae—any of a group of chiefly aquatic mono cellular plants
cohesive or capillary forces.
with chlorophyll often masked by a brown or red pigment.
accumulator—a pulsation dampener installed on the suction
alkalinity—thequantitativecapacityofaqueousmediatoreact
and/or discharge lines of pumps, generally plunger type, to
with hydrogen ions. “M” alkalinity is that which will react
minimize pressure surges and provide uniformity of flow.
with acid as the pH of the sample is reduced to the
accuracy—the closeness of agreement between an observed
methylorange endpoint of about 4.5. “P” alkalinity is that
value and an accepted reference value. Where an accepted
which reacts with acid as the pH of the sample is reduced to
reference value is not available, a measure of the degree of
the phenolphthalein end point of 8.3.“ M” is the total
conformity of a value generated by a specific procedure to
alkalinity which is the sum of hydroxide plus carbonate plus
bicarbonate contents, “P” includes all the hydroxyl and half
the carbonate content.
alum—aluminum sulfate, AL (SO ) XH O (X = 14-18), a
2 4 3 2
This terminology is under the jurisdiction ofASTM Committee D-19 onWater
coagulant.
and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion
Exchange Materials.
ambient temperature—the temperature of the surroundings,
CurrenteditionapprovedMarch10,1998.PublishedDecember1998.Originally
typically 20°– 25°C.
published as D 6161 – 97. Last previous edition D 6161–97.
2 amorphous—non crystalline, devoid of regular cohesive
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 11.02. structure.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959, United States.
D6161–98
anaerobicbacteria—bacteria that do not use oxygen. Oxygen dispersed in soil, water, organic matter, and the bodies of
is toxic to them. See bacteria, anaerobes. plants and animals. Either autotrophic (self-sustaining, self-
amphoteric—capable of acting as an acid or a base. generative), saprophytic (derives nutrition from non-living
−10 −4
angstrom (A)—a unit of length equaling 10 metres, 10 µ organic material already present in the environment), or
−8 −9
metres, 10 centimetres and 3.937 3 10 in. The symbol parasitic (deriving nutrition from another living organism).
is Å, A or A.U. . Often symbiotic (advantageous) in man, but sometimes
anion—negatively charged ion. pathogenic.
anion exchange material—a material capable of the revers- bactericide—agent capable of killing bacteria.
ible exchange of negatively charged ions. bacteriostat—substance that prevents bacterial growth and
anisotropic membrane—a nonuniform structure in cross- metabolism but does not necessarily kill them.
section; typically the support substructure has pores much bank—a grouping of devices. See array, block, train.
2 2
larger than the barrier layer. See asymmetric membranes. bar—unitofpressure;14.50lbs/in. ,1.020kg/cm ,0.987atm,
anode—positive electrode. 0.1 MPa.
anionic polyelectrolyte—usually acrylamide and acrylamide BAT—best available technology.
•
and acrylic copolymers, negatively charged, used for baume scale,Be—a measure of the density of a solution
coagulation/flocculation, see Polyelectrolytes. relative to water.
anthracite—a granular hard coal used as a filtration media,
•
BE 5145 2
commonly used as the coarser layer in dual and multimedia
specificgravity*
filters.
United States for densities greater than unity.
antifoulant—see antiscalant.
antiscalant—a compound added to a water which inhibits the •
BE 5 2130
specificgravity*
precipitation of sparingly soluble inorganic salts.
anti-telescoping device—a plastic or metal device attached to For densities less than unity.
the ends of a spiral wound cartridge to prevent movement of *60°F/60°F
the cartridge leaves in the feed flow direction, due to high bed depth—the depth of the filter medium or ion exchange
feed flows. resin in a vessel.
