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77 Cards in this Set
- Front
- Back
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Pathogen
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Disease causing microorganism
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Infection
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Process in which microorganism
multiplies or grows lti li i h t in host |
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Enteric Pathogens
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Infect gastro-intestinal tract
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1854 Cholera
Epidemic in London |
First time disease associated with
water supply john Snow |
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Diarrheal disease
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4.1% of the total daily global
burden of disease |
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Cause Diarrhoe
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88% of cases due to unsafe water
supply, sanitation and hygiene |
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Helminths
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worms
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Protozoa
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Single cell eukaryote animals
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Bacteria
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prokaryotes
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Viruses
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DNA or RNA in protein coat?
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Rotavirus
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Causes Diarrhoea in children
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Norovirus
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Causes Diarrhoea in children and adults
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Adenovirus
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Resistant to UV inactivation
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Salmonella
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bacteria -Most common cause of diahrroea
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Vibrio cholerae
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bacteria-Cholera disease, fecal contaminated drinking water/food
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Shigella
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bacteria-S. dysenteriae causes severe disease
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E. coli
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Certain strains cause diarrhoea
(motys revenge) |
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Giardia
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Protozoa-Common infection in man causing chronic diarrhoea
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Cryptosporidium
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Protozoa-Diarrhoea, less chronic than Giardia
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Entamoeba
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protozoa-Amebic dysentery (only in 3
rd world countries) |
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Factors effecting concentration of pathogens
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Incidences of infection in community
Socioeconomic (related to health care, sanitation) Time of year Water consumption per capita |
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Indicator
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Indicator organisms used:
Monitor presence fecal contamination Effectiveness pathogen removal treatments |
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Principle
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Use simple non-pathogenic microorganisms of warm
blooded animals |
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Norms
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Norms are legally binding. In United States:
Sewage discharges should not exceed 200 fecal coliforms/100 ml Class A biosolids must not exceed Cl A bi lid t t d 1000 f l lif / t t l lid l d 1000 fecal coliforms/g total solids sludge, and must not exceed 3 Salmonella/4 g total solids sludge For drinking water, no more than 5% samples per month (>40) can be positive for total coliforms (note specific pathogens are regulated by requiring specific treatment processes) |
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Guidelines
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Guidelines not legally binding. In United States marine bathing water
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CT
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Disinfection for a given pathogen, pH and condition is a function of:
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Ozone
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Ozone (O3
) is a powerful oxidizing agent produced by passing an electric discharge through a stream of air or O2 good alternative to chlorine |
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UV
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Damages DNA (formation of cyclobutane from adjacent
bases, e.g. thymine dimerization) |
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Ammonia (NH3) is Toxic to Fish
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Nitrate is Toxic to Humans
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Biodegradation
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Definition: Biologically catalyzed transformation of
chemical resulting in simpler forms |
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Mineralization:
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Mineralization:
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Biotransformation:
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Transformation of pollutant by a biological process (eg
conversion of trinitrotoluene to triaminotoluene) |
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Growth Substrate, Primary Metabolism:
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Pollutant used as the primary energy and carbon source for microbial growth
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Cosubstrate, Cometabolism
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Biotransformation of a compound that does not
serve as an energy source eg oxidation of vinyl chloride by methane monooxygenase |
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Electron acceptor:
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The compound that receives electrons (and therefore is
reduced) in the energy-producing oxidation-reduction reactions that are essential for the growth of microorganisms and bioremediation. |
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Electron donor:
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The compound that donates electrons (and therefore is
oxidized). In bioremediation, the organic contaminant often serves as an electron donor. |
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Aerobic respiration
