1、Designation: D7243 11Standard Guide forMeasuring the Saturated Hydraulic Conductivity of PaperIndustry Sludges1This standard is issued under the fixed designation D7243; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 Paper industry sludges are industrial by-products de-rived from wastewater treatment operations at plants associatedwit
3、h the manufacturing of paper. These sludges typicallyconsist of clay and organic matter. They may also contain lowlevels of inorganic and organic contaminants and can be rich inmicrobes. Traditionally, paper industry sludges have beendisposed in municipal solid waste landfills or solid wastemonofill
4、s. However, in the interest of sustainability, applica-tions are being developed where sludges can be used benefi-cially. One application is using sludge to construct hydraulicbarriers (for example, for use in a landfill cap). Such applica-tions generally require that the hydraulic conductivity of t
5、hesludge be measured.1.2 Compacted paper industry sludges generally behave likesoils and are amenable to geotechnical testing methods. How-ever, several of their attributes require special attention duringtesting. Compacted industry sludges generally are highlycompressible due to their organic compo
6、nent. Thus, theirhydraulic conductivity can be more sensitive to the effectivestress and hydraulic gradient applied during testing than mostsoils. The microbes in paper sludge can also produce gasduring testing, confounding testing methods.1.3 This guide is intended to supplement ASTM D5084,Test Met
7、hods for Measurement of Hydraulic Conductivity ofSaturated Porous Materials Using a Flexible Wall Permeame-ter. The purpose of the guide is to provide additional guidanceon issues relevant to testing sludges using Test MethodsD5084. The guide applies to specimens compacted in thelaboratory using pro
8、cedures such as those described in TestMethods D698 and D1557 or undisturbed specimens collectedfrom the field using procedures such as Practice D1587 orPractice D7015.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This
9、 standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. This standardcontains
10、a hazards section regarding the use of biocides(Section 10).1.6 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action. This document cannot replace education orexperience and should be used in conjunction with professionaljud
11、gment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intended to repre-sent or replace the standard of care by which the adequacy ofa given professional service must be judged, nor should thisdocument be applied without consideration of a projects man
12、yunique aspects. The word “Standard” in the title of thisdocument means only that the document has been approvedthrough the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD698 Test Methods for Laboratory Compaction Charac
13、ter-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D1557 Test Methods for Laboratory Compaction Charac-teristics of Soil Using Modified Effort (56,000 ft-lbf/ft3(2,700 kN-m/m3)D1587 Practice for Thin-Walled Tube Sampling of Soils forGeotechnical PurposesD2216 Test Methods for Lab
14、oratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and Construction1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Roc
15、kand is the direct responsibility of Subcommittee D18.04 on Hydrologic Propertiesand Hydraulic Barriers.Current edition approved Nov. 1, 2011. Published December 2011. Originallyapproved in 2006. Last previous edition approved in 2006 as D724306a. DOI:10.1520/D7243-11.2For referenced ASTM standards,
16、 visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 194
17、28-2959, United States.D5084 Test Methods for Measurement of Hydraulic Con-ductivity of Saturated Porous Materials Using a FlexibleWall PermeameterD7015 Practices for Obtaining Intact Block (Cubical andCylindrical) Samples of SoilsD7100 Test Method for Hydraulic Conductivity Compat-ibility Testing o
18、f Soils with Aqueous Solutions3. Terminology3.1 DefinitionsFor common definitions of other terms inthis standard, see Terminology D653.3.1.1 paper industry sludgeporous solid material derivedfrom clarification of water during wastewater treatment opera-tions at plants producing paper and similar mat
19、erials. Alsoreferred to as paper sludge, papermill sludge, fiber clay, paperclay, or sludge.3.1.2 head loss, hLor hthe change in total head of wateracross a given distance.3.1.2.1 DiscussionTypically the change in total head isacross the influent and effluent lines connected to the per-meameter, whi
