ASTM D6157-97(2017)e1
(Practice)Standard Practice for Determining the Performance of Oil/Water Separators Subjected to a Sudden Release
Standard Practice for Determining the Performance of Oil/Water Separators Subjected to a Sudden Release
SIGNIFICANCE AND USE
5.1 The Clean Water Act promulgated the implementation of water quality standards and contamination limits for a wide range of pollutants including oil and grease. Specifically, the EPA, in 40 CFR Ch. 1, prohibits “the discharges of oil that cause a film or sheen upon or cause discoloration of the surface of the water. . .” Several state and local agencies have adopted this statement in addition to setting concentration limits, that is, 15 mg/L or even 5 mg/L. The purpose of this practice is to evaluate the performance of a separator in regards to the regulations and user requirements when subject to a sudden release. The sudden release may occur in dry weather and local personnel may attempt to hose the contaminated area down or it may occur on a rainy day and enter the separator mixed in with the runoff.
5.2 This practice is not applicable if the influent to a separator is simply runoff from contaminated rainwater. For this case, see Practice D6104.
5.3 This practice is not applicable if the influent to a separator is conveyed by a pumping means.
SCOPE
1.1 This practice describes the testing procedure, any necessary related apparatus, and the sampling technique to be used in determining the performance characteristics of an oil/water separator subjected to the sudden release of a relatively large quantity of hydrocarbons that may appear in its influent in pure form or at high concentration.
1.2 This practice does not address the determination of the performance characteristics of an oil/water separator subjected to surface run-off resulting from rain water draining from improved or unimproved land. In this case, refer to Practice D6104.
1.3 This practice does not address the determination of the performance characteristics of an oil/water separator subjected to a mechanically emulsified influent such as provided by a pump.
1.4 This practice does not investigate the ability of the separator to handle debris or suspended solids, that is, grit or tree leaves.
1.5 While the effluent may meet code requirements for total oil and grease content, this practice does not address the presence of soluble organics, that is, benzene, toluene, ethyl-benzene, and xylene (BTEXs) that may be detected in the effluent. It also does not make any provisions for the effects of detergents, surfactants, soaps or any water soluble matter (that is, salts) or any portion of an essentially insoluble matter that may be found in solution on separation. (Effects of certain water soluble chemicals or solids may be investigated by adding them to the water at predetermined constant concentrations.)
1.6 In order to estimate the effect of water temperature on the performance of the separator, the tests described in this practice must be performed at two water temperatures. The selected temperatures must be at least 10°C (18°F) apart, with the temperature ranging from a minimum of 0°C (32°F) to a maximum of 50°C (122°F).
1.7 This practice does not make any provisions for the variation of pH or temperature during a test run. Refer to Appendix X1 for further detail.
1.8 This practice can be used with a variety of hydrocarbons. It adopts No. 2 fuel oil with a density2 of 845 kg/m3 (52.73 lbm/ft3) and a viscosity2 of 1.9 to 4.1 centistokes at 40°C (104°F) and SAE 90 lubricating oil with a density (See SAE J313) of 930 kg/m3 (58 lbm/ft3) at 15.5°C (60°F) and a viscosity (see SAE J306) of 13.5 to
Note 1: No extrapolation outside the range of the tested influent or effluent oil concentrations is allowed as performance may not be linear. Hence, to establish performance at a higher or lower concentration, the separator shall be tested for that specific condition. In addition, linearity must be established prior to using linear interpolation.
1.9 Since regulations are based on effluent total hydrocarbon content, this practice does not set forth any lower limits on oil particle size for the evaluation of ...
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: D6157 − 97 (Reapproved 2017)
Standard Practice for
Determining the Performance of Oil/Water Separators
Subjected to a Sudden Release
This standard is issued under the fixed designation D6157; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—The Keywords Section was added editorially in December 2017.
