By: Zachary Bryan ScottDepartment of Civil and Environmental
EngineeringUniversity of California, Irvine
Wastewater Treatment:
Aerobic Biological Treatment of Wastewater• Cleans wastewaters• Generates Biomass (0.4g VSS/ g COD)
Anaerobic Biological Treatment• Cleans wastewaters – Many Types• Reduces biomass (0.05 g VSS/ g COD)• Can produce net energy
• Consider heating, transport, 4 ft3 CH4 / lb VS as manure
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3
•Reactor Assessment/Optimization• Design
• Process Modification
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Modify Reactor Conditions:pH, T, Feed Type, Feed interval,
Mixing Intensity, Nutrients
Current Industrial Use of Models is very limited
Pilot testing still dominant = higher costs = more time
CH4, CO2
H2, CO2 Acetate
Alcohols,
Carboxylic acids
(except acetate)
Fermentative microorganisms (Clostridia spp.)
Hydrogenophilicmethanogens: MSL,MBT, MMB,MCC
Acetophilicmethanogens: MSL
Acetogens
4% 76% 20%
24% 52%
28% 72%
Hydrolysis
Acetogenesis
Methanogenesis
Organic
Polymers
5Modified figure, Gujer and Zhender, 1979
Anaerobic Process:
Three Critical Measurements:Methane
Production Rates-
Flowcell Acetate Consumption
Rates-GC
Aceticlastic Methanogen Ribosomal DNA Copy # - qPCR
6 Batch ReactorsHighly Degraded Manure-Media
(MSL)Fed Acetic Acid
Acrylic, Rod Mixed Glass, Shaker-Mixed
Acrylic, Rod Mixed
Glass, Rod-Mixed
How are Organisms Identified and Quantified in mixed culture?
•Each taxonomic group has ribosomal DNA (rDNA) that is unique to its group
This information is available in public databases. ex: NCBI
•rDNA is extracted from samples
•quantitative Polymerase Chain Reaction assays quantify the DNA
•Technique requires prior knowledge of organism’s genome•Probes and primers complement and bind to target DNA
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Methods – Organism Quantification
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1.Collect Sample2.Extract and Purify DNA3.Quantify the DNA of important anaerobes
Releasing DNAThe key to good analysis is the total release of DNA from the
cell.
Use glass beads to beat cells in order to break the cell wall and membrane.
DNA Needs to be released by beating with glass beads
12Olson, UCI, CEE 263, 2008
Flowcell – Basic PrinciplesFirst Cell Measures Total Gas, Second Cell Measures MethaneGlass scrubber with 2 M NaOH to remove CO2. , Bromocresol Green Indicator, color transition, clear to green at pH 12
R1 R2
- 5 V +
Two Resistors in SeriesR1: 12k Ω , R2:Cd_S(1-50)k Ω
15 mC LED & 200 Ω R
Gas in Gas Out
FLOW-CELL
- +
Volts
800
850
900
950
1000
2cal-0pt5mL-min-5mL 05/05/2008 14:34:01 Flowcell 2 Bubbles 156Sample Rate =128Hz 2 points averaged Rate utilized: 64Hz
Minutes
mV
Plumping and Circuit Diagram, 6 ReactorsPhysical connections to Match Software Organization
R1 R3 R4R2 R5 R6
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USB Device PC
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