Decision Support Tool- Giving transparency and justification in weathered hydrocarbon remediation

Transcription

1 Decision Support Tool- Giving transparency and justification in weathered hydrocarbon remediation

2 The remediation market Remediation designs and practices are not commonly integrated with SI Companies Many Remediation companies have limited portfolio of techniques The market is conservative to technology Licence issues may be confusing Fit for purpose- says who?

3 What would make on site ex situ bioremediation a more attractive option? Certainty Can I meet target values? Informed assessment Can I do something to increase the rate of degradation or the nature of the end-product Sustainable Economic Environmental Transparency for selection of technology If I rank it against the competing technologies; is it the best?

4 Where is the market status at the moment? Test cases demonstrate success Cost benefit is unclear at the moment Few laboratories facilitate in decision making process Integrated thinking is absent- from the Phase 1 through to the re-use of the materials

5 Predicting Success Physical Structure, PSA, moisture holding capacity Biological Microbial numbers and activity, performance of degraders, confirm habitat suitability Chemical Total and bioavailable hydrocarbon, cocontaminants, nutrients

6 These features can be integrated with empirical testing AtRemedios we developed a set of tests for predictive degradation These have been applied to 50 test sites with incredible success rates The key attributes are biological and chemical but these are then overseen in a physical and engineering context

7 Resp [TPH] BF = (I x [TPH] x x log (MPN) Inhibition BF = bioremediation function I = induction [TPH] =TPH concentration MPN = most probable number Resp = respiration

8 BF & Rate of Degradation Rate (mg/kg/day) e+1 1e+2 1e+3 1e+4 1e+5 1e+6 1e+7 1e+8 BF

9 BF & Rate of Degradation Rate (mg/kg/day) e+1 1e+2 1e+3 1e+4 1e+5 1e+6 1e+7 1e+8 BF

10 What does this mean? 60 Hydrocarbon concentration (mg/kg) Bioremediation Days

11 This is a single product.. The purpose of was not to champion a single product And this Remedios algorithm is just a single step in the refinement of remediation success Require to assess the wider market and all the techniques available

12 So what is on the market to help us? Guidance documents Lack specificity and flexibility The Battelle and USEPA books and documents Been around a while and have not evolved A few software systems to support decision but these are very data heavy programmes Racer is $5k and requires enormous amount of data and doesn t help decision making

13 So what is on the market to help us?

14 What do Regulators and Insurers Seek? An explanation of how decisions were made Justification that the technique will meet the clean-up criteria Holistic assessment of the full process

15 Enables a transparent justification of the suitable technology from the outset of site works Gives focussed and streamlined support for targeting best options Interfaces with the web to enable continual updating as practices become established and lessons are learned

16 A multi-tier approach Risk Based Management Tree Meet Client Objectives & Liase With Regulators CSM Screening Assessment Confirmation & Evaluation Of Model Remediation & Monitoring Non Detailed Risk Assessment - Site History Established, COCs Unknown No Assess Site Conditions Yes Preliminary Risk Assessment Undertaken? Yes Is There Potenitial Risk i.e. Pathway Present? Yes Undertake Generic Quantitative Risk Assessment Input Generic Assumptions (GACs) Exposure Risk? Yes Undertake Site Specific Risk Assessment Input Site Specific Assumptions (SSACs) Exposure Risk? Yes Develop Sampling Strategy Conduct SI Using Developed Strategy COCs Identified COCs - Exceedance Of Screening Values (SSAC)? Yes Evaluate Potential Remedial Options Design Appropriate Remedial Action Plan Implement Remedial Action Plan Monitor For Effectiveness No No No INPUT No Further Action INPUT No Further Action No Further Action Tier 2 Site Sign Off Phase I - Desk Study & Site Walk-Over Phase II - Intrusive Site Investigation & Analysis Of Generated Data Phase III - Choice & Implementation Of Remediation Strategy Tier 1- places in the context of a riskbased framework Tier 2- evaluates all the suitable comparative options Tier 3- aids the decision making for optimisation

17 Tier 2 Permissibility and certainty Applicability Permissibility Certainty Economic and duration Capital Operations and maintenance Market constraints Remediation duration Environmental credit

