1、Designation: D6538 10 D6538 12Standard Guide forSampling Wastewater With Automatic Samplers1This standard is issued under the fixed designation D6538; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the selection and use of automatic wastewater samplers including procedures for their use in obtainingrepresentative sam
3、ples. Automatic wastewater samplers are intended for the unattended collection of samples that arerepresentative of the parameters of interest in the wastewater body. While this guide primarily addresses the sampling ofwastewater, the same automatic samplers may be used to sample process streams and
4、 natural water bodies.1.2 The guide does not address general guidelines for planning waste sampling activities (see Guide D4687), development ofdata quality objectives (see Practice D5792), the design of monitoring systems and determination of the number of samples tocollect (see Practice D6311), op
5、erational details of any specific type of sampler, in-situ measurement of parameters of interest, dataassessment and statistical interpretation of resultant data (see Guide D6233), or sampling and field quality assurance (see GuideD5612). It also does not address sampling groundwater.1.3 The values
6、stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3.1 ExceptionThe inch-pound units given in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use.
7、It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD3694 Practices for Preparation of Sample Cont
8、ainers and for Preservation of Organic ConstituentsD3856 Guide for Management Systems in Laboratories Engaged in Analysis of WaterD4687 Guide for General Planning of Waste SamplingD4840 Guide for Sample Chain-of-Custody ProceduresD5088 Practice for Decontamination of Field Equipment Used at Waste Si
9、tesD5283 Practice for Generation of Environmental Data Related to Waste Management Activities: Quality Assurance and QualityControl Planning and ImplementationD5612 Guide for Quality Planning and Field Implementation of a Water Quality Measurement ProgramD5681 Terminology for Waste and Waste Managem
10、entD5792 Practice for Generation of Environmental Data Related to Waste Management Activities: Development of Data QualityObjectivesD5851 Guide for Planning and Implementing a Water Monitoring ProgramD5956 Guide for Sampling Strategies for Heterogeneous WastesD6233 Guide for Data Assessment for Envi
11、ronmental Waste Management ActivitiesD6311 Guide for Generation of Environmental Data Related to Waste Management Activities: Selection and Optimization ofSampling DesignE856 Definitions of Terms and Abbreviations Relating to Physical and Chemical Characteristics of Refuse Derived Fuel(Withdrawn 201
12、1)31 This guide is under the jurisdiction of ASTM Committee D34 on Waste Management and is the direct responsibility of Subcommittee D34.01.03 on Sampling Equipment.Current edition approved Dec. 1, 2010Sept. 1, 2012. Published January 2011December 2012. Originally approved in 2000. Last previous edi
13、tion approved in 20052010as D6538 00D6538(2005).-10. DOI: 10.1520/D6538-10.10.1520/D6538-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document
14、 Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recom
15、mends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology
16、3.1 DefinitionsFor definitions of terms used in this guide, refer to Terminology D5681.4. Significance and Use4.1 This guide provides persons responsible for designing and implementing wastewater sampling programs with a summaryof the types of automatic wastewater samplers, discusses the advantages
17、and disadvantages of the different types of samplers andaddresses recommended procedures for their use. The field settings are primarily, but not limited to, open channel flows in enclosed(e.g., sewer) systems or open (e.g., streams or open ditches, and sampling pressure lines) systems.5. Automatic
18、Versus Manual Sampling (1, 2)35.1 The advantages and disadvantages of manual and automatic sampling are summarized in Table 1. The decision as to whetherto use manual or automatic sampling involves many considerations in addition to equipment costs. In general, manual samplingis indicated when infre
19、quent samples are required from a site, when biological or sediment samples, or both, are also required,when investigating special incidents, where sites will not allow the use of automatic devices, for most bacteriological sampling,where concentrations remain relatively constant, etc. The use of au