20、le the given distance is typically the length ofthe test specimen.3.1.3 permeameterthe apparatus (cell) containing the testspecimen in a hydraulic conductivity test.3.1.3.1 DiscussionThe apparatus in this case is typically atriaxial-type cell with all of its components (top and bottomspecimen caps,
21、stones, and filter paper; membrane; chamber;top and bottom plates; valves; etc.). However, the cell gener-ally does not have a loading piston.3.1.4 hydraulic conductivity, kthe rate of discharge ofwater under laminar flow conditions through a unit cross-sectional area of porous medium under a unit h
22、ydraulicgradient and standard temperature conditions (20C).3.1.4.1 DiscussionThe term coeffcient of permeability (orpermeability) is often used instead of hydraulic conductivity,but hydraulic conductivity is used exclusively in this standard.These terms are synonymous.4. Significance and Use4.1 This
23、 guide is intended to supplement the methods andprocedures described in Test Methods D5084. When followingthe recommendations in this guide to test paper sludges, allassumptions and limitations described in Test Methods D5084apply.4.2 This guide only applies to hydraulic conductivity testson paper i
24、ndustry sludges where one-dimensional laminar flowof water is imposed using a flexible-wall permeameter.4.3 The hydraulic conductivity of sludges, and other porousmaterials, generally decreases as the degree of water saturationdecreases. This guide applies only to water-saturated sludgecontaining ne
25、gligible amounts of gas.4.4 This guide applies only to permeation of paper industrysludges with water. Information on testing porous materialswith liquids other than water can be found in Test MethodD7100.4.5 The hydraulic conductivity of paper sludge measured inthe laboratory following Test Methods
26、 D5084 and the recom-mendations in this guide may or may not be comparable to thehydraulic conductivity of in-place sludge. The issue has notbeen fully investigated. Therefore, the results should be appliedto field situations with caution and by qualified personnel.NOTE 1The quality of the result pr
27、oduced when using the recommen-dations in this guide depends on the competence of the personnelperforming the testing and the suitability of the equipment and facilitiesthat are employed. Agencies that meet the criteria of Practice D3740 aregenerally considered capable of competent and objective tes
28、ting, sam-pling, inspection, etc. Users of this guide are cautioned that compliancewith Practice D3740 does not in itself ensure reliable results. Reliableresults depend on many factors; Practice D3740 provides a means ofevaluating some of those factors.5. Reagents5.1 Permeant Water:5.1.1 Selection
29、of the permeant water should follow theinstructions in Section 6 of Test Methods D5084. Comparativetesting has been conducted to assess whether the hydraulicconductivity of sludge is sensitive to the type of water used fortesting. Tests conducted by Nelson and Benson3indicate thatessentially the sam
30、e hydraulic conductivity is obtained ifhydraulic conductivity tests on paper sludge are conductedwith tap water, deionized water, 0.005 M CaCl2, 0.01 M CaCl2,or 0.01 M CaSO4. These permeant waters should be consideredequivalent when testing paper sludge.5.1.2 In some cases, a biocide may be added to
31、 the permeantwater to prevent generation of gases associated with microbialactivity. Testing conducted previously3suggests that biocidesdo not alter the hydraulic conductivity of paper sludges whenused at concentrations recommended by the manufacturer.However, comprehensive testing has not been cond
32、ucted toassess how all biocides affect the hydraulic conductivity ofpaper sludges (for example, through chemical interactions withthe solid phase). If chemical interactions are a concern, anassessment can be made with side-by-side testing using analternative method to prevent gas generation.6. Proce
33、dures to Minimize Gas Generation6.1 Gases generated by microbial activity can confoundhydraulic conductivity testing of paper sludges. Indications ofgas generation include: (1) inability to meet the terminationcriteria in Test Methods D5084 for steady hydraulic conduc-tivity and continuity (section
34、9.5 in Test Methods D5084), (2)flow in the influent system in the opposite direction of theapplied hydraulic gradient, and (3) outflow much greater thaninflow. This section describes how to deal with gas generation.6.2 Gas generation can be minimized or eliminated bypreventing or minimizing microbia
35、l activity or by applyingelevated backpressure.6.2.1 Microbial activity can be minimized by temperaturecontrol or through the use of biocides.6.2.1.1 Temperature control consists of placing the per-meameter containing the test specimen in a chamber where thetemperature is greater than 0C and no more
