ASTM_D_5919_-_96_2011.pdf

Designation:D591996(Reapproved 2011)Standard Practice forDetermination of Adsorptive Capacity of Activated Carbonby a Micro-Isotherm Technique for Adsorbates at ppbConcentrations1This standard is issued under the fixed designation D5919;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last 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 This practice covers the assessment of activated carbonfor the removal of low concentrations of adsorbable constitu-ents from water and wastewater using the bottle point isothermtechnique.It can be used to characterize the adsorptiveproperties of virgin and reactivated activated carbons.1.2 This practice can be used in systems with constituentconcentrations in the low milligrams per litre or microgramsper litre concentration ranges.1.3 This practice can be used to determine the adsorptivecapacity of and Freundlich constants for volatile organiccompounds provided the handling procedures described in thispractice are followed carefully.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 The following safety caveat applies to the proceduresection of this practice:This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD3370 Practices for Sampling Water from Closed ConduitsD2652 Terminology Relating to Activated CarbonD2867 Test Methods for Moisture in Activated Carbon3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice relating toactivated carbon,refer to Terminology D2652.3.1.2 For definitions of terms used in this practice relating towater,refer to Terminology D1129.4.Summary of Practice4.1 This practice consists of the determination of the ad-sorptive capacity of activated carbon for adsorbable constitu-ents by contacting the aqueous solution contained in anessentially zero head space container with activated carbon,determining the amount of the constituents removed,andcalculating the adsorptive capacity and the Freundlich con-stants,K and 1/n,from a Freundlich isotherm plot.4.1.1 The weights of activated carbon used in this practicemay have to be adjusted to achieve reasonable levels ofremoval of the constituent.The best data is obtained whencarbon dosages are selected that result in no more than 90%orno less than 10%of the adsorbable constituents being removedfrom the water by the carbon.4.1.2 If carbon dosages used are less than 1 mg,largervolumes of the aqueous solution may be used,such as 1000mL.5.Significance and Use5.1 This practice allows the adsorption capacity at equilib-rium of an activated carbon for adsorbable constituents presentin water to be determined.The Freundlich K and 1/n constantsthat can be calculated based upon information collected usingthis practice can be used to estimate carbon loading capacitiesand usages rates for the constituent present in a water stream atother concentrations.6.Interferences6.1 The water shall not contain any nondissolved compo-nents.6.2 The presence of naturally occurring organic compoundssuch as humic acids in the water being studied may signifi-cantly affect the ability of the carbon to adsorb the constituent1This practice is under the jurisdiction of ASTM Committee D28 on ActivatedCarbon and is the direct responsibility of Subcommittee D28.02 on Liquid PhaseEvaluation.Current edition approved March 1,2011.Published May 2011.Originallyapproved in 1996.Last previous edition approved in 2006 as D5919 96(2006).DOI:10.1520/D5919-96R11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 of interest.Results obtained when using water other thanreagent grade water may be unique for the particular waterused and it may not be possible to apply these results to otherwater systems.6.3 The adsorption isotherm data collected using this prac-tice can be affected by the ionic strength,pH and temperatureof the water,and the presence and growth of microorganisms.7.Apparatus7.1 Equilibrator(or other rotating mixing device),a rotatingdevice operating at 25 rpm which can rotate the isothermbottles end over end ensuring good dispersion of the powderedactivated carbon in the water being treated.7.2 Grinding Mill,capable of grinding