20、tomatic samplers is indicated where frequent sampling isrequired at a given site, where long-term compositing is desired, where simultaneous sampling at many sites is necessary, etc.Automatic sampling is often the method of choice for storm-generated discharge studies, for longer outfall monitoring,
21、 fortreatment plant efficiency studies, where 24-h composite samples are required, etc. The user should review 7.1.23 before selectingmanual or automatic sampling.6. Types of Samples Collected by Automatic Samplers6.1 Grab SamplesAs defined under the U.S. Environmental Protection Agencys (EPA) Natio
22、nal Pollutant DischargeElimination Program, grab samples are individual samples collected over a period of time not exceeding 15 min and arerepresentative of conditions at the time of sampling (4). Grab samples are sometimes also called individual or discrete samples (5).Sequential grab samples are
23、a series of grab samples collected at constant increments of either time or flow and provide a historyof variation. Grab samples are appropriate when samples are needed to:6.1.1 Characterize an effluent that is not continuous,6.1.2 Provide information about instantaneous concentrations of pollutants
24、,6.1.3 Allow collection of samples of varied volume,6.1.4 Corroborate composite samples,3 The last approved version of this historical standard is referenced on www.astm.org.3 The boldface numbers given in parentheses refer to a list of references at the end of the standard.TABLE 1 Advantages and Di
25、sadvantages of Manual versusAutomatic Sampling of Wastewater (3)Type Advantages DisadvantagesManual Low capital cost Increased variability due tosample handlingPersonnel can compensate forvarious situationsInconsistency in collectionPersonnel can documentunusual conditionsHigh cost of labor assuming
26、composite or multiple grabsamples are collectedNo maintenance Repetitious and monotonoustask for personnelLow maintenance Repetitious and monotonoustask for personnelExtra samples can be collectedin a short time if necessaryAutomatic Consistent samples Considerable maintenance forbatteries and clean
27、ing;susceptible to plugging bysolidsDecreased variability caused bysample handlingRestricted in size to the generalspecificationsMinimal labor requirement forsamplingGreater potential for samplecontaminationCapable of collecting multiplegrab and multiple aliquotcomposite samplesMay be subject to dam
28、age byvandalsHigh capital costD6538 1226.1.5 Monitor parameters not amenable to compositing (for example, pH, temperature, dissolved oxygen, chlorine, purgeableorganics (unless a specialized sampler is used), oil and grease and others specified by a permit which may include phenols, sulfitesand hexa
29、valent chromium).6.1.6 Characterize a waste stream in detail where rapid fluctuations of parameters occur (sequential grabs).6.2 Composite SamplesComposite samples are collected over time, either by continuous sampling or by mixing discretesamples, and represent the average characteristics of the wa
30、ste stream during the compositing period. Composite samples arecollected when stipulated in a permit, when average pollutant concentration during the compositing period is to be determined, andwhen wastewater characteristics are highly variable. There are four types of composite samples.6.2.1 Time C
31、omposite SamplesThis method requires discrete sample aliquots be collected in one container at constant timeintervals. The method is appropriate when the flow of the stream is constant (flow rate does not vary more than 610 % of theaverage flow rate (4) or when flow monitoring equipment is not avail
32、able. The EPA allows time-proportional sampling andrequires samples be collected every 15-min, on average, over a 24-h period.6.2.2 Flow-Proportional Composite SamplesThere are two methods used for this type of sample (4). The most commonlyused method with automatic samplers collects a constant samp
33、le volume at varying time intervals proportional to stream flow basedon input from a flow monitor (for example, a 200-mL aliquot is collected for every 5000 L of flow). In the other flow-proportionalcompositing method, the sample is collected by varying the volume of each aliquot as the flow varies,
34、 while maintaining a constanttime interval between the aliquots.6.2.3 Sequential Composite SamplesA sequential composite sample is composed of a series of short-period composites, eachof which is held in an individual container, for example, four sample aliquots are composited (one every 15 min) to
35、form hourlycomposites (4). The 24-h sequential composite is then manually made by compositing the individual 1-h composite sample.6.2.4 Continuous Composite SamplesThis method requires that the sample be collected continuously at a constant rate orproportional to flow (4). This method is seldom used