1. Scope practice must be performed at two water temperatures. The
selected temperatures must be at least 10°C (18°F) apart, with
1.1 This practice describes the testing procedure, any nec-
the temperature ranging from a minimum of 0°C (32°F) to a
essaryrelatedapparatus,andthesamplingtechniquetobeused
maximum of 50°C (122°F).
in determining the performance characteristics of an oil/water
separator subjected to the sudden release of a relatively large 1.7 This practice does not make any provisions for the
quantity of hydrocarbons that may appear in its influent in pure variation of pH or temperature during a test run. Refer to
form or at high concentration. Appendix X1 for further detail.
1.2 This practice does not address the determination of the 1.8 This practice can be used with a variety of hydrocar-
performance characteristics of an oil/water separator subjected bons. It adopts No. 2 fuel oil with a density of 845 kg/
3 3 2
to surface run-off resulting from rain water draining from m (52.73 lb /ft ) and a viscosity of 1.9 to 4.1 centistokes at
m
improved or unimproved land. In this case, refer to Practice 40°C (104°F) and SAE 90 lubricating oil with a density (See
3 3
D6104. SAE J313) of 930 kg/m (58 lb /ft ) at 15.5°C (60°F) and a
m
viscosity (see SAE J306) of 13.5 to <24 centistokes at 100°C
1.3 This practice does not address the determination of the
(212°F) as the comparative testing media. It is understood that
performance characteristics of an oil/water separator subjected
the results obtained from this practice are only directly
to a mechanically emulsified influent such as provided by a
applicable to No. 2 fuel oil and SAE 90 lubricating oil for the
pump.
tested concentrations and only careful interpolation or
1.4 This practice does not investigate the ability of the
extrapolation, or both, is allowed to other hydrocarbons. Low
separator to handle debris or suspended solids, that is, grit or
viscosity or high density hydrocarbons or hydrocarbons that
tree leaves.
contain a larger fraction of highly soluble compounds may
need to be tested separately.
1.5 While the effluent may meet code requirements for total
oil and grease content, this practice does not address the
NOTE 1—No extrapolation outside the range of the tested influent or
presence of soluble organics, that is, benzene, toluene, ethyl-
effluent oil concentrations is allowed as performance may not be linear.
benzene, and xylene (BTEXs) that may be detected in the
Hence, to establish performance at a higher or lower concentration, the
separator shall be tested for that specific condition. In addition, linearity
effluent. It also does not make any provisions for the effects of
must be established prior to using linear interpolation.
detergents, surfactants, soaps or any water soluble matter (that
1.9 Since regulations are based on effluent total hydrocar-
is, salts) or any portion of an essentially insoluble matter that
may be found in solution on separation. (Effects of certain bon content, this practice does not set forth any lower limits on
oil particle size for the evaluation of separator efficiency.
water soluble chemicals or solids may be investigated by
adding them to the water at predetermined constant concentra- However, a standardized means for mixing oil and water shall
be specified to ensure repeatability. It must be noted however
tions.)
that smaller particles, having a greater surface area to volume
1.6 In order to estimate the effect of water temperature on
ratio, rise at a slower rate than their larger counterparts. (Guide
the performance of the separator, the tests described in this
F933 requires that 20 % of all oil particles be smaller than or
equal to 50 µm and IMO MEPC 60 (30) does not mention any
particle size requirements but asks the user to avoid emulsion
This practice is under the jurisdiction of ASTM Committee D19 on Water and
causing chemicals.)
is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water.
Current edition approved Dec. 15, 2017. Published January 2018. Originally
approved in 1997. Last previous edition approved in 2011 as D6157 – 97 (2011). Bolz, R. E., andTuve, G. L., CRC Handbook of Tables forApplied Engineering
DOI: 10.1520/D6157-97R17E01. Science, 2nd Edition, CRC Press, 1991.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D6157 − 97 (2017)
1.10 Although the tests described in this practice intend to 2.3 SAE Standards:
simulate the performance of a separator subjected to a sudden SAE J306 Axle and Manual Transmission Lubricant Viscos-
ity Classification
release, they do not cover all possible applications. It is the end
SAE J313 Surface Vehicle Recommended Practice — (R)
user’s responsibility to determine whether his separation re-
Diesel Fuels
quirements are within the scope of this practice.
