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The project “protection ofgroundwater at industrialcontaminated sites”, PURE, (EU code: EVK1-CT-1999-00030)has been carried out in the 5th Framework program.
PURE has been aimed atpreventing contamination ofgroundwater from industrial sitesfrom priority pollutants, includingrecalcitrant chloroorganics, BTEX,PAH, and heavy metals. Theproject had as objectives to:– Develop a set of tools and
methods to characterize a siteand follow the efficacy ofremedial actions;
– Provide innovative remediationtechniques to prevent thegroundwater pollution atindustrial sites;
– Develop a methodology toevaluate costs and benefits assupport for an optimal choice of remedial actions;
– Enhance the discussion betweenthe relevant actors (science,industry, service providers) toreach the best approach toprotect groundwater.
Structure and contentsPURE is structured in two sub-projects, SICHAMORE (SIte CHAracteri-sation and MOdelling for REme-diation) and TREES (Techniques for Remediationof Earnest Environmentalcontaminants in Soil and ground-water). Much effort was given toconverge the contents of the twoparts and to make sure that theresults of the differentworkpackages fitted into one another.
The integration of the work-packages forms the basis of SCAR (Site CharacterizationApproach for Recovery ofcontaminated industrial sites).SCAR was constructed in responseto the suggestions of the industrialpartners and service providers togive overview and a set-up for abest practice.This brochure will describe brieflythe outcomes of the PURE projectper workpackage and the integra-tion of the workpackages withinSCAR.
1 TNO Environment, Energy and Process Innovation
WP4 Degradation of chlorinated compoundsand Heavy metal stabilization
WP5 Electro-bioremediation
WP6 Coupled degradation ofmixed contaminants
WP7 Simultaneous remediation of saturated& Unsaturated zone
WP8 Co metabolism with methane/butaneoxidizers
WP1 Assessment of Benefits and Costsand site characterization
WP2 Development of field-basedmeasurement tools
WP3 Site characterization and modelling
TREESTechniques for Remediation of Earnest
Environmental contamination in Soil and GroundwaterSICHAMORE
SIte Characterization and MOdelling for REmediation
PUREProtection of GroUndwater Resources at industrially contaminated sites
PUREWP Project management, Integration and converging ideas
SCARSite Characterisation Approach for Recovery of contaminated data
The SICHAMORE workpackageswere designed to develop newmethods and techniques toefficiently characterize thecontaminated site.
The site data were used as basisfor the evaluation of feasibleremedial techniques.
SICHAMORE
PURE; Protection of groundwater resources
at industrially contaminated sites
PURE; Protection of groundwater resources at industrially contaminated sites
In Europe, industrial sites areoften operational for a long timeand unravelling their history isnot always easy. Moreover,combinations of multiplecontaminants in a complex sub-surface exist quite regularly.
To obtain more insight on optionsfor remediation techniques andtheir cost-effectiveness, a decisionsupport tool has been developed,called: ABC or assessment ofbenefits and costs. It is seen as atechnical tool to identify andexamine the feasibility of differentremediation techniques, inparticular to highlight possibilitiesfor alterative approaches to con-ventional techniques. It is seen as acommunication tool to compareremediation scenarios and to scoretheir comparative benefits. It isseen as a learning tool and aneconomic tool to evaluate costeffectiveness, duration and use ofspace. The information inputs to theassessment module are:
contaminated area (ha), use (highuse with low accessibility versuslow use), groundwater depth,groundwater velocity, type ofcontaminant, depth ofcontaminants, source versusplume, geology (sand / mixed /clay), saturated versus unsaturatedzone. Contaminants arecategorised on the basis of theapproaches to their remediation, asfollows: benzene, naphthalene andvolatile oil; TEX; phenols andstyrene; other PAH and heavy oil;metals; cyanide; low chlorinatedvolatile hydrocarbons; lowchlorinated non-volatilehydrocarbons; high chlorinatedvolatile hydrocarbons; highchlorinated non-volatilehydrocarbons.
Benefits are evaluated using lifecycle analysis (LCA) on a cradle tothe grave basis. Also environmentalmerit (cleaned medium times aclean-up factor), duration anddeployment of space are included.