AOC—assimilable organic carbon. bed expansion—the depth increase of filter medium or ion
aquifer—a water-bearing geological formation that provides a exchange resin that occurs during backwashing.
ground water reservoir. binders—in reference to cartridge filters, chemicals used to
aramid—a fully aromatic polyamide. hold, or 8bind’, short fibers together in a filter.
array—anarrangementofdevicesconnectedtocommonfeed, biocide—a substance that kills all living organisms.
product and reject headers; that is, a 2:1 array. biologicaldeposits—thedebrisleftbyorganismsasaresultof
asymmetric membrane—membrane which has a change in their life processes.
pore structure with depth. See anisotropic membranes. biomass—any material which is or was a living organism or
ATD—see anti-telescoping device.
excreted from a micro-organism.
atomicweight—the relative mass of an atom based on a scale biostat—a substance that inhibits biological growth.
in which a specific carbon atom (carbon 12) is assigned a
binding—in surface filtration, a build-up of particulates on the
mass value of 12. filter, restricting fluid flow through the filter at normal
ATP—adenosine triphosphate. pressures.
autopsy—the dissection of a membrane module or element to block—a grouping of devices in a single unit having common
investigate causes of unsatisfactory performance. control. See array, bank, train.
availability—theon-streamtimeorratedoperatingcapacityof BOD (biochemical oxygen demand)—the amount of dis-
a water treatment system. solved oxygen utilized by natural agencies in water in
a-value—membrane water permeability coefficient. The coef- stabilizing organic matter at specified test conditions.
ficient is defined as the amount of water produced per unit body feed—the continuous addition of filter medium (for
area of membrane when net driving pressure (NDP) is unity, example, diatomaceous earth) to sustain the efficacy of the
3 2
a unit of measurement is m /hr/m /kPa. filter.
AWWA—American Water Works Association. BOO—build, own, operate.
AWWARF—American Water Works Association Research BOOT—build, own, operate and transfer.
Foundation. boundary layer—a thin layer at the membrane surface where
backwash—reverse the flow of water with/without air either water velocities deviate significantly less than those in the
across or through a medium or membrane designed to bulk flow.
remove the collected foreign material from the bed or brackish water—water with an approximate concentration of
membranes.
totaldissolvedsolidsrangingfrom1000to10000mg/L.See
bacteria—any of a class of microscopic single-celled organ- high brackish water, sea water.
isms reproducing by fission or by spores. Characterized by
breakpoint chlorination—the point at which the water chlo-
round, rod-like spiral or filamentous bodies, often aggre- rine demand is satisfied and any further chlorine is the
gated into colonies or mobile by means of flagella. Widely chlorine residual, the “free” chlorine species.
D6161–98
breaktank—a storage device used for hydraulic isolation and cathode—negative electrode.
surge protection. cation—positively charged ion.
brine—the concentrate (reject) stream from a crossflow mem- cation exchange material—a material capable of the revers-
brane device performing desalination. Portion of the feed ible exchange of positively charged ions.
stream which does not pass through the membrane. cationic polyelectrolyte—a polymer containing positively
brine(concentrate)seal—a rubber lip seal on the outside of a charged groups used for coagulation/flocculation, usually
spiral wound cartridge which prevents feed by-pass between dimethyl - aminoethyl methacrylate or dimethyl-aminoethyl
the cartridge and the inside pressure vessel wall. acrylate. See polyelectrolyte.
brine seal carrier—see ATD. cellulose—an amorphous carbohydrate (C H O ) that is the
6 10 5
brine system staging—a process in which the concentrate, principal constituent of wood and plants.
under pressure, of a group of membrane devices is fed cellulose acetate (CA)—in the broad sense, any of several
directly to another set of membrane devices to improve the esters of cellulose and acetic acid.
efficiency of the water separation. celsius (°C)—the designation of the degree on the Interna-
bubble point pressure—the pressure necessary to displace a tional Practical Temperature Scale. Formerly called centi-
liquid held by surface tension forces from the largest grade,°C=K minus 273.15. K = Kelvin.
equivalent capillaries in a membrane filter. centigrade—since 1948, now called Celsius, a temperature
bubblepointtest—a nondestructive membrane filter test used scale.
to assess filter integrity and proper installation. ceramic membrane—generally a glass, silica, alumina, or
bundle—ageneraltermforacollectionofparallelfilamentsor carbon based membrane. Generally used in micro and
fibres. ultrafiltration.They tend to withstand high temperatures and
B-value—salt diffusion coefficient— The coefficient is de- widepHrangesandbemorechemicallyinertthanpolymeric
fined as the amount of salt transferred per unit area of membranes.
membrane when the difference in salt concentration across CFU—colony forming unit; unit used in the measure of total
the membrane is unity. A unit of measurement is m/h. bacteria count (TBC).
