Transcript Pretreatment for Water Recovery System

Urine Pretreatment
for Wastewater Recovery
SEI 2008-09
Engineers who solved
Apollo 13’s problems
Overview
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Background
Objectives
Laboratory Tests
Distillation Simulation
Results Summary
Team Accomplishments
Future Tasks
Acknowledgements
Team Structure
Name
Major
Year
Position
Moriah Thompson
Biomedical Eng.
4
Project Lead
Sara Guest
Chemical Eng.
4
Data and Simulation Lead
Elizabeth Joachim
Biomedical Eng.
3
Lab Lead
David Moore
Civil Eng.
1
Assistant Lab Lead
Sandhya Ramesh
Biomedical Eng.
1
Logistics Lead and lab work
Marco Cienega
Mechanical Eng.
3
Assistant Logistics Lead
Blesson John
Biomedical Eng.
1
Webmaster
Water Use and Recovery
Water currently
resupplied via shuttle
Not economical or
practical to re-supply
water for long term
missions
ISS wastewater sources
Distribution
Consumption
Exhalation
Urination
Urine pretreatment protects
hardware and plumbing system
form clogging
Hygiene
Perspiration
Humidity
Condensate
1. Solids precipitation
2. Biofilm formation
Hygiene
Waste
Current Urine Pretreatment
“String of Pearls”
Not compatible
with reclamation
system
Urine and Fecal
collection Unit
Problem Statement
The current pretreatment method utilizes
a toxic chemical with little known
toxicological information that may be
detrimental to astronaut health over time.
Previous work
Supernatant Characterization
from urine MAP precipitation:
• TOC > EPA drinking water limit
• Organics and Inorganics
removal is needed
• High pH buffer
• Need to optimize precipitation
reaction
Chemical urine pretreatment:
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Sulfuric Acid
Sodium Benzoate
Acetic Acid
Glycolic Acid
Sodium Permangante
Phosphoric Acid
Work presented in the 11th International Conference on Engineering, Science, Construction, and
Operations in Challenging Environments (Earth & Space Conference)
Cascade Distillation Subsystem
currently used for water reclamation
Centrifugal vacuum distillation
Project Objective
Identify a non-toxic pretreatment
alternative that is compatible with a
distillation based water reclamation
system.
Project Tasks
• Task 1- Laboratory tests
– Select pretreatment chemicals
• Toxicity data, HMIS, pKa, Volatility
– Test chemicals’ pretreatment ability
• Task 2- Distillation simulation (Aspen)
– Research Cascade Distillation Subsystem
– Determine simulation operation conditions
– Simulate chemicals tested in Task 1
Task 1-Laboratory Test
Objective: Compare pretreatment chemicals
to sulfuric acid in stored urine (1g/L)
– Chemical: pH
– Physical: TSS, Turbidity
– Biological: Protein, Ammonia, DO
Chemicals Selected
• 1 g/L as active
ingredient
• Chosen based on
solubilty, pKa, and
toxicity
• Delivery system for
solid chemicals
depends on solubility
Sulfuric Acid
Fumaric Acid
Sorbic Acid
Boric Acid
Lactic Acid
Phthalic Acid
Experimental Methods
Urine collected
Urine collection
carboy
Samples are taken at
predetermined times
Analytical Methods
pH
TSS
Dissolved
Oxygen
Turbidity
Ammonia
Phenate Method
Protein Assay
Chemical Test Results
Average pH - Six Days
12
10
pH
8
Sulfuric
6
Fumaric
Sorbic
4
Boric
2
0
0
0,33
0,66
1
2
24
48
Time (hours)
72
96
120
144
Physical Tests Results
Average Turbidity - Six Days
Average TSS - Six Days
200
7
180
6
140
5
120
4
g/g0
NTU/NTU0
160
100
80
3
60
2
40
1
20
0
0
0
0,33 0,66
1
2
24 48
Time (Hours)
72
96
120 144
0
0,33 0,66
1
2
24 48
Time (Hours)
72
96
120 144
Biological Tests Results
Average Ammonia - Six Days
14
[mg/L]/[mg/L]0
12
10
8
6
4
2
0
2
24 48 72 96 120 144
Average Protein - Six Days
Time (Hours)
2,5
[mg/mL]/[mg/mL]0
0 0,330,66 1
2
1,5
1
0,5
0
0 0,33 0,66 1
2
24
48
Time (Hours)
72
96 120 144
Biological Tests Results
Average Dissolved Oxygen - Six Days
1,2
DO/DO0
1
0,8
0,6
0,4
0,2
0
0
0,33
0,66
1
2
24
Time (Hours)
48
72
96
120
144
Task 2- Simulation
Objectives:
– Determine % water recovery at proposed
operating conditions
– Determine % acid recovery at proposed
operating conditions
Simulation Conditions
Feed Conditions
Temperature °C
40
Pressure psi
14.69
Volume Fraction
Chemical
0.04
Water
0.96
Flash Operating
Conditions
Temperature °C
25-50
Pressure psi
0
One stage flash
(worst case scenario)
VAPOR
FEED
FLASH
LIQUID
Simulation results
• Sulfuric, fumaric, and boric are separable
from water in the flash operating range of
25-50°C
• Currently unable to simulate sorbic acid
• Separation Efficiency:
Results Summary
• Laboratory tests results:
– Chemicals tested do meet pretreatment requirements
for short term storage
– Chemicals tested do not meet pretreatment
requirements for long term storage
• Distillation results:
– Chemicals are separable from water in the flash
operating range of 25-50°C.
– Preliminary simulations indicate that high % chemical
removal is possible
Future Tasks
• Laboratory tests
– Lactic acid
– Phthalic acids
• Simulation
– Separation efficiencies
– Lactic acid
– Phthalic acids
Acknowledgements
Julianna Camacho
Dr. Autenreith
Dr. Pickering
Magda Lagoudas
Urine Video