1.11 Aproduct different from the general description herein
3. Terminology
may be tested and found to be in compliance with the
3.1 Definitions:
performance criteria set forth.
3.1.1 For definitions of terms used in this standard, refer to
1.12 The values stated in SI units are to be regarded as Terminology D1129.
standard. The values given in parentheses are mathematical
3.2 Definitions of Terms Specific to This Standard:
conversions to inch-pound units that are provided for informa-
3.2.1 calibration, n—thecertifiedevaluationoftheaccuracy
tion only and are not considered standard.
of a measuring instrument as performed by its manufacturer or
an independent licensed or accredited third party.
1.13 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.2.2 contaminated run-off, n—rain water which has col-
responsibility of the user of this standard to establish appro-
lected oily contaminants from the surfaces it came in contact
priate safety, health, and environmental practices and deter- with and which may appear in the influent to a separator.
Unlikearelease,thelevelofcontaminationinthiscaseismuch
mine the applicability of regulatory limitations prior to use.
lower.
1.14 This international standard was developed in accor-
dance with internationally recognized principles on standard- 3.2.3 effluent, n—the aqueous release from a separator.
ization established in the Decision on Principles for the
3.2.4 flow totalizer, n—a counter, usually attached to a flow
Development of International Standards, Guides and Recom-
meter, that evaluates the total volume of the fluid that has
mendations issued by the World Trade Organization Technical
flowed through over a given time period.
Barriers to Trade (TBT) Committee.
3.2.5 influent, n—the oily aqueous input to a separator.
3.2.6 oily discharge, n—any release of oily contaminants
2. Referenced Documents
into the environment that exceeds the allowable limit.
2.1 ASTM Standards:
3.2.7 re-entrainment, n—the condition in which the level of
D1129 Terminology Relating to Water
contaminationoftheeffluentwaterofaseparatorcontainingoil
D3370 Practices for Sampling Water from Closed Conduits
is higher than the influent contamination level due to internal
D4281 Test Method for Oil and Grease (Fluorocarbon Ex-
remixing. This definition usually applies to situations where
tractable Substances) by Gravimetric Determination
clean water passes through a separator that already contains
(Withdrawn 2012)
Hydrocarbonsstoredwithinandatopthewatersoastoforman
D6104 Practice for Determining the Performance of Oil/
interface.
Water Separators Subjected to Surface Run-Off
3.2.8 release, n—any sudden discharge of an oily substance
F933 Guide for Evaluation of Oil Water Separation Systems
from vessels that are specifically designed to store, contain, or
for Spilled Oil Recovery Applications (Discontinued
transfer oily products such as storage tanks, pipelines, diked
2001) (Withdrawn 2001)
areas, and transfer equipment and which may appear in the
2.2 EPA Standards:
influent to a separator.
EPA-413.1 “Methods for Chemical Analysis of Water and
3.2.9 separator, n—a flow through primary treatment device
Wastes,” EPA 600/4-79-020
the primary purpose of which is to separate oil from water.
EPA-413.2 “Methods for Chemical Analysis of Water and
Wastes,” EPA 600/4-79-020 4. Summary of Practice
EPA-1664 H-Hexane Extractable Material (HEM) and Silica
4.1 The practice evaluates a separator’s ability to inhibit a
Gel Treated N-Hexane Extractable Material (SGT-HEM)
sudden release from escaping into its effluent. For this, a
by Extraction and Gravimetry (Oil and Grease and Total
quantity of hydrocarbon constituting at least the rated oil
Petroleum Hydrocarbons) EPA-821-B-94-004B
storage capacity of the separator is released at the separator’s
40 CFR Ch. 1 (7-1-95 Edition)
rated flow for the test conditions, either in pure form or mixed
with water to form a 500 000-mg/L concentration. It is then
immediately followed with fresh water. The corresponding
effluent hydrocarbon content is determined by obtaining and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
analyzing grab samples.
Standards volume information, refer to the standard’s Document Summary page on
4.2 The data generated in this practice are considered valid
the ASTM website.
The last approved version of this historical standard is referenced on
for the separators tested only. However, the results of these
www.astm.org.
