OPTIONS FOR TREATING & MONITORING OF HAZARDOUS MATERIALS

1. OPTIONS FOR TREATING & MONITORING OF HAZARDOUS MATERIALS

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

3. SEPARATION PROCESSES

4. SEPARATION PROCESSES • SEPARATION FACTOR • WHICH IS ALSO CALLED THE DISTRIBUTION COEFFICIENT

5. SEPARATION FACTOR • WHAT THE VALUE MEANS

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

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

8. MECHANICAL SEPARATIONS • IMPOSE SOME FORCE ON THE SYSTEM TO OBTAIN SEPARATIONS

9. 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

10. RANGES OF OPERATION - FILTRATION

11. CONVENTIONAL FILTRATION SEPARATION PARAMETERS • CLOTH OR WIRE FILTERS1

12. CONVENTIONAL FILTRATION SEPARATION PARAMETERS

13. 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

14. CONVENTIONAL FILTRATION SEPARATION PARAMETERS

15. 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

16. 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

17. MICROFILTRATION • CONSTRUCTION • MATERIALS OF CONSTRUCTION - MEMBRANE FILTERS CAN BE MANUFACTURED OF • VARIOUS POLYMERIC MATERIALS • METALS • CERAMICS

18. 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

19. 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

20. ULTRAFILTRATION3 • 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).

21. ULTRAFILTRATION • WILL SEPARATE PARTICLES RANGING FROM 100 TO 106 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.

22. ULTRAFILTRATION • TYPICAL SEPARATION CAPABILITY

23. 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

24. 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 150-250 DALTONS

25. REVERSE OSMOSIS

26. 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

27. 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

28. 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

29. 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

30. 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.

31. NANOFILTRATION • COMPARISON OF ULTRAFILTRATION, NANOFILTRATION AND REVERSE OSMOSIS5

32. ELECTRODYALYSIS6,7 • 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

33. ELECTRODYALYSIS

34. 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

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

36. 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

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

38. 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

39. EVAPORATION

40. EVAPORATION • TYPICAL EQUILIBRIUM DIAGRAM

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

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

43. LIQUID-LIQUID EXTRACTION • TYPICAL PROCESS FLOWSHEET

44. 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

45. CRYSTALLIZATION • TYPICAL EQUILIBRIUM DIAGRAM

46. 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

47. 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

48. 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

49. 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

50. 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