36、 with automatic samplers.7. Attributes of Automatic Samplers7.1 The EPA (6) developed a list of attributes of the ideal automatic sampler for their use and EPA Region 4 (7) and others (3)have noted other important attributes. These attributes and requirements may be specific to EPAs use and were pri
37、marily directedat suction lift type automatic samplers. Not all these sampler characteristics will be important to all users but their considerationmay guide persons selecting automatic samplers. The desirable features of automatic samplers listed below have been summarizedand combined from the refe
38、renced documents.7.1.1 Capable of AC/DC operation with adequate dry battery energy storage for 120-h operation at 1-h sampling intervals.7.1.2 Suitable for suspension in a standard manhole yet still accessible for inspection and sample removal. A secure harness ormounting device if the sampler is pl
39、aced in a sewer.7.1.3 Total weight, including batteries, less than 18 kg. Compact and portable enough for one-person installation.7.1.4 Sample collection interval adjustable from 10 min to 4 h.7.1.5 Capable of collecting a single 9.5-L (2.5-gal) sample and/or collecting 500-mL (0.13-gal) discrete sa
40、mples in a minimumof 24 containers. The individual sample aliquot must be at least 100 mL.7.1.6 Capable of multiplexing repeated aliquots into discrete bottles.7.1.7 One intake hose with a minimum inner diameter of 0.64 cm (0.25 in) and a weighted, streamlined intake screen whichwill prevent accumul
41、ation of solids.7.1.8 Intake hose liquid velocity adjustable from 0.6 to 3 m/s (2.0 to 10 ft/s) with dial setting.7.1.9 Minimum lift capacity of 6.1 m (20 ft).7.1.10 Explosion proof construction.7.1.11 Watertight exterior case to protect components in the event of rain or submersion.7.1.12 Exterior
42、case capable of being locked, including lugs for attaching steel cable to prevent tampering and to providesecurity.7.1.13 An integral sample container compartment capable of maintaining samples at 4 to 6C for a period of 24 h at ambienttemperatures up to 38C.7.1.14 Capable of operating in a temperat
43、ure range from 10 to 40C with the exception of the intake hose.7.1.15 A purge cycle to flush the sample intake tubing before and after each collection interval, and a mechanism to sense andclear a plugged sample line and then collect the complete sample. Samplers may be programmed to perform an air
44、purge beforeand after sampling, and a liquid rinse before and after a sample is drawn.7.1.16 Capable of collecting flow-proportional and time-composite samples.7.1.17 Materials of construction that contact the sample must not compromise the integrity of the sample for the intended use.NOTE 1Some ref
45、erences prohibited sample contact with metal (6) and contact with plastic or metal parts when parameters to be analyzed could beimpacted by these materials (7).7.1.18 Water velocity in intake hose (greater than 0.6 m/s 2.0 ft/s) and aliquot volume are independent of lift heightsexperienced during th
46、e sampling event.7.1.19 Overall construction, including casing, of materials resistant to corrosion (plastics, fiberglass, stainless steel).D6538 1237.1.20 Exterior surface a light color to reflect sunlight.7.1.21 Low cost, availability of spare parts, warranty, ease of maintenance, reliability and
47、ruggedness of construction, andcapable of being repaired in the field.7.1.22 Computer Communication:7.1.22.1 Create exportable output files of program settings, sampling program, and history of times, volumes, and other programexecution information.7.1.22.2 Ability to calibrate the sample pump volum
48、e, and calibrate any attached parameter modules.7.1.23 Other FactorsOther factors (3) that should be considered in selecting an automatic sampler are the:7.1.23.1 Expected variation in water or wastewater composition with time,7.1.23.2 Variation of flow rate with time,7.1.23.3 Specific gravity of th
49、e liquid7.1.23.4 Concentration and density of suspended solids of interest,7.1.23.5 Presence of floating materials,7.1.23.6 Characteristics of the site where the sampler will be placed (e.g., spaced needed for the sampler placement),7.1.23.7 Range of intended use (a permanent site or traveling sampler),7.1.23.8 Skill level required for installation and operation of the sampler, and7.1.23.9 The level of accuracy desired.8. Types of Automatic Samplers (1,2,3)8.1 There are three main types of automatic samplers, suction lift, pressure or forced flow, and mechanic