Cost data and outputs encompassa cost estimation for eachtechnique by country. Cost dataare relatively coarse because theyare specific to countries, and alsohighly site specific.Output of the ABC tool is a set oftables and graphs with informationabout energy, resource require-ments, emissions and (hazardousand non-hazardous) waste. Resultson the ‘environmental score’, timeduration, deployment of space,costs and additional expert remarksare also displayed in the output. The decision maker at the plantoperational level can start with thedecision analysis activity once anoverview of information relevant tothe nature of the decisions isavailable. A fast simple assessmenthas to be made in a first phase ofthe project resulting in a risk,benefit and cost analysis. Theremediation will be optimised interms of technical, financial andtiming criteria and to meet bothinternal and external constraints.
2
WP1: ABC Assessment of benefits and costs
L. Maring and A.J.C. Sinke
TNO Environment, Energy and Process Innovation, P.O. Box 342, 7300 AH Apeldoorn, The Netherlands
INPUT:
site description, hydrology &
contaminant situation
OUTPUT:
energy, emissions, waste,
resources, time, deployment of
space, environmental score,
costs, remarks
PURE; Protection of groundwater resources at industrially contaminated sites
Several sensor techniques havebeen developed and tested tocontribute to a cost effectivesampling strategy atcontaminated sites. Within thePURE project, sites with differentmixtures of contaminants werethe focus and different types ofsensors have been developed forin-situ measurements.
Lux biosensorThe primary aims were to identifycontaminant hot spots during initialsite screening and to monitor theefficacy of ongoing remediationprogress. A small field-applicablePC-based discrete sampleinstrument using lux biosensors forrapid site screening was thereforedeveloped and validated. Themachine was successfully used toassess toxicity, and provide toxicitycontour plots diagnostic ofremediation progress.The instrument was found to havethe potential to discriminatebetween groups of groundwatercontaminants and identify the classof contaminant during initial sitescreening. Consequently, neuralnetworks and other data treatmentmethods have been applied inorder to develop a means ofautomated contaminant classidentification.The luminescence-based biosensorswere successfully used to assessthe toxicity of the groundwater togenerate a contaminant toxicitymap. Samples were exposed tothese environmentally relevant,bacterial biosensors to assess theiracute toxicity, and to assess towhat extent there was a toxicconstraint to site bioremediation.
The figures below are producedusing a geostatistical package toextrapolate borehole toxicity datato a contoured site toxicity map.The red areas have beendemonstrated by the biosensor tobe toxic, while the green areas arefree from contaminant toxicity.
Toxicity map of a contaminated site.
Total toxicity (i.e. areas with low intrinsic
bioremediation potential).
Anodic StrippingVoltammetryA simple and rapid on-siteelectrochemical sensor has beendeveloped for the detection ofheavy metals in soil and watersamples. The device utilisesDifferential Pulse Anodic StrippingVoltammetry (DPASV), coupledwith screen-printed electrodes(SPE). This approach was favouredfor reasons of cost, simplicity,speed (< 4 min) and sensitivity (µg l-1).
Following carbon ink selection andoptimisation of experimentalparameters, simultaneous analysisof Cd, Pb, and Cu was achieved.Calibration demonstrated linearityup to 200 µg l-1, and the followingdetection limits (in table). Thesensor was linked to a simple field-compatible sample extractionprocedure. 82 soil samples suppliedby consortium partners wereextracted and Pb, Cd and Cumeasured simultaneously. Theyielded correlation coefficientsafter comparison with ICP-OESdata are given in the table.Using a new low-cost portableelectrochemical analyser (PalmSensInstruments, Utrecht, NL), thesensor was successfully tested inthe field for the measurement ofcontaminated samples from ametal mining site and watertreatment plant for mine wastes.The addition of Hg and As to theassay was achieved using analternative gold (Au) SPE. Initialinvestigations yielded detectionlimits of 0.15 µg l-1 for Hg and 50 µg l-1 for As. Chemometric datatreatment will be performed to deconvolute overlapping strippingcurrents.
