OPTIONS FOR TREATING & MONITORING OF HAZARDOUS MATERIALS

SEPARATION PROCESSES BASIC CONCEPTS SPECIFICATIONS FOR PURITY THE FRACTION NEEDS TO BE REMOVED TO MEET TARGET CONCENTRATIONS THE CONCENTRATION OF THE RECOVERED BYPRODUCT

SEPARATION PROCESSES

SEPARATION FACTOR WHICH IS ALSO CALLED THE DISTRIBUTION COEFFICIENT

SEPARATION FACTOR WHAT THE VALUE MEANS

SEPARATION FACTOR THE SEPARATION IS A RESULT OF EITHER –CHANGE IN CHEMICAL EQUILIBRIUM –TRANSPORT RATE GOVERNED PROCESS –MECHANICAL SEPARATION

SEPARATION PROCESSES PROCESSES CAN BE USED IN SERIES OR PARALLEL TO SEPARATE COMPLEX MIXTURES AND CAN INCLUDE RECYCLE OF STREAMS

MECHANICAL SEPARATIONS IMPOSE SOME FORCE ON THE SYSTEM TO OBTAIN SEPARATIONS

EXAMPLE OF SPECIALIZATION - FILTRATION CONVENTIONAL FILTRATION –REMOVES PARTICULATE BASED ON THE OPEN AREA IN THE FLOW CROSS- SECTION –CAN BE MADE OF MANY MATERIALS –CAN BE CONTINUOUS, LIKE BELTS, OR BATCH, LIKE A SAND FILTER

RANGES OF OPERATION - FILTRATION

CONVENTIONAL FILTRATION SEPARATION PARAMETERS CLOTH OR WIRE FILTERS 1

CONVENTIONAL FILTRATION SEPARATION PARAMETERS

UNITS ARE DESIGNED TO MAXIMIZE FLOW PER UNIT AREA (FLUX) FOR SPECIFIED PARTICULATE SIZES IN SPECIFIED FLUID CAN BE ENHANCED BY USE OF VACUUM

CONVENTIONAL FILTRATION SEPARATION PARAMETERS

MICROFILTRATION SEPARATION OF PARTICLES OF ONE SIZE FROM PARTICLES OF ANOTHER SIZE IN THE RANGE OF APPROXIMATELY 0.01 µTHROUGH 20 µ THE FLUID MAY BE EITHER A LIQUID OR A GAS

MICROFILTRATION FLOW PATTERNS –CROSSFLOW SEPARATION A FLUID STREAM RUNS PARALLEL TO A MEMBRANE. THERE IS A PRESSURE DIFFERENTIAL ACROSS THE MEMBRANE. THIS CAUSES SOME OF THE FLUID TO PASS THROUGH THE MEMBRANE, WHILE THE REMAINDER CONTINUES ACROSS THE MEMBRANE, CLEANING IT. –DEAD-END FILTRATION OR PERPENDICULAR FILTRATION. IN DEAD-END FILTRATION, ALL OF THE FLUID PASSES THROUGH THE MEMBRANE ALL OF THE PARTICLES THAT CANNOT FIT THROUGH THE PORES OF THE MEMBRANE ARE STOPPED

MICROFILTRATION CONSTRUCTION –MATERIALS OF CONSTRUCTION - MEMBRANE FILTERS CAN BE MANUFACTURED OF VARIOUS POLYMERIC MATERIALS METALS CERAMICS

MICROFILTRATION MEMBRANES PORE STRUCTURE – MEMBRANES WITH CAPILLARY- TYPE PORES CALLED SCREEN MEMBRANES PREFERRED FOR APPLICATIONS INCLUDING OPTICAL AND ELECTRON MICROSCOPY, CHEMOTAXIS, EXFOLIATIVE CYTOLOGY, PARTICULATE ANALYSES, AEROSOL ANALYSES, GRAVIMETRIC ANALYSES AND BLOOD RHEOLOGY

MICROFILTRATION MEMBRANES PORE STRUCTURE –MEMBRANES WITH TORTUOUS-TYPE PORES CALLED DEPTH MEMBRANES. LABYRINTH OF INTERCONNECTING ISOTROPIC PORES RECOMMENDED FOR GENERAL PRECISION FILTRATIONS, ELECTROPHORESIS, STERILIZATION OF FLUIDS, CULTURING OF MICROORGANISMS

ULTRAFILTRATION 3 ALSO CALLED MOLECULAR FILTRATION –USED TO SEGREGATE SUBSTANCES ACCORDING TO MOLECULAR WEIGHT (MW) AND SIZE –BASED ON A PRESSURE DIFFERENTIAL ACROSS THE SEMIPERMEABLE MEMBRANE TO DRIVE PERMEABLE MATERIALS THROUGH THE MEMBRANE –MEMBRANES USED IN MOLECULAR FILTRATION HAVE PORE DIAMETERS RANGING FROM 1 TO 1,000 ANGSTROMS (Å).

