Lecture 14Miscellaneous topicsin remediation:New remediation technologies; technical impracticability; andgasoline additivNew remediation technologiesPhytoremediationPhytoremediationExplosives rhizosphere bioremediationPoplar trees for phytoextractionWild mustard plant for metals phytoextractionElectrokinetic remediationLasagna processThermal treatment (enhanced SVE)Thermal treatment of PCBs in soilAfter thermal treatmentFracturing of low-conductivity geologic mediaCirculating wellsIn-well air strippingDensity-driven convectionDual-phase vapor extractionDual-phase extraction (DPE) wellDual-phase extractionTwo-phase extractionChemical oxidationChemical oxidationOxidizing agents: PeroxideOxidizing agents: PeroxideField trial of Fenton’s ReagentOxidizing agents: PermanganateOxidizer comparisonOxidizer comparisonOxidizing agents: OzoneSITE: Superfund Innovative Technology Evaluation ProgramFederal Remediation Technologies RoundtableTechDirect NewsletterCost estimating resourcesTechnical impracticabilityEPA DirectiveTI RequirementsEvaluation of restoration potentialREILLY TAR & CHEMICAL SITEGasoline AdditivesGasoline OxygenatesGrowth in use of MTBEUse of MTBEMethyl tertiary Butyl Ether - MTBEMTBE PropertiesMTBE PropertiesPrevalence of MTBEExample MTBE SiteLecture 14Miscellaneous topicsin remediation:New remediation technologies; technical impracticability; andgasoline additivesNew remediation technologiesPhytoremediationElectro-kinetic remediationBedrock fracturingCirculating wells/in-well treatmentIn-situ oxidationDual-phase vapor extractionPhytoremediationPlant MetabolismPlant UptakeRoot AbsorbtionContaminantsBiodegradationin theRhizospherePhytoremediationPhytotransformation – uptake from soil and ground water, transformation within the plantRhizosphere bioremediation – augmentation of bacterial processes in plant root zone Phytostabilization – hydraulic control by pumping action of trees, physical soil stabilization by rootsPhytoextraction – use of metal-accumulating plants to extract metals from soils and concentrate them in roots, stems, or leavesRhizofiltration – plant roots acting to sorb, concentrate, or precipitate metalsExplosives rhizosphere bioremediationAcccessedMarch 28, 2004.Artificial wetland constructed in gravel base reduced total explosives (TNT, RDX, HMX) from 9200 to 50 ppb.Source: Defense Environmental Restoration Program, undated. “The Role of Technology.” http://www.dtic.mil/envirodod/derpreport96/vol1/technol.htmlPoplar trees for phytoextractionSource: Pincus, M., 2003. Greener Cleaners, Using Phytoremediation to Remediate Environmental Toxins. Studentpaper for MIT Course 1.34.Courtesy of Melanie Pincus. Used with permission.Wild mustard plant for metals phytoextractionSource: Salt, David E., undated. Molecular Physiology of Heavy Metal Accumulation and Tolerance in Plants. Horticulture and LandscapeArchitecture, Purdue University, West Lafayette, Indiana. http://www.hort.purdue.edu/hort/people/faculty/salt.shtml. Accessed March 28, 2004.Wild mustard plant willhyperaccumulate nickel,reaching shoot concentrations as high as 1.2%.Persans, M. W., K. Nieman, and D. E. Salt, 2001. Functional activity and role of cation-efflux family members in Ni hyperaccumulation in Thlaspigoesingense. PNAS. Vol. 98, No. 17, Pg. 9995-10000. August 14, 2001.Persans, M. W., K. Nieman, and D. E. Salt, 2001. Functional activity and role of cation-efflux family members in Ni hyperaccumulation in Thlaspi goesingense. PNAS. Vol. 98, No. 17, Pg. 9995-10000. August 14, 2001.The ability of Thlaspi goesingense to hyperaccumulate Ni seems to be governed in part by enhanced accumulation of Ni within leaf vacuoles. We have characterized genes from T. goesingense encoding putative vacuolar metal ion transport proteins, termed metal tolerance proteins (TgMTPs). These proteins contain all of the features of cation-efflux family members, and evidence indicates they are derived from a single genomic sequence (TgMTP1) that gives rise to an unspliced (TgMTP1t1) and a spliced (TgMTP1t2) transcript. Heterologous expression of these transcripts in yeast lacking the TgMTP1 orthologues COT1 and ZRC1 complements the metal sensitivity of these yeast strains, suggesting that TgMTP1s are able to transport metal ions into the yeast vacuole in a manner similar to COT1 and ZRC1. The unspliced and spliced TgMTP1 variants differ within a histidine-rich putative metal-binding domain, and these sequence differences are reflected as alterations in the metal specificities of these metal ion transporters. When expressed in yeast, TgMTP1t1 confers the highest level of tolerance to Cd, Co, and Zn, whereas TgMTP1t2 confers the highest tolerance to Ni. TgMTP1 transcripts are highly expressed in T. goesingense compared with orthologues in the nonaccumulators Arabidopsis thaliana, Thlaspi arvense, and Brassica juncea. We propose that the high-level expression of TgMTP1 in T. goesingense accounts for the enhanced ability of this hyperaccumulator to accumulate metal ions within shoot vacuoles.Courtesy of David Salt. Used with permission.Electrokinetic remediationSource: Van Deuren, J., T. Lloyd, S. Chhetry, R. Liou, and J. Peck, 2002. Remediation Technologies Screening Matrix and Reference Guide, 4th Edition. Federal RemediationTechnologies Roundtable.Lasagna processElectro-osmosis moves contaminant in low permeability environmentsThe Lasagna™ process works by using buried electrodes to move water through the soil. Applied current drives the water an inch a day from a positive to a negative electrode. The water picks up contaminants and moves them through treatment zones where they are trapped or degraded. http://www.em.doe.gov/emprog/spr009.htmlThermal treatment (enhanced SVE)See image in Bader, C. D., 1997. In-Situ Soil Remediation. Remediation Management. Vol. 3, No. 2, Pg. 22. Second Quarter 1997.Thermal treatment of PCBs in soilSee image in Bader, C. D., 1997. In-Situ Soil Remediation. Remediation Management. Vol. 3, No. 2, Pg. 22. Second Quarter 1997.After thermal treatmentSee image in Bader, C. D., 1997. In-Situ Soil Remediation. Remediation Management. Vol. 3, No. 2, Pg. 22. Second Quarter 1997.Fracturing of low-conductivity geologic mediaPneumatic PressureSource2-ft Fracture IntervalCirculating wellsSource: Van Deuren, J., T. Lloyd, S. Chhetry, R. Liou, and J. Peck, 2002. Remediation Technologies Screening Matrix and Reference Guide, 4th Edition. Federal RemediationTechnologies