ASV field kit
3
WP2: field-based measurement tools
S.J. Setford, Cranfield Centre for Analytical Science, Cranfield University, Silsoe, MK45 4DT, UK
K. Killham, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU
400 600 800 1000 1200 1400 1600 1800 2000
200
400
600
800
1000
1200
05101520253035404550556065707580859095100
Total toxicityTotal toxicity
High toxicity
Low toxicity
Contaminant Detection Correlation
limits coefficients
[µµg l-1 ]
Pb 1.5 0.9728
Cd 10 0.9867
Cu 30 0.9537
PURE; Protection of groundwater resources at industrially contaminated sites
Supercritical fluidextraction + immunoassayA simple compact andtransportable field-basedsupercritical fluid extraction (SFE)apparatus has been developed forthe high efficiency extraction oforganic compounds from soilsamples. Extracts are subsequentlyanalysed in the field usingimmunoassay test kits. Real world samples were analysedas collected, without therequirement for a drying step. SFE
extracts were collected in methanoland diluted in aqueous buffer toengender compatibility betweenthe extracts and test kits. Thecombined SFE-immunoassay hasbeen optimised using synthetic andreal world samples containingpolyaromatic hydrocarbons (PAHs),BTEX compounds and chlorinatedhydrocarbons. The approachcorrelates well with the recognisedstandard soxhlet/GC-MS methodfor the analysis of real worldsamples.
Field-based evaluation of thecombined SFE-immunoassayprocedure as a screening methodfor PAH monitoring atcontaminated sites has provensuccessful. PAH recoveries of 60-130% (compared to soxhlet/GC-MS) were obtained. Theapproach holds obvious promisefor screening industrial sites forhydrocarbon contaminants and isconsiderably more environmentallyfriendly than competing high-efficiency methods.
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WP3: Site Characterisation and modelling
FASA: Fuzzy Areal SiteAssessment approach insite characterizationCharacterizing the nature and theextent of environmentalcontamination at a brownfield is afundamental part of any remedialinvestigation and corrective actionprogram. FASA has beendeveloped as an alternative to geo-statistics approaches. FASA’smethodology is not based onstatistical models/assumptionsmade on the underlyingdistribution of the contaminantacross the site. Furthermore, itdoes not use interpolation andcontouring algorithms to produce amap of the contaminantdistribution.
FASA generates a “rough”topology of the contaminantdistribution over a given site withaccuracy. The topology producedas such does not contain contoursindicating the concentration levelsof contaminants in the given soil
depth. Basically, FASA has twopowerful features: adaptive fuzzypartitioning and fuzzy arealassessment. These two featureshave been adapted from studiesconducted in the field of globaloptimization and further developedto deal with sparse data collectedfrom the site. FASA interprets theproblem of site characterization asa spatial classification problem andtreats the latter within a fuzzysetting. FASA is a partitioningmethod that divides the site
resulting in a finer tessellation aftereach re-partitioning. Each partitionis assessed using aggregate fuzzymeasures of concentration valuesof samples falling within thepartition. Using these measures,FASA provides non-statisticalestimates for the locations of non-contaminated blocks in the site.Partitions classified as non-contaminated are stored andreported. Thus, the area of the siteto be reinvestigated is reducedsignificantly.
1 The author is currently with Nanyang Technological University, School of Mechanical and Production Engineering, Systems and Engineering Management Division, 50 Nanyang Avenue, Singapore 639798
YED TEPE UN VERS TES
L. Ozdamar1, M. Demirhan, Yeditepe University, Dept. of Systems Engineering, Kayisdagi, Istanbul, Turkey (FASA)A. Battistelli, Aquater SpA (ENI group), Via Miralbello 53, 61047 San Lorenzo in Campo (PU), Italy (TMVOCBio code)
PURE; Protection of groundwater resources at industrially contaminated sites
In PURE, both hypothetical siteswith known results and real siteshave been utilized to demonstratethe performance of FASA.
FASA is developed with thefollowing major goals: – To reduce drilling and lab
analysis costs by optimising thesampling strategy in bothpreliminary and detailed phasesof site characterization. At thePURE test site, FASA has reducedthe total number of samplesrequired to characterize a site byapproximately 30%. During thepreliminary screening phase ofsparse sampling, FASA hasdecreased the area to besubjected to a more intensivesampling by nearly 50%.
– To carry out in-situ riskassessment of the site (reducingtransportation costs of movingsamples to labs and reducing thetime required for riskassessment) by utilizing a rapidand practical fuzzy logic based
spatial inference mechanism thatcan handle imprecise toxicitymeasurements collected by in-situ measurement technologiessuch as ASV and biosensors.
– To increase accuracy andminimize health hazards byproviding a tool with multiplecontrol so that hot-spots areidentified accurately. An accuracyexceeding 90% has beenachieved using less than half ofthe total number of samples.