ULTRAFILTRATION WILL SEPARATE PARTICLES RANGING FROM 100 TO 10 6 DALTONS PARTICLES WITH MW OR SIZE LESS THAN THE MEMBRANE MOLECULAR WEIGHT CUT OFF (MWCO)PASS THROUGH THE MEMBRANE AND EMERGE AS PERMEATE SOLUTES WITH GREATER MW OR SIZE ARE RETAINED BY THE MEMBRANE AS RETENTATE AND ARE CONCENTRATED DURING THE MOLECULAR FILTRATION PROCESS.

ULTRAFILTRATION TYPICAL SEPARATION CAPABILITY

REVERSE OSMOSIS HYPERFILTRATION, IS THE FINEST FILTRATION KNOWN PROCESS WILL ALLOW THE REMOVAL OF PARTICLES AS SMALL AS IONS FROM A SOLUTION USED TO PURIFY WATER AND REMOVE SALTS AND OTHER IMPURITIES IN ORDER TO IMPROVE THE COLOR, TASTE OR PROPERTIES OF THE FLUID CAN BE USED TO PURIFY FLUIDS SUCH AS ETHANOL AND GLYCOL, WHICH WILL PASS THROUGH THE REVERSE OSMOSIS MEMBRANE, WHILE REJECTING OTHER IONS AND CONTAMINANTS

REVERSE OSMOSIS USES A MEMBRANE THAT IS SEMI- PERMEABLE CAPABLE OF REJECTING BACTERIA, SALTS, SUGARS, PROTEINS, PARTICLES, DYES, AND OTHER CONSTITUENTS THAT HAVE A MOLECULAR WEIGHT OF GREATER THAN DALTONS

REVERSE OSMOSIS

SEPARATION OF IONS WITH REVERSE OSMOSIS IS AIDED BY CHARGED PARTICLES –DISSOLVED IONS THAT CARRY A CHARGE, SUCH AS SALTS, ARE MORE LIKELY TO BE REJECTED BY THE MEMBRANE THAN THOSE THAT ARE NOT CHARGED, LIKE ORGANICS –THE LARGER THE CHARGE AND THE LARGER THE PARTICLE, THE MORE LIKELY IT WILL BE REJECTED

NANOFILTRATION FORM OF FILTRATION THAT USES MEMBRANES TO PREFERENTIALLY SEPARATE DIFFERENT FLUIDS OR IONS NOT AS FINE A FILTRATION PROCESS AS REVERSE OSMOSIS, BUT IT ALSO DOES NOT REQUIRE THE SAME ENERGY TO PERFORM THE SEPARATION

NANOFILTRATION USES A MEMBRANE THAT IS PARTIALLY PERMEABLE TO PERFORM THE SEPARATION, BUT THE MEMBRANE'S PORES ARE TYPICALLY MUCH LARGER THAN THE MEMBRANE PORES THAT ARE USED IN REVERSE OSMOSIS. USED TO SEPARATE A SOLUTION THAT HAS A MIXTURE OF SOME DESIRABLE COMPONENTS AND SOME THAT ARE NOT DESIRABLE

NANOFILTRATION EXAMPLE IS THE CONCENTRATION OF CORN SYRUP NANOFILTRATION MEMBRANE ALLOWS THE WATER TO PASS THROUGH THE MEMBRANE WHILE HOLDING THE SUGAR BACK, CONCENTRATING THE SOLUTION

NANOFILTRATION CAPABLE OF CONCENTRATING SUGARS, DIVALENT SALTS, BACTERIA, PROTEINS, PARTICLES, DYES, AND OTHER CONSTITUENTS THAT HAVE A MOLECULAR WEIGHT GREATER THAN 1000 DALTONS. NANOFILTRATION IS AFFECTED BY THE CHARGE OF THE PARTICLES BEING REJECTED –PARTICLES WITH LARGER CHARGES ARE MORE LIKELY TO BE REJECTED THAN OTHERS –NOT EFFECTIVE ON SMALL MOLECULAR WEIGHT ORGANICS, SUCH AS METHANOL.

