Soil contamination and remediation. Remediation Site characterization

Transcription

1 Soil contamination and remediation Remediation Site characterization

2 Site characterization Questions to be answered by site characterization Nature and extent of contamination where is it? What is future migration and control where is it going? What are receptors and their risk what harm will it do? What are technical options for remediation how do we fix it?

3 Data needed from site characterization 1. Contaminant sources research history as well as collect samples 2. Extent of contamination 3. Hydrogeologic setting 4. Restoration potential

4 Stages of investigation Stage 1 scoping study Is there a problem? How bad is it? Stage 2 prepare field study plan Includes sampling and analysis, health and safety Stage 3 conduct on-site sampling and analysis Stage 4 interpretation, assessment, modeling Stage 5 design remedial action

5 Basic data about a site Topographic maps (in CR Základní mapa ČR ) scale 1: Understand geographic setting, topography, nearby water bodies Background geologic data - Ground-water maps - Geological maps - ČGS Czech Geological Survey - Geological works database (Geofond) - eearth database (some european countries)

6 Geological maps (in CR issued by CGS, whole area of CR accessible online

7 Basic information about contamination source Understand site use and history Where were chemicals handled or disposed? What site structures or activities are potential sources? What chemicals are and were handled?

8 Health and Safety Equipment Labor Productivity Equipment Productivity Moon suit 37 % 50 % SCUBA; 48 % 60 % facial mask Respirator; 55 % 75 % Tyvec suit Normal work 82 % 100 % protection No personal protection equip. 100 % 100% Source: Rast, R. R., Environmental Remediation Estimating Methods. R.S. Means Company, Inc., Kingston, Massachusetts.

9 Field vapor analyzers OVA Flame Ionization Detector aliphatics, aromatics, haloethanes, halomethanes

10 Geophysical methods Method Electrical resistivity tomography Electromagnetic induction Seismic refraction Seismic reflection Radar (GPR) Magnetometry Gravity survey Objects Conductive or nonconductive contaminants, stratigraphy -//- + metal objects Stratigraphy (top of bedrock); depth to ground water High resolution mapping of top of bedrock Buried objects (plastic and metal); stratigraphy; depth to ground water Buried metal objects Overburden thickness; landfill boundaries

11 Soil vapor monitoring

12 Soil vapor monitoring Contaminants: Chlorinated hydrocarbons CFC Aromatic hydrocarbons Methane Ketones (e.g. aceton)

13 Examples of soil gas contamination distribution

14 Drilling Composition of layers and stratification Hydrogeologic conditions - ground water level - hydraulic properties Sampling of soil and water - quantification of contaminants - where is the contamination plume center

15 Direct push - Geoprobe

16 Classical drilling Hollow stem auger Direct rotary

17 The drill stem and sampler barrel are vibrated vertically at frequencies between about 50 and 180 Hz such that the sampler barrel normally advances by slicing through the soil. Sonic drilling

18 Split spoon sampler Undisturbed samples for: chemical analysis of soil physical properties of soil Experiment for breakthrough curves -> transport parameters

19 Issues in field sampling Safety Cross contamination Artifacts QA/QC Sampling Handling

20 Potential Artifacts Substance Methylene chloride, MEK, chloroform, carbon tet. Phthalates chloroform Acetone, isopropyl alcohol, hexane Barium, high ph methyl chloride Methyl Ethyl Ketone (MEK) Artifact source Laboratory solvents Plasticizers in tubing Domestic water Field decontaminants Drilling fluid, grout Natural chemical Duct Tape (silver tape) Source: Morrison, R. D., Environmental Forensics: Principles and Applications. CRC Press, Boca Raton, Florida.

21 Monitoring well

22 Monitoring well

23 Sand filter Sampling unit Plug Multi level sampling of water Less costly than several monitoring wells Exclusion of the influence horizontal heterogeneity Water pressure measurement in several depths

24 Crossection

25 Groundwater sampling Submersible pump Peristaltic pump Bailer

26 Analytical chemistry - Chromatography Gas chromatography, GC Separation in capillary tube or column Different substances have different retardation Detectors : TCD Thermal Conductivity Detector (general purpose) FID Flame ionization (hydrocarbons) ECD- Electron capture detector (pesticides) Separační metody

27 Analytical chemistry - Chromatography High performance chromatography, HPLC Separation in a column Schéma HPLC Detectors: UV / VIS detector fluorescence detector DAD photodiode array MS mass spectrometry Separační metody

28 Analytical chemistry - Chromatography Result is a. CHROMATOGRAM peaks area is directly related to the concentration of a substance Absolute values of concentration are obtained from calibration curve Separační metody

29 Laboratory analysis (cost in CZK) Zdroj: Monitoring s.r.o. Analytická laboratoř Metals: each ,- group 1500,- Metodický pokyn MŽP ČR 8/96 (Zemina) (As,Ba,Be,Cd,Co,Cr,Cr6+,Cu,Hg,Mo,Ni,Pb,Sb,Sn,V,Zn) Těkavé látky TOL: chlorované ethylény 900,- vyhláška č. 252/2004 Sb 1200,- (1,2-dichloretan, VC, TCE, PCE,chloroform, bromoform, bromdichlormetan, dibromchlormetan, benzen, toluen, etylbenzen, xyleny) Polychlorované bifenyly (PCB): 1500,- Pesticidy - organochlorové (OCP): 900,- - triazinové (TP): (simazin,atrazin,propazin,terbutylazin) 1150,- Polycyklické aromatické uhlovodíky (PAU) 1300,- Vyhláška 383/2001Sb. odpady (PAU 15)

30 References MIT Open courseware Environmental-Engineering/1-34Spring2004/LectureNotes/index.htm Sharma, H.D., Reddy, K.R. Geoenvironmental engineering, Wiley, 2004 Domenico, P.A. a Schwarz, F.A. Physical and Chemical Hydrogeology, 1990 EMOMONITOR Chrudim, Využití biodegradačních metod při sanacích znečištění,