Presentation on theme: "INNOVATIVE & INTEGRATED APPROACH TO HEAVY METAL REMEDIATION"— Presentation transcript:
1 INNOVATIVE & INTEGRATED APPROACH TO HEAVY METAL REMEDIATION H2O 2014ShanghaiNovember 14, 2014
2 AgendaOverviewGoals and ObjectivesRemediation Approach
3 Overview China’s fast socio-economic development since the 1980s capital and resource-intensive – negative environmental and health impactstough challengeS - natural resource depletion, pollution and environmental degradationRapid urbanization in recent years has resulted in the need to redevelop industrial land once occupied – and contaminated – by old industries, which have helped bring the issue of the remediation and redevelopment of contaminated lands (often referred to as brownfields) to the forefrontBrownfields pose two categories of problems:environmental and public health risksobstacles to urban and local economy development, particularly if ultimately they remain unused.
4 COMMON Contaminants:Heavy metalsOrganic contaminantsPersistent organic pollutants (POPs)Environmental and health risks:SoilGroundwaterSurface hazardsOngoing liability
5 Heavy metals sources Exposure pathways iNDUSTRIAL waste AGRICULTURAL – bad fertilizerMining – acid mine drainageExposure pathwaysAirborne emissionsWaste disposalWastewater dischargeSludge depositsSoil contamination at manufacturing sitesGroundwater pollution through infiltration of pollutants
6 Goals Integrated technical framework Pollution management Reduce public exposure to contaminated landSustainable natural resource managementSafe redevelopment
7 Objectives (Brownfield Site) Demolition of structures at remediation sitesConstruction of remediation infrastructureAccess roadsWater managementSoil and groundwater cleanupTreat soil and sedimentsClose dump siteRemove and dispose of industrial waste
8 Future Land Use considerations Industrial & manufacturing facilityGovernment complexesresidentialCommercialRecreational activitiesEco-parkConstructed lake/wetland area
9 Project TeamEasen – Specializes in soil, water, mine, and industrial waste remediation. Easen offers a complete spectrum of services from site characterization through in situ and ex situ application of remediation technologies.EnviroLogek - Specializes in the development and application of environmental investigation and remediation technologies on five continents since 1998.ReSolution Partners – Specializes in remediation design and the development of treatment technologies for heavy metals and organic compounds since 1994.
10 Team Capabilities Site characterization/investigation Remediation designCreative remedial optionsFocus on sustainable solutionsIntegrate remediation with redevelopmentCost-effective remediesRegulatory goals and appropriate test methodsTreatability studiesReagent supplyInfrastructureImplementation of selected remediesSite closure
11 High Resolution Site Characterization Technology (HRSC) Quickly Identify Contaminant Mass Location Vertically & HorizontallyIdentify Contaminant Mass Location in Reference to Subsurface LithologyDefine Subsurface Lithology in Relation to Optimal Application & Injection HydraulicsMembrane interface probeHydraulic profiling toolUltra-violet optical screening tool
12 Typical Test Methods - Metals Toxicity Characteristic Leaching Procedure (TCLP)Synthetic Precipitation Leaching Procedure (SPLP)Site-specific leaching procedures (SSLP with groundwater, waste water)Multiple Extraction Procedure (MEP)Physiologically Based Extraction Test (PBET)familiar with test methods in China and has performed treatability studies on China soils.
14 Treatment Options - Groundwater Bioremediation for organicsPump & treat for control of dissolved metal and organic contaminantsPermeable reactive barriers (containment)IronZeolite / Ion exchangeReagent injectionStabilization of metalsOxidation of organic compoundsZero valent iron
15 CHEMICAL REAGENT TECHNOLOGY IS A COMBINATION OF AN ENGINEERED SOLUTION, APPLICATION KNOW-HOW AND UNIQUE REAGENTSSPECIALLY FORMULATED BASED ON WASTE PROFILEADDED TO METAL-LADEN SOIL AS POWDER OR INTO THE GROUND AS A SLURRY SOLUTIONSEQUESTERED WITHIN THE FINE PARTICLES OF THE PRODUCT AS INSOLUBLE MINERALSNEUTRALIZES ACIDITYTRAPPED BY ADSORPTION - HIGH SURFACE-TO-VOLUME RATIO AND A HIGH CHARGE-TO-MASS RATIOPRECIPITATION, CO- PRECIPITATION, AND ISOMORPHOUS SUBSTITUTION REACTIONS (I.E., INCREASINGLY FORMED BY RECRYSTALLISATION PROCESSES).
