【国外标准】 Standard Test Methods for Estimating the Permanganate Natural Oxidant Demand of Soil and Aquifer Solids

5.1 Test methods A and B are used to estimate the permanganate natural oxidant demand exerted by the soil or aquifer solids by determining the quantity of potassium permanganate that is consumed by naturally occurring species as a function of time. Test Method C is used to estimate the permanganate total oxidant demand exerted by soil, aquifer solids, chemical contaminants or any other reduced species by determining the quantity of potassium permanganate that is consumed by all components of the bulk aquifer as a function of time. Typically, the measurement of oxidant demand is used to screen potential sites for in situ chemical oxidation (ISCO) with permanganate (Test Methods A and C) and provide information to aid in the design of remediation systems (Test Methods B and C).5.2 While some oxidizable species react relatively quickly (that is, days to weeks), others react more slower (weeks to months). Consequently, the PNODt is expected to be some fraction of the PNODmax.5.3 For ISCO injection applications, the PNOD may overestimate the demand exerted due to mass transport related issues. For soil blending applications, the PNOD is a more accurate measure of the demand exerted due to better mass to oxidant contact.NOTE 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/and so forth.1.1 These test methods cover the estimation of the permanganate natural oxidant demand (PNOD) through the determination of the quantity of potassium permanganate (KMnO4) that organic matter and other naturally occurring oxidizable species present in soil or aquifer solids will consume under specified conditions as a function of time. Oxidizable species may include organic constituents and oxidizable inorganic ions, such as ferrous iron and sulfides. The following test methods are included:Test Method A—48-hour Permanganate Natural Oxidant DemandTest Method B—Permanganate Natural Oxidant Demand KineticsTest Method C—Permanganate Total Oxidant Demand1.2 These test methods are limited by the reagents employed to a permanganate natural oxidant demand (PNOD) of 40 g KMnO4 per kg soil or aquifer solids after a period of 48 hours (Methods A and C) or two weeks (Method B).1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to interpret the results of the data. It is the responsibility of the user of this standard to interpret the results obtained and to determine the applicability of these results prior to use.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 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.