Download Polymers in the environment

Polymers in the environment
- Fate and Effects
Roald Kommedal
Associate Prof. Environmental Biotechnology, IMN – Chemistry and Environment
University of Stavanger
uis.no
11/17/2015
Bacterial lunch!!
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Organic carbon in the Environment
 Biomass: (Plants, Algae,
Animals, Microorganisms…)
 Soil and Sediments:
Biopolymers and Particulate
Organic Matter
 Aquatic: Dissolved and
Particulate Organic Matter
 Litosphere: Petroleum,
Coals
Polymeric (<10 nm or <1000 kDa)
and
Particulate (>Polymer)
Organic Matter (P&POM)
dominates in all environments
(apart from the deep ocean…)
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The FAST (short) and SLOW (long) C-cycle
Refractory
DOM
CO2
Mono
mers
Mono
mers
P&PO
M
Biopolym
ers
Cells,
Organ
isms
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The Microbial Loop
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(Azam et al., 1982)
Decomposers
Bacteria
Yeast
Cilliates
Moulds
Amoeba
Flagellates
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Bacterial Physiology:
Bacterial cell membrane = Molecular sieve (∼1kDa)
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Bacterial metabolism
Example: Aerobic organoheterothrophic growth, Energy Yield: 38 mole ATP/mole Glucose
Substrate:
Substrat:
C 6 H 12 O 6 Electron donor
Cell synthesis
(assimilation,
anabolism)
Glycolysis
Macro
and
micronutrients
Cellemasse
Cell
mass
ADP
Energy generation
(dissimilation,
or catabolism )
Energi
Energy
ATP
CSource
Karbon
Carbon
CAC
Interne
intermediates
ATP
Citric
Acid
Cycle
2 NAD +
2 NADH
Electron
acceptor
½ O2
H 2O
ADP
CO2
CO2
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C6H12O6 + 2.7 O2 + 0.7 NH3  0.7 C5H7NO2 + 2.7 CO2 + 4.7 H2O
Extracellular metabolism
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The polysaccharide system
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Extracellular depolymerization enzymes
α-Amylase
α-Glucosidase
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Depolymerisation of Natural occuring P&POM
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Degradation mechnisms of polymers
Natural/Biopolymers
Synthetic Polymers
 Extracellular Enzymes
 Phagocytosis
 Biological chemical
depolymerization (e.g. H2O2,
1O , 3O )
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 Physio-chemical
depolymerization (UV, Fenton,
O3, rOS)
 Physical depolymerization
(Temperature, Shear
degradation
 Biological chemical
depolymerization (e.g. H2O2,
1O , 3O )
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 Physio-chemical
depolymerization (UV, Fenton,
O3, rOS)
 Shear degradation
 Adsorption and deposition
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Effect of polymers

Low toxicity
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Low ecotoxicity
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Acute
Dose-Response
Genetic
Carcinogenic
Reproduction
Sub-toxic effects
Good
Aquatic
Soil
Sediment
Terrestrial
Low degradability
High adsobtion
High stability
High environmental
accumulation
Moderate mobility
No good
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Polyacrylamide – Stay polymerized, or…?
→
 Uses: Water treatment, plastic
surgary, gel and viscosity
enhancers, soil conditioning
 Non-toxic
 Non-biodegradable
 Highly adsorbent
 High stability
 High environmental accumulation
n
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Toxic (Neurotoxin)
Reproductive toxic
Genotoxic
Carcinogenic
Non-adsorbent
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Digestion ways
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