urine pretreatment for wastewater recovery sei 2008-09 engineers who solved apollo 13’s problems
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Urine Pretreatmentfor Wastewater Recovery
SEI 2008-09Engineers who solved Apollo 13’s problems
Overview• 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
Urination
Distribution
Consumption Hygiene
HumidityCondensate
PerspirationExhalation
Hygiene Waste
Urine pretreatment protects hardware and plumbing system form clogging
1. Solids precipitation
2. Biofilm formation
Current Urine Pretreatment
“String of Pearls”
Urine and Fecal collection Unit
Not compatible with reclamation
system
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 workSupernatant 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:
• 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 Subsystemcurrently 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
– Chemical: pH– Physical: TSS, Turbidity– Biological: Protein, Ammonia, DO
Objective: Compare pretreatment chemicals to sulfuric acid in stored urine (1g/L)
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
Samples are taken at predetermined times
Urine collection carboy
Analytical Methods
TSS
Turbidity
pH
Dissolved Oxygen
AmmoniaPhenate Method Protein Assay
Chemical Test Results
Physical Tests Results
Biological Tests Results
Biological Tests Results
Task 2- SimulationObjectives:
– Determine % water recovery at proposed operating conditions
– Determine % acid recovery at proposed operating conditions
FEED
VAPOR
LIQUID
FLASH
Feed ConditionsTemperature °C 40
Pressure psi 14.69Volume Fraction
Chemical 0.04Water 0.96
Flash Operating Conditions
Temperature °C 25-50Pressure psi 0
One stage flash (worst case scenario)
Simulation Conditions
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