Modelling of fate and transport (F&T)A quite general mathematicalformulation of aerobic andanaerobic biodegradation reactionsof organic compounds wasimplemented into the TMVOCBiomultiphase, non-isothermal,compositional numerical reservoirsimulator. The code can model thesimultaneous occurrence ofmultiple degradation processesinvolving several different organicsubstrates, electron acceptors and
nutrients. Reaction by-productscan also be simulated as well as thethermal effects of biodegradationin non-isothermal runs.Competitive, non-competitive,toxic and biomass growthinhibition effects can be accountedfor following the conventionalapproaches available in technicalliterature. The modelling ofbiodegradation reactions can beoptionally switched off.Verification and validation testswere successfully performed tocheck the proper implementationof mathematical and numericalformulations, as well as to controlthe actual capability of the code tomodel biodegradation processesobserved in laboratory experimentsand documented at onecontaminated site.
5
Benchmarking
A. Battistelli, Aquater SpA (ENI group), Via Miralbello 53, 61047 San Lorenzo in Campo (PU), Italy
M. Summersgill1, VHE Construction plc, Phoenix House, Hawthorn Park, Coal Road, Leeds, LS141PG, UK
The benchmarking has beenincluded to enlighten the coststhat are made with the currentstate of the art types of sitecharacterization and remediationtechniques.
This information demonstrates“where the money is going” andwhere possible savings can bemade. Besides, the information onthe current monitoring instrumentsand remedial techniques is
important as a comparison to theinnovative measuring strategiesand remedial techniques that havebeen developed within PURE.One part of the benchmarking wasthe collection of data about actualsite characterisation (SC) costs.Another part of the Benchmarkingactivities was to consider whetherin PURE developed innovativetechnologies could be translatedcommercially to field scaleapplications in the future.
A benchmarking study wasperformed specifically to reviewthe trends of market demand asthe project (and legislation)progressed. This was done tovalidate the potential cost savingsagainst ‘traditional’ technologies.The benchmarking exercise wasparticularly necessary to providesufficient data for the ABC tool;pan-European costs of allremediation technologies.
1 The author is currently with SenSe Associates, 91 King Street, MAIDSTONE ME14 1BG, UK
PURE; Protection of groundwater resources at industrially contaminated sites
The Site CharacterizationApproach for Recovery ofcontaminated industrial sites(SCAR) has been developed toenable the results of the PUREproject to be integrated andefficiently used by site owners totake the relevant decisions forsite management.
SCAR:– Contributes to the formulation of
a comprehensive and structuredoverview for the sites in thePURE project;
– Gives an overview of thedifferent steps of the sitecharacterization that could beapplied on different sites andcould be adapted according tothe needs of the site owner;
– Comprises an inventory ofexisting and historical sitedevelopment;
– Indicates possible siteremediation scenarios withassociated technical and financialuncertainties;
– Will enable the decision-makersto perform sensitivity analysisand test the robustness of theindividual site remediationalternatives in terms ofopportunity and risks.
Apart from the financial risks, like(internal) site information relatedto remediation alternatives andtheir financial aspects, also thehuman health, toxicological andenvironmental related risks areaddressed. These risks areimportant indicators for theinternal- (industrial plant) andexternal stakeholders (municipality,neighbourhood, water company).
The project results show whatinput, activity and criteria areneeded to obtain an output that
meets the expectations of both thedevelopers and end-users of theproject as much as possible. Theapproach is divided in three mainphases, phase 1 give a fastrelatively cheap impression of therisks, benefits and costs of theremediation of the contaminationinvolved, phase 2 give a moredetailed evaluation of the risks(technical, economical HSE andpolitical, benefits and costs. Inphase 3, field tests are carried outat the site and the site isremediated. Phase 1 and 2 arecarried out within SCAR.
The following PURE workpackageswere involved:– Sampling: Biosensors and Anodic
stripping voltammetry (ASV), WP 2;
– Mathematical calculations: FuzzyAreal Site Assessment (FASA),WP 3;
– Modelling fate and transport,WP 3;
– Assessment Benefit and Cost(ABC) tool, WP 1.
The anonymous site was alreadysampled, and the contaminationwas known by the site owner, sothis made it possible to validate theSCAR approach with the data ofthe ‘normal’ site characterizationalready performed.
Conclusions– The test with SCAR has shown
significant saving in costs andtime: ~40% and ~80%.
– The use of field-based sensors isvery applicable for quick scan.
– FASA yields very good resultscompared to existinginterpolation programs.