AvailablefromUnitedStatesEnvironmentalProtectionAgency(EPA),William
Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, Available from SAE International (SAE), 400 Commonwealth Dr.,Warrendale,
http://www.epa.gov. PA 15096, http://www.sae.org.
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D6157 − 97 (2017)
tests may be extrapolated to smaller or larger size separators the flow rate, that is, throttling valve and flow meter, orifice
provided that applicable geometric and dynamic similitude are plates, or venturis, to within 5 % of the desired value.
maintained. Where the use of extrapolation is not applicable,
NOTE 2—If the separator is to be fed by gravity, the oil storage tank
that size unit must be subjected to testing.
must be elevated above the water storage tank and the piping sized so as
to help equalize static head. Elevating the oil storage tank 20 % higher
4.3 Other concentrations and quantities of hydrocarbons
than the water storage tank may help equalize hydrostatic head between
may be used. However, this shall be noted in the report and
the oil and water tanks by adjusting for the difference in specific gravity.
when referencing this practice.
6.3 Separator—A separator with an outlet pipe extending
4.4 For the purpose of this test, the water temperature
far enough to allow grab sampling as described in Practices
should be between 50°F and 70°F and the pH of the water
D3370.
between 6 and 9.
6.4 Mixer—A means for mixing the hydrocarbons with the
water consisting of a commercially available horizontal PVC
5. Significance and Use
pipe section with a minimum surface roughness of 0.00015 cm
5.1 The Clean Water Act promulgated the implementation
(0.000005 ft) having a length of at least 20 diameters with one
of water quality standards and contamination limits for a wide
end connected directly to the inlet of the separator. An oil
range of pollutants including oil and grease. Specifically, the
injection port shall be provided at the other end of the pipe and
EPA, in 40 CFR Ch. 1, prohibits “the discharges of oil that
at its bottom portion and shall not extend into the pipe more
causeafilmorsheenuponorcausediscolorationofthesurface
than one third its diameter in order to prevent stratification.
of the water. . .” Several state and local agencies have adopted
The pipe diameter shall be selected such that it runs full and at
thisstatementinadditiontosettingconcentrationlimits,thatis,
a Reynolds number, based on its hydraulic diameter, in excess
15 mg/L or even 5 mg/L. The purpose of this practice is to
of 70 000 and a velocity in excess of 1 m/s (3.28 ft/s) with
evaluate the performance of a separator in regards to the
water being the liquid medium. The injection port diameter
regulations and user requirements when subject to a sudden
shall be sized to be capable of providing the hydrocarbons into
release.The sudden release may occur in dry weather and local
the pipe, at the higher test concentration, an injection velocity
personnel may attempt to hose the contaminated area down or
approximately in excess of 1 m/s.
it may occur on a rainy day and enter the separator mixed in
6.5 Influent Sampling Port—An influent sampling port for
with the runoff.
temperature and pH reading. (If on-line temperature and pH
5.2 This practice is not applicable if the influent to a
readers are not available, a small sample should be extracted
separator is simply runoff from contaminated rainwater. For
andthetemperaturereadimmediatelyatthebeginningofevery
this case, see Practice D6104.
test. pH analysis may be performed at a later time.)
5.3 This practice is not applicable if the influent to a
7. Procedure
separator is conveyed by a pumping means.
7.1 Theseparatorshallbetestedatitsratedflowandstorage
capacities for the sudden release test conditions.
6. Test Set-Up and Apparatus
7.2 The Sudden Release:
6.1 Water Supply—The water supply can be either a water
7.2.1 Pure Hydrocarbon Release—The volume of the pure
main,awaterreservoirandapump,oranelevatedstoragetank
hydrocarbonshallbeatleastequaltotheratedstoragecapacity
capable of providing the volume and flow rate of water
of the separator and shall be released at the rated flow followed
necessary for a test run as described in the procedure. If either
immediately by three volume changes of clean water.
a storage tank or reservoir is used, it is suggested that the
7.2.2 500 000 mg/L Release—The 500 000 mg/L of hydro-
volume be at least three times the liquid vol
...
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