NANOFILTRATION COMPARISON OF ULTRAFILTRATION, NANOFILTRATION AND REVERSE OSMOSIS 5

ELECTRODYALYSIS 6,7 ELECTROMEMBRANE PROCESS –IONS ARE TRANSPORTED THROUGH ION PERMEABLE MEMBRANES FROM ONE SOLUTION TO ANOTHER UNDER THE INFLUENCE OF A POTENTIAL GRADIENT –ELECTRICAL CHARGES ON THE IONS ALLOW THEM TO BE DRIVEN THROUGH THE MEMBRANES FABRICATED FROM ION EXCHANGE POLYMERS –APPLYING A VOLTAGE BETWEEN TWO END ELECTRODES GENERATES THE POTENTIAL FIELD REQUIRED FOR THIS

ELECTRODYALYSIS

GENERAL APPLICATIONS –MEMBRANES USED IN ELECTRODIALYSIS HAVE THE ABILITY TO SELECTIVELY TRANSPORT IONS HAVING POSITIVE OR NEGATIVE CHARGE REJECT IONS OF THE OPPOSITE CHARGE CONCENTRATION, REMOVAL, OR SEPARATION OF ELECTROLYTES

ELECTRODYALYSIS SPECIFIC APPLICATIONS –DESALINATION AND WATER TREATMENT –PROCESSING FOOD –CHEMICAL AND PHARMACEUTICAL PRODUCTS.

EQUILIBRIUM SEPARATION METHODS THESE INCLUDE ALL THE PROCESSES THAT CHANGE PROCESS CONDITIONS TO AFFECT A CHANGE IN THE CHEMICAL EQUILIBRIUM IN THE SYSTEM –THEY INVOLVE THE MIXING OF TWO PHASES AT AN INTERFACE –THE SEPARATION RESULTS IN A TARGET COMPONENT INCREASING IN AMOUNT (CONCENTRATION) IN ONE PHASE AND DECREASING IN AMOUNT IN THE OTHER PHASE

EQUILIBRIUM SEPARATION METHODS THE NUMBER OF PROCESSES IN EACH GROUP IS IN THE HUNDREDS

EXAMPLES OF SEPARATION PROCESSES EVAPORATION –INDUCES A PHASE CHANGE BY HEATING –MORE VOLATILE COMPONENTS GO TO THE VAPOR PHASE –LESS VOLATILE COMPONENTS GO TO THE LIQUID PHASE

EVAPORATION

TYPICAL EQUILIBRIUM DIAGRAM

LIQUID-LIQUID EXTRACTION MIXING OF TWO IMMISCIBLE LIQUID PHASES MOBILE COMPONENT DISTRIBUTES BETWEEN THE TWO PHASES

LIQUID-LIQUID EXTRACTION TYPICAL EQUILIBRIUM DIAGRAMS TAKEN FROM: Treybal, R. E., Mass-Transfer Operations, 2 nd Ed., McGraw-Hill, 1968

LIQUID-LIQUID EXTRACTION TYPICAL PROCESS FLOWSHEET

CRYSTALLIZATION SOLUTIONS ARE SUPERSATURATED SO THAT CRYSTALLIZATION CAN OCCUR TYPICAL METHOD IS A COMBINATION OF HEATING AND VACUUM AS THE SOLUTION IS COOLED, THE CRYSTAL WILL PRECIPITATE OUT ON SEED NUCLEI OR EXISTING CRYSTALS

CRYSTALLIZATION TYPICAL EQUILIBRIUM DIAGRAM

CRYSTALLIZATION USING THE EQUILIBRIUM DIAGRAM IT HAS 11 REGIONS WHICH REPRESENT DIFFERENT COMBINATIONS OF SOLIDS, LIQUIDS, AND COMPOSITIONS THE UPPER LEFT "LIQUID SOLUTION" REGION REPRESENTS MAGNESIUM SULFATE DISSOLVED IN WATER AT ANY TEMPERATURE, A VARIETY OF COMPOSITIONS ARE POSSIBLE

CRYSTALLIZATION USING THE EQUILIBRIUM DIAGRAM –THE MAIN CURVED LINE (E, P1, P2, P3) IS THE SATURATION CURVE –AT 300 K, A SATURATED SOLUTION WILL HAVE ABOUT 0.3 G SULFATE/G SOLUTION. –RIGHT OF THE MINIMUM, THE CURVE REPRESENTS THE SOLUBILITY OF SULFATE IN WATER –LEFT OF THE MINIMUM REPRESENTS THE SOLUBILITY OF WATER IN SULFATE