– ABC can be used as eye-openerfor innovative in-situ techniquesand as communication tool toenlighten decisions onremediation.
6
SCAR
Collection of soil samples
Perform soil analysis
Modelling fate and transport & Apply FASA
Apply ABC check
Phase 1
Repeat forPhase 2
SCAR exercise
PURE; Protection of groundwater resources at industrially contaminated sites
The industrial parties brought intheir specific sites withrepresentative problems. Theseproblems have been generalizedinto the categories: mixedpollution, low permeability andrecalcitrant compounds. The TREES WP’s have beenfocussed to tackle one or more ofthese problems with a specifictechnology.
7
TREESWP Technological approach Mixed Low permeable Recalcitrant
pollution soils compounds
4 Degradation of chlorinated X Xcompounds and heavy metal stabilisation
5 Electro bioremediation X6 Coupled degradation of X X
mixed contaminants7 Simultaneous remediation X
of saturated and unsaturated zones
8 Co-metabolism with Xmethane/butane oxidizer
WP4: Degradation of chlorinated compounds andheavy metal stabilisation
M. Camilli, E. D’Addario and R. Sisto, EniTecnologie, Environmental Technology Research Centre, Via Ramarini 32,
00016 Monterotondo, Roma, Italy
The technical and economicalfeasibility of a biological processfor the remediation of anindustrially polluted soil has beendemonstrated at lab and benchscale. The process consists in ananaerobic step, in whichautochthonous anaerobics such assulphate reducing bacteria (SRB),and Halorespiratory groups, arestimulated by a suitable C andelectron source (cheese whey),followed by an aerobic stepcarried out by facultativeheterotrophic microflora.
Dehalogenation of polychlorinatedpollutants such as DDT andchlorobenzenes, and thestabilisation of heavy metals (Hgand As) was accomplished duringthe anaerobic treatment of the soilas submerged and flooded slurry.The anaerobic DDT metabolism didnot cause the accumulation of itstoxic degradation products, such asDDD and DDE. Increase in chloride
concentration was consistent witha complete dechlorination ofaliphatic moiety of DDT. Thestabilisation of Hg and As asinsoluble sulphide wasdemonstrated by the conversion ofthe mobile fraction into the moststrongly bound one. Thedechlorination of pollutants andthe stabilisation of heavy metalsresulted in a significant decrease ofthe overall toxicity of the soil,measured by both MicrotoxTM testand the biosensor method (WP2).
The air sparging of the slurry afteranaerobiosis, resulted in a furtherdegradation of residual andpartially dechlorinatedcontaminants in mixedanaerobic/anoxic/aerobicconditions.Based on a preliminary economicalevaluation, this on-site process wascost effective (less than 80 €/tonof soil) in comparison to otheravailable remediation technologiesapplicable to chloroaromatics, suchas thermal desorption (80-210€/ton) or solvent extraction (100-200 €/ton).
Due to the duration of theanaerobic step, the techniqueappears best suitable to those caseswhere time is not a limiting factor.On the other hand, the anaerobicstep could also be considered aself-consistent process for thedetoxification of contaminatedsolids, such as soils, sediments orwastes.Bench scale experimental set-up.
PURE; Protection of groundwater resources at industrially contaminated sites
Electrobioremediation is anemerging technique, whichcombines classical electrokineticmethods with the possibilities forbioremediation in contaminatedsoil. For a successful application,knowledge is required on bothfields of science.
The electro osmotic flow can beused to move pollutants in low-permeable soils towards thecathode. This was shown in twodifferent soils for the compoundsPCE, toluene and chlorobenzene.In the case of chlorobenzene, thepore water concentration droppedfrom approximately 20 mg/L toless than 0.2 mg/L within 100days. Biodegradation ofchlorobenzene probably alsooccurred.The possibility to introduceelectron donors (volatile fattyacids, VFA) and acceptors (nitrate,sulphate) to stimulate in situbiodegradation by using the
electromigration process wasstudied in Dutch clay soil. VFA wastransported through the soil to theanode at a velocity of ca. 4 cm/h.The electron acceptors nitrate andsulphate were transported to theanode at a velocity of respectively3.7 cm/h and 2.1 cm/h. Theseexperiments show thatelectromigration can be used tofacilitate electron donor andacceptor transport in low-permeable soils where hydraulicmethods fail.
