1、Quantification of Vapor Phase-related Natural Source Zone Depletion ProcessesAPI PUBLICATION 4784 FIRST EDITION, MAY 2017Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be
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9、Street, NW, Washington, DC 20005.Copyright 2017 American Petroleum InstituteForewordNothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neithe
10、r should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.The verbal forms used to express the provisions in this document are as follows.Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform
11、to the standard.Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the standard.May: As used in a standard, “may” denotes a course of action permissible within the limits of a standard.Can: As used in a standard, “can” de
12、notes a statement of possibility or capability.iiiContentsPage1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . .
13、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Document Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 Intended Audience and Use . . .
14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.4 Guidance Applicability and Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.5 Document Content Ref
15、erence Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.6 Data Uses for NSZD Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.7 Site Applicabilit
16、y and Technology Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Theory of NSZD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.1 Att
17、enuation Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.2 Thermal Signatures of Biodegradation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、. . 162.3 Estimation of Natural Source Zone Depletion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 General NSZD Evaluation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.1
19、 Program Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.2 Gas Flux Monitoring Field Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.
20、3 Data Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Gradient Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、. . . . . . . . . . . . . . 304.1 Method Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.2 Program Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、. . . . . . . . . . . . . . . . . . . . . . . 314.3 Field Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364.4 Data Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 Passive Flux Trap Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415.1 Description. . . . . . . . . . . . . . . . . . . . . .
24、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415.2 Program Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415.3 Trap Deployment and Retrieval
25、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435.4 Data Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 Dynamic
26、Closed Chamber Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . 476.2 Program Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486.3 Survey Implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28、. . . . . . . . . . . 506.4 Data Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 Emerging Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . . . . . . . 547.1 Biogenic Heat Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547.2 CH4Flux Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 587.314C Isotopic Correction for the Gradient and DCC Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 598 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 608.1 Key Points of Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 608.2 Future Research Needs . . . . . . . . . . . . . . . . . .
32、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61Annex A (informative) Example Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63Annex B (informative) Case Study of Three NSZD Est
33、imation Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110Figures1-1 Conceptualization of Vapor Phase-rel
34、ated NSZD Processes at a Petroleum Release Site . . . . . . . . . . . . 62-1 Conceptualization of Saturated Zone NSZD Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10vContentsPage2-2 Conceptualization of Vapor Phase-related NSZD Processes . . . . . . . . . .
35、 . . . . . . . . . . . . . . . . . . . . . . . . . 122-3 Conceptualization of Vapor Phase-related NSZD Processes (a) with and (b) without Hydrocarbon Impacts in the Vadose Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153-1 Example Use of No
36、mograms to Estimate NSZD Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213-2 Example Placement of Survey Locations for DCC Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253-3 Example Conceptual Depiction of Site-wide NSZD Rat
37、e Contouring . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294-1 Schematic of Gradient Method Monitoring Setup with (a) and without (b) Hydrocarbon Impacts in the Vadose Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38、 . . . . 334-2 Conceptualization of Soil Gas Concentration Profiles with (a) and without (b) Hydrocarbon Impacts in the Vadose Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344-3 Choice of Measurement Points and Influ
39、ence on Estimated Gradient CO2Gradient in Soil with (a) and without (b) Hydrocarbon Impacts in the Vadose Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354-4 Determination of b Parameter in Equation 4.2 from Nonreactive Tracer Test Measurements of Mass and Vapor Recovery (Excerpt
40、from Johnson et al. 1998) . . . . . . . . . . . . . . . . . . 385-1 Schematic (Left) and Photo (Right) of a Passive CO2Flux Trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426-1 LI-COR 8100A DCC Apparatus and Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41、. . . . . . . . . . . . . . . . . . . 486-2 Example Output from a CO2Efflux Measurement Using a DCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537-1 Schematic Diagram of NSZD-derived Heat Flux and a Subsurface Thermal Profile . . . . . . . . . . . . . . . . 56B-1 Site Layout a
42、nd Locations of NSZD Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92B-2 Cross Section A-ASoil Texture, LNAPL Occurrence, and NSZD Monitoring Locations . . . . . . . . . . . 93B-3 Soil Gas Concentration Depth Profile at NSZD-1 . . . . . . . .
43、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97B-4 Soil Gas Concentration Depth Profile at NSZD-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97B-5 Soil Gas Concentration Depth Profile at NSZD-3 . . . . . . . . . . . . . . .
44、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98B-6 Soil Gas Concentration Depth Profile at NSZD-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98B-7 Estimated Hydrocarbon Degradation Rate Using Depth and Porosity . . . . . . . . . . . . . .
45、 . . . . . . . . . . . . 100B-8 Estimated Hydrocarbon Degradation Rate Using Effective Oxygen Diffusion Coefficient and Depth 101B-9 Passive Flux Trap CO2Efflux Measurement Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105B-10 DCC Results Compared with Soi
46、l Moisture and Ambient Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 107B-11 Comparison of NSZD Rate Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108Tables1 Summary of Intended Uses for This Guidance . . . . . .
47、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Document Overview and Content Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-1 Summary of Site Conditions that Preclude or Affect Vapor Phase-relate
48、d NSZD Monitoring . . . . . . . . . 73-1 Summary of Key LCSM Elements and Their Relations to NSZD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183-2 Spectrum of Data Use Objectives and the Associated Scope of NSZD Monitoring . . . . . . . . . . . . . . . . . 193-3 NSZD Monitoring
49、Method Screening Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233-4 Units of NSZD Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273-5 Example Representative Hydrocarbons and CO2 Flux Stoichiometric Conversion Factors . . . . . . . . . 284-1 Sources of Uncertainty, Variability, and Mitigations Associated with the Gradient Method . . . . . . . . . . 375-1 Sources of Uncertainty, Variability, and Mitigations for the Passive Flux Trap Method .