BWRO—brackish water reverse osmosis. channeling—unequal flow distribution in the desalination
CAC—combined available chlorine. bundle or filter bed.
calciumcarbonateequivalents(mg/LasCaCO )—amethod chelatingagents—asequesteringorcomplexingagentthat,in
for expressing mg/L as ion in terms of calcium carbonate. aqueous solution, renders a metallic ion inactive through the
Concentrationincalciumcarbonateequivalentsiscalculated formation of an inner ring structure with the ion.
by multiplying concentration in mg/L of the ion by the chemical feed pump—a pump used to meter chemicals, such
equivalentweightofcalciumcarbonate(50)anddividingby as chlorine of polyphosphate, into a feed water supply.
the equivalent weight of the ion. (See Table 1). chloramine—acombinationofchlorineandammoniainwater
carbonate hardness—the hardness in a water caused by which has bactericidal qualities for a longer time than does
carbonatesandbicarbonatesofcalciumandmagnesium.The free chlorine.
amount of hardness equivalent to the alkalinity formed and chlorine—chemical used for its qualities as a bleaching or
deposited when water is boiled. In boilers, carbonate hard- oxidizing agent and disinfectant in water purification.
ness is readily removed by blowdown. chlorinedemand—theamountofchlorineusedupbyreacting
calcium hypochlorite—Ca (HCIO) , a disinfection agent. with oxidizable substances in water before chlorine residual
cartridge—see spiral-wound cartridge. can be measured.
catalyst—a substance whose presence initiates or changes the chlorine, residual—the amount of available chlorine present
rate of a chemical reaction, but does not itself enter into the in water at any specified time.
reaction. chlorine,freeavailable—thechlorine(Cl ),hypochloriteions
A,B
TABLE 1 Conversion Factors
mg/l mg/l Clark or Grain per French German EPM Atomic
as Ion as CaCO English Degree US Gallon Degree Degree MEQ/L Weight
Ca++ 2.495 0.175 0.0583 0.250 0.140 0.0499 40.08
Mg++ 4.112 0.288 0.0583 0.411 0.231 0.0823 24.32
Na+ 2.175 0.152 0.0583 0.218 0.122 0.0435 22.99
K+ 1.279 0.089 0.0583 0.128 0.072 0.0256 39.10
Sr++ 1.141 0.080 0.0583 0.114 0.064 0.0288 87.63
Ba++ 0.728 0.051 0.0583 0.073 0.041 0.0146 137.36
Fe++ 1.791 0.125 0.0583 0.179 0.101 0.0358 55.85
–
HCO3 0.819 0.057 0.0583 0.082 0.046 0.0164 61.02
SO 1.041 0.073 0.0583 0.104 0.058 0.0208 96.07
4–
–
Cl 1.410 0.098 0.0583 0.141 0.079 0.0282 35.46
–
F 2.632 0.184 0.0583 0.263 0.148 0.0526 19.00
–
NO 0.806 0.056 0.0583 0.081 0.045 0.0161 62.00
––
CO 1.666 0.117 0.0583 0.167 0.094 0.0323 60.01
–––
PO 1.579 0.110 0.0583 0.158 0.089 0.0316 94.98
A
To convert from mg/l as ion to any other unit multiply by factor.
B
To convert to mg/l as ion from any other unit divide by factor.
D6161–98
–
C ~brinewater concentration!
(OCl ), hypochlorous acid (HOCl) or the combination
B
CF 5
C ~feedwater concentration!
thereof present in water. F
chlorine, total available—the sum of free available chlorine
plus chloramines present in water.
5 ~approximation!
1 2conversion
CIP—cleaning-in-place.
concentration polarization—the increase of the
...
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