Also the role of humic acids duringelectroremediation processes wasinvestigated. A model compoundfor quinone moieties in humicacids, AQDS, as well as natural andsynthesised humic acids could bereduced in an electrokinetic cell.Consequently, it was demonstratedthat these reduced humicsubstances reduced hexachloro-ethane to tetrachloroethene (i.e.reductive dechlorination).
It can be concluded thatelectrobioremediation is atechnically feasible option to treatcontaminated low-permeable soils.The relevant processes areelectroosmosis, electromigrationand biodegradation. A suitablecombination of these processes canbe achieved to treat differentorganic pollutions.
8
WP5: Electrobioremediation
P. Middeldorp, TNO Environment, Energy and Process Innovation, P.O. Box 342, 7300 AH Apeldoorn,The Netherlands. A. Kappler and S. Haderlein, EAWAG, Postfach 611 CH 8600 Dübendorf, Switzerland
+ -
Anodecompartment
Cathodecompartment
Electroosmosis (H2O)
Ion migration
O2 H2
H+ OH-
+ -
Anodecompartment
Cathodecompartment
Electroosmosis (H2O)
Ion migration
O2 H2
H+ OH-
Experimental set up to study contaminant removal through electro-
osmosis.
0
5000
10000
15000
20000
25000
0 25 50 75 100 125 150 175 200Time (days)
Co
nc.
(µg
/L)
Port 1 (Cathode)Port 2Port 3Port 4Port 5 (Anode)
Chlorobenzene concentration in different parts of the column
during pore water flushing through electroosmosis.
PURE; Protection of groundwater resources at industrially contaminated sites
Industrially contaminated sitesoften contain different classes ofcontaminants (e.g. BTEX andhalogenated solvents) at the sametime. The feasibility of a potentialremediation approach based oncoupled biological and chemicaltransformation of such mixedcontaminants was investigated.
This approach relies on theprinciple that one class ofcontaminants (BTEX) is used aselectron donor by iron-reducingbacteria which in turn producereactive ferrous iron phases whichhave the potential of reductivedehalogenation of chlorinatedsolvents (electron acceptors).
The process of coupleddegradation of such mixedcontaminants was investigatedfrom three different directions.First, experiments were performedinvestigating the reactivity of Fe(II)bound to various naturally
occurring minerals with respect toabiotic (chemical) transformationof chlorinated pollutants (EAWAG). Reactive iron phases were obtainedby addition of soluble Fe(II) tosuspensions of different mineralsunder anoxic conditions.
Second, the degradation of BTEXby iron-reducing bacteria and thedependence of their activity onenvironmental factors were studied(UKon).
Finally, BTEX degradation by iron-reducing bacteria and abiotictransformation of chlorinatedpollutants by reactive biogenic ironphases were coupled in batch andcolumn experiments (EAWAG andUKon).
In the work the proof of principlehas been demonstrated that canform the basis of an innovative in-situ technique.
9
WP6: Coupled degradation of mixed contaminants
K.L. Straub and B. Schink, University of Konstanz Fachbereich Biologie, Postfach 5560 (M654) D-78457Konstanz, Germany, A. Kappler, T. Hofstetter and S. Haderlein, EAWAG, Postfach 611 CH 8600 Dübendorf, Switzerland
HCOO-
HCCl3
HCOO-CCl4
CCl3
CCl3-
CO
CCl3-
HCOO-
CO
Chloroform Carbon monoxideFormate
Carbon tetrachloride
Cl
ClClH
Cl
ClClCl
Pollutantoxidized
Pollutantreduced
structural or surfacebound species
Fe(II)
Fe(III)
Fe(II) adsorption
organic material
microbial reduction
CO2
Toluene
CH3
Schematic representation of the coupled
microbial Fe(III) mineral reduction and
reductive pollutant transformation illustrated
by the reduction of CCl4 to CHCl3, carbon
monoxide and formate and concomitant
oxidation of toluene to carbon dioxide.
Indications for reaction pathways obtained in this study. The product formation cannot be
rationalized in terms of free intermediates in solution.
PURE; Protection of groundwater resources at industrially contaminated sites
The further development of thetwo remediation concepts,thermally enhanced soil vapourextraction (TSVE) and co-solventflushing (CSF), was directly linkedto industrially contaminated sitesowned by the project partners.
