Treatment Technologies

Treatment TechnologiesTreatment Technologies

ENVM 644: New Technologies in Environmental Management

Dr. Robert Beauchamp

PHYSICAL TREATMENTS PHYSICAL TREATMENTS

INCINERATION– DESTROYS ORGANIC COMPOUND

– CONVERTS LIQUIDS TO SOLIDS & REDUCES VOLUME.

– 900 - 1500 DEGREES C

– EXAMPLE: ROTARY KILN, LIQUID INJECTION

THERMAL DESPORPTION– VOLATIZES VOC's.

– 300-600 DEG. C.

PHYSICAL TREATMENTS (cont)PHYSICAL TREATMENTS (cont)

PYROLYSIS – CONVERTS VOC's TO COMBUSTIBLE, GAS, CHARCOAL, LIQUIDS

AND ASH.

– 500-800 DEG. C.

VITRIFICATION – HIGH TEMPERATURE ELECTRODES MELT THE WASTE.

– IN-SITU OR EX-SITU.

– GASES ARE COLLECTED BY A HOOD FOR TREATMENT.

– 4,000 VOLTS REQUIRED TO REACH 3,600 DEG. C.

– NEED SUFFICIENT GLASS FORMING MATERIAL, DEEP WATER TABLE.

IN-SITU PHYSICAL TREATMENTS (SOILS)IN-SITU PHYSICAL TREATMENTS (SOILS)

SOIL FLUSHING:– REMOVING SOIL CONTAMINANTS ORGANIC/INORGANIC) USING

WATER FOR TREATMENT.

SOIL WASHING:– SIMILAR TREATMENT USING: WATER, ACIDIC SOLUTIONS, &

SURFACTANTS

SOLIDIFICATION/STABILIZATION– POZZOLAN - PORTLAND SYSTEMS (PHYSICAL ENTRAPMENT.

SOILS CONTAINING METALS, PCB'S, OIL SLUDGES, VINYL CHLORIDE, RESINS,ASBESTOS, SULFIDES, ETC.)

– POZZOLANS INCLUDE: FLY ASH,PUMICE, LIME KILN DUST.

THERMOPLASTIC TREATMENT– ASPHALT OR POLYETHYLENE - BINDS THE WASTE (SLUDGES,

PAINT, RADIOACTIVE MATERIALS, METALS & ORGANICS)

THERMAL ENHANCEMENTSTHERMAL ENHANCEMENTS

FOCUS:– IN-SITU CONTAMINANT DESTRUCTION – ENHANCE REMOVAL

 CONSIDERATIONS: – REMOVE VAPOR PHASE– REMOVE FREE PRODUCT– IN-SITU DESTRUCTION– DECREASE SOLUBILITY– PLAN ON VARIATION IN SOIL PERMEABILITY. – LOW PERMEABLE STRATA CAN BE HEATED QUICKLY.– HEATING IMPROVES REMEDIATION FOR MOST TECHNOLOGIES.

MECHANISMS FOR IN-SITU THERMAL REMEDIATIONMECHANISMS FOR IN-SITU THERMAL REMEDIATION

ALL PHYSICAL PROPERTIES ARE TEMPERATURE DEPENDENT.

AS TEMP. INCREASES, SO DOES:– VISCOSITY– VAPOR PRESUURE– SOLUBILITY– DIFFUSION RATE– DENSITY DECREASES

EXAMPLES OF TEMP. INCREASES: – LIQUIDS START MOVING– SEMI AND NON-VOLATILES HAVE HIGH VISCOSITIES.– INCREASE VAPOR PRESSURE OF NON-VOLATILES– ENHANCE BIDEGRADATION MICROBIAL SURVIVAL @ 1000C

MECHANISMS FOR IN-SITU THERMAL REMEDIATIONMECHANISMS FOR IN-SITU THERMAL REMEDIATION

ALL PHYSICAL PROPERTIES ARE TEMPERATURE DEPENDENT.

AS TEMP. INCREASES, SO DOES:– VISCOSITY– VAPOR PRESUURE– SOLUBILITY– DIFFUSION RATE– DENSITY DECREASES

EXAMPLES OF TEMP. INCREASES: – LIQUIDS START MOVING– SEMI AND NON-VOLATILES HAVE HIGH VISCOSITIES.– INCREASE VAPOR PRESSURE OF NON-VOLATILES– ENHANCE BIDEGRADATION MICROBIAL SURVIVAL @ 1000C

UNDERGROUND STRIPPINGUNDERGROUND STRIPPING ( (INCLUDES STEAM & ELECTRIC)INCLUDES STEAM & ELECTRIC)

WORKS WELL BELOW GW.