16 Implementation Methods Reagents can be applied in situ or ex situ in InjectionMechanical mixingTrenching (Permeable reactive barriers)Reagents can be applied in situ or ex situ inDry, granular formAs a solution, or slurry
17 IN-SITU REAGENT DELIVERY HIGH-PRESSURE INJECTION VIA DIRECT PUSH METHODOLOGYINJECTION PARAMETERS:CONCENTRATION OF CONTAMINANT(S) IN SOIL (MG/KG) & GROUNDWATERSOIL POROSITY & HYDRAULIC CONDUCTIVITYVOLUME OF WASTE TO BE TREATED - LITRES OF WATER AND M3 OF SOIL TO BE TREATEDTOTAL ACTUAL ACIDITY (TAA) AND TOTAL POTENTIAL ACIDITY (TPA)CONFIDENCE FACTOR (E.G., CONTAMINANTS, LITHOLOGY, HYDROGEOLOGY, DISTRIBUTION FACTORS, CONTACT TIME AND DELIVERY METHODS)TOTAL REAGENT VOLUME TO BE APPLIED
18 Engineering Control For Optimal Injection Pressure Q/A=Keffective (Pinjection-ρwater gh)/hWhere:Q/A = the flow rate applied over the area of the expanding mound.Vertical flow ceases as the mound height (h) reaches the pressurelimit or the selected “not to exceed” injection pressure.Keffective= Vertical Hydraulic conductivityPinjection = 60% of the allowable injection pressureρwater = Density of waterg = Gravitational accelerationh = mound height above water table
19 Soil Washing Fast, high throughput soil remediation and soil recycling Matrix Enhanced Treatment: able to treat up to 150 different contaminantsWet Extraction Source Treatment: able to treat moisture rich soils including clays, sediments and drill cuttingsWorks with a wide variety of reagents, surfactants, oxidantsMobile units capable of treating 40 to 320 tons/hour
21 Sustainable Remediation Alternative - Metals Traditional ApproachSustainable AlternativeExcavation of metals- contaminated soil from siteBackfill site with clean fillDispose as hazardous wasteHaul hazardous materials to limited landfill locations (increased carbon footprint)Chemically stabilize metals to render non-hazardousPotentially reuse stabilized soilDispose as non-haz materialMore disposal options locally for solid waste management (non-hazardous)
22 Comparing Options: 1. Off-Site Hazardous Waste Metals in soil that exceed a regulatory limitHigh cost management optionReadily accepted by regulatorsLimited disposal locations
25 What is metals stabilization? Add reagents to form minerals in soil and aquifers to reduce:Leaching from soilGroundwater concentrationsToxicityReagents are typically:Common agricultural and industrial productsPose little to no hazard to the environment
26 Stabilization Reagent Examples - Metals Phosphates: mineral formation (Pb)Iron: adsorption (As), co-precipitation (As, Ni), reduction (Cr)Sulfide: mineral formation (Hg, As, Pb), reduction (Cr)pH: mineral formation, adsorption (Pb, Cd)Biological/carbon: reduction, adsorption (Cr, As, Se)Proprietary reagents typically based on above, singly or in combination.
27 Case Study - Demonstration Project, Changsha Site, April 2014 Leachable chromium concentration reduced from 3.79 to trace level in 24 hours after treatment
28 Remediation Approach Review available site data Discuss specifics of future land useIntegrate information into preliminary remediation designDevelop site characterization/investigation workplan that supports project goals
29 Remediation Approach (cont.) Implement site investigationPerform treatability studySummarize preliminary resultsDiscuss remediation goals and test methodsFinalize treatment programPrepare findings and conclusions for review of remedial optionsFinalize remediation design and workplanImplement approved remediation workplan
31 Site Design Goals 5-10 different remediation models/approaches Tailored remediation to specific site characteristicsFlexibility to change from one remediation and restoration approach to another based on future land use
32 Fully-Integrated Project Team Site CharacterizationRemediation DesignTreatability StudiesTreatment Reagents/MethodsTurn-key Implementation