Samples from two PURE sites wereanalysed and contained differentportions of aromatic hydrocarbons.The remediation fluid required forCSF was chosen based on theenhancement of the aqueoussolubility of the contaminants andthe reduction of the interfacialtension between the aqueous andnon-aqueous phase. During the laboratory flumeexperiments concerning CSF, theeffect of the vertical upward flowvelocity of the alcohol mixture onthe stability of the flow regime wasinvestigated. Additionally, a CSFremediation experiment wascarried out in the laboratory flume.By flushing two pore volumes ofthe alcohol-water mixture throughthe soil from one PURE site, morethan 90% of the initialcontamination was removed.A novel approach tosimultaneously remediate bothsaturated and unsaturated zoneswas investigated in laboratoryflume experiments. By injectingsteam into the saturated zone
(SubTSVE), an effective heating ofboth zones was achieved resultingin excellent contaminant massremoval rates. Since there was nopossibility to conduct a pilotremediation trial at one of thePURE sites, both technologies weretested in a large VEGAS container(70 m3) packed with soil from onePURE site contaminated by thesite-specific hydrocarbon mixture.During the SubTSVE remediationexperiment a steam-air mixturewas injected into the saturatedzone by two injection wells (I1, I2)to prevent a mobilisation of thecontaminants. Soil vapour wasextracted by four wells (E1 – E4).During two days of operation acomplete, controllable and saferemoval of the contaminationlocated in the saturated andunsaturated zone (hatched area)was achieved. Experiments in thelarge VEGAS container proved thegeneral applicability of TSVE andSubTSVE for conditions of thesubsurface similar to those at thetwo PURE sites. On request of aclient from industry the SubTSVEtechnology was successfullyapplied at a small sitecontaminated by DNAPL (CHC).During the CSF remediationexperiment the alcohol mixturewas injected via a horizontal well inthe middle on the bottom of the
large VEGAS container. Two multi-level vertical wells were used forthe extraction of the alcohol-mixture loaded with contaminants.After two days of alcohol flushingthe the alcohol mixture flushed thecontaminant source zone locatedclose to the water level thoroughly.This is in accordance with results ofthe accompanying numericalsimulation. Approx. 88% of theinitial contaminant mass wereextracted after a four day injectionperiod of the alcohol mixture. Afteradditional ten days of waterinjection the used isopropanol wascompletely recovered and approx.90% of the initial contaminantmass were removed. Additionally, asafe and hydraulically controllableremediation procedure for DNAPLcontaminated sites was developed.For the removal of chlorinatedhydrocarbons (TCE and PCE), aremediation fluid was developedand the critical upward DarcyVelocity needed to prevent anuncontrolled downwardmobilisation of the DNAPL wasdetermined in various grainedsands. The applicability of CSF forsites contaminated with TCE wasproved by a remediation experi-ment carried out in a large flume,which resulted in a contaminantmass removal of approx. 90%.
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WP7: Site simultaneous remediation of saturated andunsaturated zone
H-P. Koschitzky, O. Trötschler, K. Weber, Vegas Versuchseinrichung zur Grundwasser – und
Altlastensanierung (Research facility for subsurface remediation), University of Stuttgart, Germany
Heat propagation
during remediation
experiment SubTSVE.
Contaminant con-
centration in the
extracted fluids and
cumulative conta-
minant mass remo-
val over time of
injected alcohol
mixture.
PURE; Protection of groundwater resources at industrially contaminated sites
The possibility to biodegradechlorinated aliphatic hydro-carbons (CAHs, or chlorinatedsolvents) by aerobic co-metabolism is well known butseldom applied in-situ. Thistechnology proved to be able todegrade several CAHs with 1, 2, 3and in some cases even 4 chlorineatoms.
The cometabolic process consists inthe fortuitous transformation of anorganic compound (the CAH) byan enzyme produced for themetabolization of a primarysubstrate; therefore, the aerobiccometabolic degradation of CAHsrequires the supply of a suitablegrowth substrate, which can beeither a light aliphatic hydrocarbon(such as methane, propane orbutane), or an aromatichydrocarbon (such as phenol ortoluene) or ammonia. Aerobiccometabolism can potentially beimplemented in both in-situ andon-site applications. In the in-situ
applications the primary substrateand oxygen as electron acceptor,are introduced into thegroundwater via injection wells.Different aspects of thecometabolic biodegradation ofseveral chlorinated solvents bybiomasses utilizing methane,butane and propane as primarysubstrate were investigated. Moreprecisely, the cometabolicdegradation of vinylchloride (VC),cis- and trans-1,2-dichloroethylene(c-DCE and t-DCE), trichloro-ethylene (TCE), 1,1,2-trichloro-ethane (1,1,2-TCA), 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA)and chloroform (CF) was studied inslurry batch microcosms, and thecometabolic degradation of CF wasstudied in a 30 m3 macrocosmoperated both as a flow reactorand as a batch reactor. In addition,a pilot-scale in-situ process hasbeen designed in detail andsimulated by means of a model ofgroundwater flow withcometabolic degradation kinetic.