STEP 1: CUT DNAPL FROM PLUME

STEP 2: IMPLEMENT HEATING (STEAM & ELECTRIC ARE PORTABLE)– NOTE: IF IN A HURRY, CONSIDER THERMAL METHODS.

THERMAL REQUIREMENTS:– SET UP THE HEAT.

– CAN'T LEAVE ANY COLD AREAS.

– NEED RELIABLE EXPERIENCE.

– ENERGY FLUX = 1 YD3 NEEDS 100 KWHR = 1000 C. HIGH ENERGY

– NEED CONDENSER

– NEED TO TREAT WATER

– EST. ENERGY COST = $1.00/YD3

UNDERGROUND STRIPPINGUNDERGROUND STRIPPING ( (INCLUDES STEAM & ELECTRIC)INCLUDES STEAM & ELECTRIC)

ADVANTAGES:– ELECTRIC OK FOR SHALLOW SITES.

– STEAM GOOD FOR DEEP SITES

– OK FOR HIGH CONCENTRATION AND VARIOUS CONTAMINANT TYPES.

– COST EFFECTIVE IN REMOVING SOURCE AREA.

– DEPTH RESTRICTION - 140 FEET MAY GO DEEPER WITH STEAM.

NOTE: NOT TRIED IN FRACTURED ROCK

UNDERGROUND STRIPPINGUNDERGROUND STRIPPING

STRATIGRAPHY & HYDROLOGY PERMITTING, STEAM CAN DRIVE CONTAMINANT UPWARD.

EXAMPLE: STEAM HEATING SOIL (CLAY) & WATER WITH A CONTAMINANT

RESULTS:– INCREASES PRESSURE & CONTAMINANT CAN BE DRIVEN INTO AN

AQUITARD AT LOWER PRESSURES.

– ELECTRICAL RESISTANCE TOMOGRAPHY CAN IDENTIFY SPREAD OF STEAM.

– STEAM CAN TRACE FRACTURES IN ROCK.

– COLD POCKETS WILL LIKELY CONTAIN CONTAMINANT.

NOTE: THE GROUND IS A TERRIFIC SINK FOR HEAT. NEED ENOUGH HEAT.

UNDERGROUND STRIPPINGUNDERGROUND STRIPPING

STRATIGRAPHY & HYDROLOGY PERMITTING, STEAM CAN DRIVE CONTAMINANT UPWARD.

EXAMPLE: STEAM HEATING SOIL (CLAY) & WATER WITH A CONTAMINANT

RESULTS:– INCREASES PRESSURE & CONTAMINANT CAN BE DRIVEN INTO AN

AQUITARD AT LOWER PRESSURES.

– ELECTRICAL RESISTANCE TOMOGRAPHY CAN IDENTIFY SPREAD OF STEAM.

– STEAM CAN TRACE FRACTURES IN ROCK.

– COLD POCKETS WILL LIKELY CONTAIN CONTAMINANT.

NOTE: THE GROUND IS A TERRIFIC SINK FOR HEAT. NEED ENOUGH HEAT.

IN-SITU DNAPL REMEDIATION USING SIX PHASE HEATINGIN-SITU DNAPL REMEDIATION USING SIX PHASE HEATING

ELECTRODES PLACED IN GROUND

CURRENT IS PULSED BETWEEN ELECTRODES. 150 - 300 VOLTS AT DEPTH.

CAN HEAT EVENLY USING INTERLOCKING ARRAYS.

CAN BE USED WITH STEAM.

CAN PREVENT DNAPL MOBILITY BY HEATING BELOW DNAPL.

ADVANTAGES:– SOIL HETEROGENEITY IS NOT A PROBLEM.– HEATING MAKES CONTAMINANT LESS VISCOUS.– 111 TCE WILL DEGRADE QUICKLY.– DNAPL HEATS QUICKLY, PRODUCES CHLORIDE IONS WHICH

CONTRIBUTES TO HEATING FASTER.

IN-SITU THERMAL DESORPTIONIN-SITU THERMAL DESORPTIONUSING THERMAL CONDUCTOR & VACUUMUSING THERMAL CONDUCTOR & VACUUM

A QUIET INTRUSIVE TECHNOLOGY

REQUIRES ELECTRICAL POWERED ELECTRODE AND HEATED VACUUM WELLS.

REQUIRED TEMPERATURES - 15000 F AT THE WELLS, 8000 F BETWEEN WELLS.

