asce texas 2013 centennial
DESCRIPTION
http://www.texasce.org/displaycommon.cfm?an=1&subarticlenbr=246TRANSCRIPT
Sustainable Utilization of RO By-
Product Solids
By
Bijoy Krishna Halder, Vivek Tandon, Anthony Tarquin,
Guillermo Delgado
The University of Texas at El Paso
Agenda
Introduction
Challenges
Objective
Material Used
Micro Scale Test
Sample Preparation and Curing Condition
Compressive Strength Test
Conclusion
Introduction
Introduction
• Water is an important resource.
• To produce potable water, various techniques e.g. desalination
is used.
• One desalination process is The Concentrate Enhanced
Recovery Reverse Osmosis (CERRO©)
• However this process yield high concentration CaSO4 as RO
by-product.
Challenges
Challenges
The disposal of this waste CaSO4 by-product in an
environmentally friendly manner is an issue.
Objective
• Evaluate the feasibility of using RO by-product in cement
mortar and AACB (alkali activated complex binders) mortars .
Objective
Material Used
Material Used
• Cement (Type I/II OPC, ASTM C-150)
• Quickrete all purpose sand (ASTM C 33 )
• Water
• NaOH (10M)
• Sodium Silicate (Na2O:SiO2=1:1)
• CaSO4 salt, RBG (passing #16 sieve )
• Class F fly Ash
• Fly ash Property (Collected from Boral Material Technology)
Material Used (Cont.)
Component Results
SiO2 50.69 %
Al2O3 23.68 %
Fe2O3 4.68 %
SiO2+ Al2O3+ Fe2O3 79.05 %
CaO 13.19 %
MgO 1.62 %
SO3 1.78 %
Na2O 0.05 %
K2O 0.90 %
Total Alkalies (as Na2O) 0.64 %
Loss of Ignition, % LOI 1.69 %
Specific gravity 2.29 1
MICRO SCALE TEST
XRD Analysis of RBG
0 5 10 15 20 25 30 35 40 45 50 55 60 65
Br
Br
Br
H BBB B
BB
B
B
B
Inte
nsity
(A
.U)
2-Theta
B
B: Bassanite
Br: Brucite
H: Hallite
• Bruker D8 X-ray diffractometer
• Bassanite, (CaSO4, 0.5 H2O)
SEM Analysis of RBG
(a) (b)
SEM Analysis of RBG (Cont.)
SEM EDX of Rod Shape Particle
-1 0 1 2 3 4 5
0
1000
2000
3000
Mg
K
Na
K
S K
O K
Ca
L Cl K
Ca
K
Ca
K
Cou
nt P
er S
econ
ds
Energy, KeV
Cl K
SEM EDX of Gel layer
Laser Diffraction Particle Sizing of Fly
Ash
Parameter Outcome
D (0.1) 3.92 µm
D(0.5) 34 µm
D(0.9) 139.80 µm
Surface weighted mean D[3,2] 8.855 µm
Volume weighted mean D [4,3] 85.5 µm
Specific surface area 678 m2/kg
Mean particle size 65 µm
Sample Preparation
& Curing Condition
Sample Preparation (Cont.)
ASTM* C-109 (2008)
Cement: Sand: Mixing Liquid= 1:2.75:0.49
AACB mortar (Fly Ash:Sand= 1:2.75, Sodium Silicate: NaOH=0.67,
minimum base water 5% by mass of geopolymer paste )
Samples were prepared in 2 × 2 × 2 in..
*American Society of Testing material
Curing Process
• Tap Water (For standard samples)
• Cement Mortar cured at room temperature, submerging under
water.
• AACB mortars were kept at 75 ̊ C for total 3 days accelerated
curing.
Compressive Strength
Test (ASTM C 109-08)
Compressive Strength Test Result
Compressive Strength Test Result
Compressive Strength Test Result
Conclusion
Conclusion
• The compressive strength test results indicate that there is
feasibility of disposing RO byproduct CaSO4 in geopolymer
based mortars.