USING THE EQUILIBRIUM DIAGRAM REGIONS THE RIGHT OF THE SATURATION CURVE REPRESENT SOLID-LIQUID AND SOLID-SOLID MIXTURES –THERE ARE ONLY TWO POSSIBLE SOLID COMPOSITION FOR CRYSTALS AND COMPOSITIONS OF THESE REGIONS ARE READ AT THE SIDES –EITHER ANHYDROUS MAGNESIUM SULFATE –OR MAGNESIUM SULFATE HEPTAHYDRATE

USING THE EQUILIBRIUM DIAGRAM REGIONS AT THE BOTTOM AND THE FAR RIGHT REPRESENT COMPLETE SOLIDIFICATION TO FORM VARIOUS SOLID PHASES THE TRIANGLE AT THE LOWER LEFT REPRESENTS MIXTURES OF (WATER) ICE AND SATURATED SOLUTION

USING THE EQUILIBRIUM DIAGRAM THE MINIMUM POINT ON THE SOLUBILITY CURVE (PT. E) IS CALLED THE EUTECTIC AND IT IS UNIQUE IN THE SYSTEM – THIS POINT, THE LIQUID AND SOLID PHASES HAVE THE SAME COMPOSITION –COORDINATES OF THE EUTECTIC POINT ARE THE EUTECTIC TEMPERATURE AND THE EUTECTIC COMPOSITUSING THE EQUILIBRIUM DIAGRAM –BOTH –ION

LEACHING A PROCESS SIMILAR TO LIQUID- LIQUID EXTRACTION EXCEPT THE SOLUTE (COMPOUND OF INTEREST) DISTRIBUTES BETWEEN AN IMMISCIBLE SOLID AND LIQUID PHASE LIQUID SOLVENT LEACHES THE SOLUTE OUT OF THE SOLID

LEACHING

ADSORPTION PROCESS THAT IS THE OPPOSITE OF LEACHING BECAUSE THE SOLUTE IS TRANSFERRED TO THE SOLID PHASE TYPICAL PROCESS IS BATCH WITH PARALLEL UNITS –ONE UNIT IS ADSORBING SOLUTE –THE OTHER IS BEING REGENERATED

ADSORPTION CAN BE USED FOR REMOVING MATERIALS FROM LIQUIDS OR GASES –FOR GASES IT IS POSSIBLE TO REGENERATE USING REDUCED PRESSURE –FOR LIQUIDS OR GASES, REGENERATION CAN BE OBTAINED BY HEATING

ADSORPTION MODEL OF THE PROCESS

ADSORPTION CHROMATOGRAPHY IS A VARIATION ON ADSORPTION TYPICAL EXAMPLE SHOWING CFC’S MEASURED IN THE AIR AT UPPER ELEVATIONS 8

RATE BASED SEPARATION PROCESSES PROCESSES THAT USE THE RELATIVE RATE OF PERMEATION OF COMPONENTS THROUGH A MEMBRANE AS A BASIS FOR SEPARATION –TYPICALLY ONE COMPONENT HAS A HIGHER LEVEL OF SOLUBILITY IN THE MEMBRANE THAN THE OTHER, SO IT IS MORE READILY ABSORBED –DIFFUSIVITY IS ALSO A FACTOR, AS THE COMPONENTS NEED TO MOVE THROUGH THE MEMBRANE

RATE BASED SEPARATION PROCESSES TOTAL FLUX IS GENERALLY AFFECTED BY SYSTEM PRESSURES MANY OF THESE PROCESSES WERE DISCUSSED IN THE FILTRATION SECTION I.

RATE BASED SEPARATION PROCESSES SUMMARY OF TYPICAL PROCESSES

EXAMPLE OF EXTREME CONCENTRATION FOR RECOVERY OF t-Pa (TISSUE PLASMINOGEN ACTIVATOR) INCLUDES FOUR STEPS TO CONCENTRATE BY 1800 TIMES

SEQUENCE OF ACTIVITIES

EXAMPLE OF CONCENTRATIONS IN NATURAL MATERIALS DATA ON THE FOLLOWING TABLE INDICATES COMPONENTS FOUND IN GRAPES 9

EXAMPLE OF CONCENTRATIONS IN NATURAL MATERIALS SIMILAR DATA IS ALSO AVAILABLE FOR STRAWBERRIES 10