1、Designation: D 7243 06aStandard Guide forMeasuring the Saturated Hydraulic Conductivity of PaperIndustry Sludges1This standard is issued under the fixed designation D 7243; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 associate
3、dwith 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 wastemono
4、fills. 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
5、of thesludge 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 c
6、omponent. 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 D 5084,Tes
7、t Methods 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 MethodsD 5084. The guide applies to specimens compacted in thelaboratory usi
8、ng procedures such as those described in TestMethods D 698 and D 1557 or undisturbed specimens col-lected from the field using procedures such as Practice D 1587or Practice D 7015.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespo
9、nsibility 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 a hazards section regarding the use of biocides(Section 10).1.5 This guide offers an organized collection of inf
10、ormationor 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 professionaljudgment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intended t
11、o 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 manyunique aspects. The word “Standard” in the title of thisdocument means only that the document has been approved
12、through the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12,400 ft-lbf/ft3(600kN-m/m3)D 1557 Test Methods for Laboratory Comp
13、action Charac-teristics of Soil Using Modified Effort (56,000 ft-lbf/ft3(2,700 kN-m/m3)D 1587 Practice for Thin-Walled Tube Sampling of Soilsfor Geotechnical PurposesD 2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD 3740 Practice for Minimum Requ
14、irements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 5084 Test Methods for Measurement of Hydraulic Con-ductivity of Saturated Porous Materials Using a FlexibleWall PermeameterD 7015 Practices for Obtaining Undisturbed Block (C
15、ubicaland Cylindrical) Samples of Soils1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.04 on Hydrologic Propertiesand Hydraulic Barriers.Current edition approved Nov. 1, 2006. Published January 2007. Originallyapproved i
16、n 2006. Last previous edition approved in 2006 as D 724306.2For referenced ASTM standards, 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.1C
17、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D 7100 Test Method for Hydraulic Conductivity Compat-ibility Testing of Soils with Aqueous Solutions3. Terminology3.1 DefinitionsFor common definitions of other terms inthis standard, see
18、 Terminology D 653.3.1.1 paper industry sludgeporous solid material derivedfrom clarification of water during wastewater treatment opera-tions at plants producing paper and similar materials. Alsoreferred to as paper sludge, papermill sludge, fiber clay, paperclay, or sludge.3.1.2 head loss, hLor ht
19、he 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, while the given distance is typically the length ofthe test specimen.3.1.3 permeameterthe apparatus (cell) containing t
20、he 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, stones, and filter paper; membrane; chamber;top and bottom plates; valves; etc.). However, the cell gener-ally does
21、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 hydraulicgradient and standard temperature conditions (20C).3.1.4.1 DiscussionThe term coeffcient of permeability (or
22、permeability) 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 guide is intended to supplement the methods andprocedures described in Test Methods D 5084. When followingthe recom
23、mendations in this guide to test paper sludges, allassumptions and limitations described in Test Methods D 5084apply.4.2 This guide only applies to hydraulic conductivity testson paper industry sludges where one-dimensional laminar flowof water is imposed using a flexible-wall permeameter.4.3 The hy
24、draulic conductivity of sludges, and other porousmaterials, generally decreases as the degree of water saturationdecreases. This guide applies only to water-saturated sludgecontaining negligible amounts of gas.4.4 This guide applies only to permeation of paper industrysludges with water. Information
25、 on testing porous materialswith liquids other than water can be found in Test MethodD 7100.4.5 The hydraulic conductivity of paper sludge measured inthe laboratory following Test Methods D 5084 and the recom-mendations in this guide may or may not be comparable to thehydraulic conductivity of in-pl
26、ace 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 produced when using the recommen-dations in this guide depends on the competence of the personnelperforming the te
27、sting and the suitability of the equipment and facilitiesthat are employed. Agencies that meet the criteria of Practice D 3740 aregenerally considered capable of competent and objective testing, sam-pling, inspection, etc. Users of this guide are cautioned that compliancewith Practice D 3740 does no
28、t in itself ensure reliable results. Reliableresults depend on many factors; Practice D 3740 provides a means ofevaluating some of those factors.5. Reagents5.1 Permeant Water:5.1.1 Selection of the permeant water should follow theinstructions in Section 6 of Test Methods D 5084. Comparativetesting h
29、as 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 same hydraulic conductivity is obtained ifhydraulic conductivity tests on paper sludge are conductedwith tap wa
30、ter, 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 the permeantwater to prevent generation of gases associated with microbialactivity. Testing conducted previ
31、ously3suggests that biocidesdo not alter the hydraulic conductivity of paper sludges whenused at concentrations recommended by the manufacturer.However, comprehensive testing has not been conducted toassess how all biocides affect the hydraulic conductivity ofpaper sludges (for example, through chem
32、ical 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. Procedures to Minimize Gas Generation6.1 Gases generated by microbial activity can confoundhydraulic conductivity
33、 testing of paper sludges. Indications ofgas generation include: (1) inability to meet the terminationcriteria in Test Methods D 5084 for steady hydraulic conduc-tivity and continuity (section 9.5 in Test Methods D 5084), (2)flow in the influent system in the opposite direction of theapplied hydraul
34、ic 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 microbial activity or by applyingelevated backpressure.6.2.1 Microbial activity can be minimized by temperaturecon
35、trol 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 than 4C. Akitchen refrigerator works well for this purpose. The tempera-ture of the chamber should be con
36、trolled to within 61C andmust be maintained above 0C at all times. At lower tempera-tures, the effects of temperature on the viscosity and density of3Nelson, M., and Benson, C., “Laboratory Hydraulic Conductivity TestingProtocols for Paper Sludges Used for Hydraulic Barriers,” Technical Bulletin No.
37、848, National Council for Air and Stream Improvement, Research Triangle Park,NC, 2002.D 7243 06a2water reduce the hydraulic conductivity. Thus, when tempera-ture is used to control microbial activity, the hydraulic conduc-tivity must be adjusted to standard conditions (20C) using themethod described
38、 in section 10.3 of Test Methods D 5084.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. DOWICIL (2,2-dibromo-3-nitrilopropionamide) has been found effective at preventing gasgeneration when
39、 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 testing with tap wateralone under cool conditions that limit microbial activity (asdescribed in sectio
40、n 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 microbial activity can be suppressedusing elevated backpressure. The backpressure required tosuppress gas ge
41、neration can be determined by incrementallyincreasing the backpressure as described in section 9.3 of TestMethods D 5084 followed by observation of the inflow andoutflow for two or more days. The backpressure is sufficientwhen the adverse affects caused by gas generation (describedin section 6.1) ar
42、e 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 industry sludges are compressible, theirhydraulic conductivity is sensitive to the effective stress and
43、hydraulic 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 the requestor. If no specification is required, thetest shall be conducted at an average effective con
44、fining 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 permeameter, thentests should be conducted at a series of three or more effectivestresses (or hydraulic grad
45、ients). 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. Graphs such as thosemade in Fig. 1 are most effective when the effective stresses orhydraulic gradients a
46、re 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 9.5 of TestMethods D 5084 can be too stringent for hydraulic conductiv-ity testing of paper mill sludges
47、.3The termination criteriadescribed in the following can be used when testing papersludges. The method designations in this section are from TestMethods D 5084.8.1.1 Open System (D 5084 Methods A, B, C, and D)Continue permeation until at least four values of hydraulicconductivity are obtained over a
48、n 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 steady iffour or more consecutive hydraulic conductivity determina-tions fall within 625 % of the me
49、an 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 D 5084) 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 during the test.10. Hazards10.1 All warnings described in Test Methods D 5084 applywhen following t