THERMOCOUPLES INSTALLED TO MONITOR PROGRESS.

DIRECT PUSH WELLS CAN BE INSTALLED 1 PER MINUTE.

RADIO FREQUENCY HEATINGRADIO FREQUENCY HEATING

ELECTROMAGNETIC RADIATION

ANTENNAS PLACED IN GROUND & DIRECTED TOWARD CONTAMINANT.

HIGH HEAT > 1000 C; LOW HEAT < 1000 C

NEED SVE SYSTEM/AIR SPARGING INCREASES BIODEGRADATION 30 - 400 BEST.

SYSTEM IS MOBILE--TRAILER

ADVANTAGES:– GOOD FOR HIGH CONCENTRATION &VARIOUS CONTAMINANT TYPES.– COST EFFECTIVE– NO DEPTH RESTRICTION

NOTE: STEAM BEST FOR DEEP SITES AND RF NOT TRIED IN FRACTURED ROCK.

IN-SITU CHEMICAL OXIDATION IN-SITU CHEMICAL OXIDATION

DELIVERY OF OXIDANTS, i.e.– K PERMANGANATE– Na PERMANGANATE

Ph IS IMPORTANT, = 3 – 12

Ph DROPS WITH OXIDANT DELIVERY TO SUBSURFACE

AS TEMP. INCREASES, RATE INCREASES.

IN-SITU CHEMICAL OXIDATION (cont) IN-SITU CHEMICAL OXIDATION (cont)

ADVANTAGES:– FACILITATES OTHER METHODS– PROMOTES RAPID CLEANUP– ENHANCES BIOREMEDIATION

DISADVANTAGES:– DIFFICULT TO DELIVER – HIGH EFFICIENCY NOT A GIVEN– CAN CHANGE SOIL PERMEABILITY – METAL MOBILITY MAY OCCUR

NOTE: MUST MATCH OXIDANT WITH DELIVERY SYSTEM

GROUNDWATER CIRCULATION WELLS GROUNDWATER CIRCULATION WELLS

WATER IS RE-CIRCULATED DOWNWARD & CONTAMINANTS EXTRACTED BY AIR INTO A TREATMENT SYSTEM AS GAS.

WELLS ARE SCREENED AT TOP & BOTTOM OF CONTAMINATION.

WELL LOCATION SHOULD BE TANGENT TO GW FLOW.

AQUIFER ANISTROPHY 3 – 10 Kh / Kv

DISTANCE BETWEEN SCREENS DEFINES ZONE OF INFLUENCE

DISADVANTAGES:– MAY MOBILIZE CONTAMINANTS – DON'T LOWER WATER TABLE– LOW PERMEABILITY LIMITS EFFECTIVESS OF WELLS.

PERMEABLE WALLS/ BARRIERS PERMEABLE WALLS/ BARRIERS

USE OF ELEMENTAL IRON:– REDUCE Cr 3 to Cr 6

– ZERO VALENCE IRON NEEDED FOR TREATING CHLORINATED SOLVENTS.

USE OF LIMESTONE:– RAISE Ph TO CAUSE SORPTION/PRECIPITATION OF LEAD.

– BARRIER NEEDS TO BE MORE PERMEABLE THAN FORMATION

– NEEDS TO BE REPLACED-10 YEARS

PERMEABLE WALLS/ BARRIERS (cont)PERMEABLE WALLS/ BARRIERS (cont)

ADVANTAGES:– SYSTEMS EASY TO MONITOR

– CAN BE DEEP - 120 FEET

– COST EFFECTIVE

– ENHANCES BIODEGRADATION

– NO O & M COSTS

DISADVANTAGES:– EMPLACING TECHNOLOGY CAN BE CHALLENGING

– NOT APPLICABLE TO FUELS & BTEX.

– BARRIER NEEDS TO BE MORE PERMEABLE THAN SUBSURFACE

IN-SITU FLUSHING OF NAPL SOURCE ZONESIN-SITU FLUSHING OF NAPL SOURCE ZONES

FOR NAPL's AND DNAPL's

– MOST ARE PILOT STUDIES

– MUST INCLUDE THE HIGHEST POSSIBLE SOLUBILIZATION AGENTS - ALCOHOLS CAN BE USED.

FRACTURING TECHNOLOGIES TO ENHANCEFRACTURING TECHNOLOGIES TO ENHANCEIN-SITU REMEDIATIONIN-SITU REMEDIATION

INJECTION RATES > GW FLOW

MOVE CONTAMINANTS OUT & MOVE IN THE REACTANTS.