As of today, the technology needsfurther improvement for a full-scale application on the market.The main hurdles are:– In some cases, long times are
required for the adaptation ofthe indigenous biomass to thechlorinated solvents andconsequently for the onset of thebiodegradation process.
– If bioaugmentation (= intro-duction in the site of selectedbacterial strains or consortia,deriving from the indigenous sitebiomass or from an exogenoussource) is implemented, notmuch knowledge is available onthe mechanisms of dispersion ofthe inoculum in the subsurfaceand on consequent degree of“colonization” of the aquifer.
– Due to the risk of excessivebiomass growth near the point ofinjection of the growth substrate,it is necessary to implement tech-niques aimed at restricting bio-mass growth (pulsed injection ofsubstrate, introduction of H2O2).
11
WP8: Co-metabolism with methane butane oxidizers
A. Farneti, Aquater S.p.A. (ENI-Group), Via Miralbello 53, 61047 San Lorenzo in Campo (PU), Italy.M.Camilli, EniTecnologie, Via Ramarini 32, 00016 Monterotondo, Roma, Italy. A. Bernardi, PolimeriEuropa, Via G. Fauser 4, 28100 Novara, Italy
Contaminatedinfluent
Treatedeffluent
Extraction well
Bioactive zone
Mixing unitInjection well
Nutrients +pH control
Electron donor(primary substratum)
Electron acceptor(air)
Injection
extraction
well system
PURE; Protection of groundwater resources at industrially contaminated sites
The roots of the PURE project layin the NICOLE network (Networkof industrially contaminated land;www.nicole.org) that pointed outcost-effectiveness and eco-efficiency as the fundaments of asound approach to siteremediation.
At the start of the 5th FP some ofthe industrial partners of NICOLEtook the challenge to worktogether with service providers andresearch centres of outstandingskill in the field, to undertake aproject aiming to exploreinnovative solutions for cost-effective and ecoefficientcharacterization and remediation ofmulti-polluted industrial sites. Thefollowing criteria for assessing the
success of the research wereagreed upon:– Characterization and remediation
are part of the same process andthere is need for improving bothaspects.
– Costs and environmental benefitsare equally essential for theevaluation of a new technology.
– A R&D project is of interest toindustry if it addresses realproblems and if developedsolutions are actual applicable.
Several lessons can be learned fromthe project. – Dealing with contaminated soil
and groundwater, the impact oflaws and bureaucracy constraintsshould not be underestimated.Especially in some countries,
problems arise from such type ofconstraints in having access tosoil and groundwater samplesand data, as well as to carry outfield test.
– When addressing many technicalaspects in parallel, the timeneeded to effectively carry outthe “integration and convergingideas” is an important part of thetime spent for the technicalactivities and should be properlyestimated and included in theproject.
– The benchmarking exercise,although it resulted in aremarkable set of data, stillconfirmed that it is difficult, foran array of reason, to definereference costs for Europe.
12
Overall
WP 9: Project management, integration and convergingideas
P. Cortesi, Polimeri Europa SpA, Piazza Boldrini 1, 20097 San Donato Milanese (MI), Italy
(Coordinator of the project)
TNO Environment, Energy and Process Innovation
Polimeri Europa SpA (Industry/site owner) Italy
(Coordinator PURE)
TNO (Research centre) The Netherlands
(Scientific coordinator PURE)
EniTecnology (Corporate research centre) Italy
Aquater (Service provider) Italy
University of Konstanz (University ) Germany
University of Stuttgart (VEGAS) (University) Germany
FORD (Industry/site owner) Germany
ICI Paints (Industry/site owner) Germany
AKZO-Nobel (Industry/site owner) The Netherlands
EAWAG (Research Centre) Switzerland
University of Cranfield (University) United Kingdom
VHE (Service provider) United Kingdom
Yeditepe University (University) Turkey
Consortium
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