Selective Salt Recovery from Reverse Osmosis Brine - University of ...

Figure 48: Figure 37: XRD Spectra from Experiments 3 and 5-7 .....................................84
Figure 49: Pilot Schematic .................................................................................................89
Figure 50: Pilot Equipment on Site ....................................................................................93
Figure 51: Pilot Equipment including timer (far left), power supply (middle), titration
setup (front), and regeneration pump (far right) ........................................................94
Figure 52: Solenoid Valves at top of Columns ..................................................................95
Figure 53: Solenoid Valves at Bottom of Columns ...........................................................95
Figure 54: Control Sequence at Pilot Input including Pressure Reducer, Solenoid Valve,
Pressure Gauge, Needle Valve, and Pressure Relief Valve .......................................96
Figure 55: Pilot Project Schedule ......................................................................................97
Figure 56: SEM Images of Precipitate from Ambient pH Conditions .............................112
Figure 57: SEM Images of Precipitate from Low pH Conditions ...................................113
Figure 58: Semi Quantification of EDS Spectra Showing % Composition of Spheres
Identified by SEM ....................................................................................................115
Figure 59: Semi Quantification of EDS Spectra Showing % Composition of Needles
Identified by SEM ....................................................................................................117
Figure 60: SEM Image Showing Possible Amorphous Material .....................................119
Figure 61: XRD Spectra of Precipitate Samples..............................................................119
Figure 62: Overlaid Spectra from XRD Analysis ............................................................121
Figure 63: Calculated Salt Yield per Cubic Meter of RO Concentrate for each Week at
Ambient pH ..............................................................................................................122
Figure 64: Calculated Salt Yield per Cubic Meter of RO Concentrate for each Week at
Low pH ....................................................................................................................123
Figure 65: Difference in Yield between Precipitation at Ambient and Low pH Conditions123
Figure 66: Elution Curve for Week 2 ..............................................................................127
Figure 67: Normalized Elution Curve for Week 2...........................................................127
Figure 68: Elution Curve for Week 5 ..............................................................................128
Figure 69: Normalized Elution Curve for Week 5..........................................................128
Figure 70: Concentration of Cl, NO3, and SO4 on Resin Stripped (meq/g) .....................131
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