36、 than 4C. Akitchen refrigerator works well for this purpose. The tempera-ture of the chamber should be controlled to within 61C and3Nelson, M., and Benson, C., “Laboratory Hydraulic Conductivity TestingProtocols for Paper Sludges Used for Hydraulic Barriers,” Technical Bulletin No.848, National Coun
37、cil for Air and Stream Improvement, Research Triangle Park,NC, 2002.D7243 112must be maintained above 0C at all times. At lower tempera-tures, the effects of temperature on the viscosity and density ofwater reduce the hydraulic conductivity. Thus, when tempera-ture is used to control microbial activ
38、ity, the hydraulic conduc-tivity must be adjusted to standard conditions (20C) using themethod described in section 10.3 of Test Methods D5084.Temperature control is the preferred method for minimizinggas generation.6.2.1.2 Biocides that can be dissolved in water can be usedto control gas generation
39、. DOWICIL (2,2-dibromo-3-nitrilopropionamide) has been found effective at preventing gasgeneration when mixed with the permeant water at concentra-tions between 10002000 ppm.3When used at these concen-trations, testing has also shown that the hydraulic conductivityis comparable to that obtained when
40、 testing with tap wateralone under cool conditions that limit microbial activity (asdescribed in section 6.2.1.1). When using biocides, care shouldbe used to ensure that the biocide is well mixed with thepermeant water following instructions provided by the manu-facturer.6.2.2 Gas generated by micro
41、bial activity can be suppressedusing elevated backpressure. The backpressure required tosuppress gas generation can be determined by incrementallyincreasing the backpressure as described in section 9.3 of TestMethods D5084 followed by observation of the inflow andoutflow for two or more days. The ba
42、ckpressure is sufficientwhen the adverse affects caused by gas generation (describedin section 6.1) are no longer present. In most cases, thebackpressure will need to exceed 330 kPa to be effective inminimizing gas generation.7. Selection of Effective Stress and Hydraulic Gradient7.1 Because paper i
43、ndustry sludges are compressible, theirhydraulic conductivity is sensitive to the effective stress andhydraulic gradient applied during the test. Thus, the effectivestress and gradient should be set so that field conditions aresimulated as closely as possible. These conditions should bespecified by
44、the requestor. If no specification is required, thetest shall be conducted at an average effective confining stressin the range of 1535 kPa and a hydraulic gradient in the rangeof 1020.7.2 If the effective stress or hydraulic gradient in the field istoo low to be replicated in a flexible-wall permea
45、meter, thentests should be conducted at a series of three or more effectivestresses (or hydraulic gradients). Data from these tests are thenused to extrapolate back to the effective stress (sf)orhydraulic gradient (if) corresponding to the field condition.This procedure is illustrated in Fig. 1. Gra
46、phs such as thosemade in Fig. 1 are most effective when the effective stresses orhydraulic gradients are set as follows, where so(or io)isthelowest practical effective stress (or hydraulic gradient): so,33so,103so(or io,33 io,103 io).8. Termination8.1 The termination criteria described in section 9.
47、5 of TestMethods D5084 can be too stringent for hydraulic conductivitytesting of paper mill sludges.3The termination criteria de-scribed in the following can be used when testing papersludges. The method designations in this section are from TestMethods D5084.8.1.1 Open System (D5084 Methods A, B, C
48、, and D)Continue permeation until at least four values of hydraulicconductivity are obtained over an interval of time in which: (1)the ratio of incremental outflow to incremental inflow isbetween 0.7 and 1.3, and (2) the hydraulic conductivity issteady. The hydraulic conductivity can be considered s
49、teady iffour or more consecutive hydraulic conductivity determina-tions fall within 625 % of the mean for k $ 1 3 10-10m/s orwithin 650 % for k 1 kg).9. Procedure for Gradient Control in Variable HeadTests9.1 Because paper industry sludges are compressible, varia-tions in the hydraulic gradient during variable head tests(Methods B, C, and F in Test Methods D5084) can causesignificant variations in hydraulic conductivity. Thus, whentesting sludges, the head loss across the specimen shall bemaintained within 85 % of the maximum head loss applied atall times
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