18 Applicability (1-3) Permissibility (1-3) Certainty (1-3) Capital (1-5) Site Size <1000t Site Size <1000t Site Size <1000t Site Size <1000t Leave Do Nothing Monitor In Situ Biological Bioventing Enhanced Bioremediation Phytoremediation In Situ Physical/Chemical Treatment Chemical Oxidation Electrokinetic Separation Fracturing Soil Flushing Soil Vapour Extraction Solidification/Stabilization Soil, Sediment, Bedrock and Sludge Treatment Technologies In Situ Thermal Treatment Thermal Treatment Biopiles Composting Ex Situ Biological Treatment Landfarming Slurry Phase Biological Treatment Windrowing Ex Situ Physical/Chemical Treatment (Assuming Excavation) Chemical Extraction Chemical Reduction/Oxidation Dehalogenation Separation Soil Washing Solidification/Stabilization Ex Situ Thermal Treatment (assuming excavation) Hot Gas Decontamination Incineration Open Burn/Open Detonation Pyrolysis Thermal Desorption Landfill Cap Tonnage Of Contaminated Soil..???? S/M/L Landfill Cap Enhancements/Alternatives Other Treatment Excavation, Retrieval, and Off-Site Leave Do Nothing Monitor Insitu Biological Treatment Enhanced Bioremediation Monitored Natural Attenuation Phytoremediation Ground Water, Surface Water, and Leachate Treatment Technologies In Situ Physical/Chemical Treatment Air Sparging Bioslurping Chemical Oxidation Directional Wells Dual Phase Extraction Thermal Treatment Hydrofracturing Enhancements In-Well Air Stripping Passive/Reactive Treatment Walls Ex Situ Biological Treatment Bioreactors Constructed Wetlands Ex Situ Physical/Chemical Treatment (Assuming Pumping) Adsorption/Absorption Advanced Oxidation Processes Air Stripping Granulated Activated Carbon (GAC)/Liquid Phase Carbon Adsorption Ground Water Pumping/Pump and Treat Ion Exchange Precipitation/Coagulation/Flocculation Separation Sprinkler Irrigation Containment Physical Barriers Deep Well Injection Air Emissions/Off-Gas Treatment Biofiltration High Energy Destruction Membrane Separation Oxidation Scrubbers Vapour Phase Carbon Adsorption

19 Part A has shown that on site ex situ is a suitable option Chemical ph Are there factors that can be further amended and manipulated to optimise the remedial process? Nutrient requirements What is the concentration of carbon mg/kg associated with TPH (insert value) For each 100 units of C add 12 units of N and one of P We recommend that only 50 % of the N dose is added at this stage and the other is irrigated in (calculate dose on N and P to add) Bioavailability assay Tier 3A Physical Has a degradation bioassay been carried out? Has a chemical bioavailability assay been conducted? Goodcontinue with the process Did it use alcohol Did it cyclodextrin, TENAX or XAD? Did the residual soil after extraction have a concentration that exceeded the SGV or SSAC? Yes Was the residue a wide range of TPH? Was there other forms of carbon competing? No Yes You may need to reconsider future use of the site Yes Was the residue mainly recalcitrant PAHs? Would enhanced bioavailability enable SGV to be met?- if so add solvent or surfactant

20 Algorithm calculated to assess most suitable set-up Microcosm Microcosm experiment used to verify algorithm Defined Targets Olfactory Risk-based Physical/ engineering Tier 3B Constructed Biopile Specific Analysis Routine Analysis Nutrient Amendment Verify bioavailable status in KCl Biosensor Analysis Use MeOH Verify presence of toxic and water to metabolites or co-pollutant assess bioavailability of co-pollutant Physical constraints and TPH Trial pits to make sure the biopile is homogenised MPN A count of Assessment of Bioaugmentation less than 10 4 If the biopile was amended or is too low and not,there should be a minimum re- number of degraders present augmentation is requirted TPH Measurements Analysis carried out with calibrated FID CO Measurements 2 Gas Analysis O 2 Measurements Gas Analysis Percent WHC Derived from moisture ph In water Temperature Using probe None of the above The cause of reduced degradation rate cannot be related to one of the above factors Levels change as expected by algorithm WHC Confirm the values are between 60 and 80% ph Make sure or amend: check buffering Temperature If the temp is too low (<10) then add steam; too high (>40) remove covers. YES NO Continue monitoring Plot data To assess trends Turning If the system is air limited then turn Moisture Add/ remove as required ph Trickle filter to adjust Temperature Assess site weather and forecasts

21 Technology and techniques are supported by web information Profile enables ease of updating Initial focus on bioremediation being progressed Transparent support of screened materials on the web Test validation performed