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The process whereby microorganisms use oxygen
as an electron acceptor. |
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Anaerobic respiration
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The process whereby microorganisms use a
chemical other than oxygen as an electron acceptor. Common 'substitutes' for oxygen are nitrate, sulfate, and iron. (Anoxic, Anaerobic) |
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Fermentation
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The process whereby microorganisms use an organic
compound (substrate) as both electron donor and electron acceptor, converting the compound to fermentation products such as organic acids Fe 3+ , NO3 - , SO4 2- , CO2 converting the compound to fermentation products such as organic acids, alcohols, hydrogen, and carbon dioxide |
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Reductive dehalogenation:
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A variation on biodegradation in which
microbially catalyzed reactions cause the replacement of a halogen atom on an organic compound with a hydrogen atom |
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Halorespiration:
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A biological reaction in which a halogenated
hydrocarbon is used as an anoxic electron acceptor to support microbial growth |
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Successive Use of Electron Acceptors
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Electron acceptors that yield
more energy for microbial growth are used first |
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General Categories of Persistence
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Structure of Xenobiotic Compoundz
Bioavailability Toxicity Limiting Environmental Factor Limiting Environmental Factor |
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General Structure-Biodegradability Trend
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Aerobic Degradation Structure Biodegradability
Trends: Increasing number of electron-withdrawing xenobiotic functional groups |
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Bioremediation
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The destruction or transformation of
hazardous pollutants by microorganisms to less harmful forms; in order to remediate a contaminated site (or effluent) |
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Engineered Bioremediation
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he biodegradation or
biotransformation is stimulated by an engineered intervention Typically the supply of nutrients, and electron acceptor (eg O2 ); in some cases electron donor or cosubstrate Only in a few applications, the addition of microorganisms or substances that increase pollutant dissolution (eg surfactant |
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Intrinsic Bioremediation
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The biodegradation or
biotransformation occurs naturally without any intervention, the technology is only monitoring and predicting the natural process. Usually the occurrence of biodegradation has to be demonstrated in several independent ways. Typically the intrinsic processes are anaerobic involving alternative electron acceptors present in the matrix. |
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Natural AA i ttenuation
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Is an expanded defi d dd fi i i f nition of
intrinsic bioremediation, including both biotic and abiotic processes. |
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in situ bioremediation:
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Treatment of soil and groundwater in
its original place. Usually involves infiltration wells for nutrients and water and extraction wells for movement of oxygen into the contaminated zone |
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Bioventing:
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in situ bioremediation in which air is infiltrated
into contaminated soil in the vadose zone; |
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Landfarming:
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Treatment of soil on the surface by adding
nutrients, irrigation nutrients irrigation and tilling and tilling. |
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Biopiles/Composting:
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Treatment of soil in actively aerated
windows, in some cases mixed with (organic) bulking agents |
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Slurry Reactor:
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Treatment of contaminated soil/sediment in a
slurry suspension in a reactor (usually CSTR) |
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Effluent Bioreactor:
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Treatment of effluent in a submerged
bioreactor, usually involves biomass immobilization (eg fixed filter, fluidized bed, UASB) |
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Biofiltration
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Treatment of contaminated off-gasses in an
unsubmerged bioreactor (eg compost filter, biotrickle filter |
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Biobarrier
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Treatment of a plume in a trench filled with
reactive material to promote biodegradation |
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Anerobic biodegradation
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from polutanat to biogas
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Overview Anaerobic Biodegradation
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Polymers
(proteins, polysaccharides) then to Monomers (sugars, amino acids, peptides) then to propinate or byruvate or acetate or co2 then to ch4 and co2 |
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Fermentation
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Use of partially oxidized intermediate as
electron acceptor |
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Volatile Fatty Acids (VFA):
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CH3COOH Acetic acid
CH3CH2COOH Propionic acid CH3CH2CH2COOH Butyric acid |
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Gaseous fermentation products
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Hydrogen
Carbon dioxide |
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Acetogenesis
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Conversion VFA & alcohols to H2
& acetate Typically endergonic reactions (means G’ is positive) H2 consuming syntrophic partner required Lowering H2 makes G’ negative even though G’ is positive |
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Autotrophic Methanogenesis
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CO2+4 H2 = CH4
+ 2 H2O |
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Acetoclastic Methanogenesis
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CH3COO-+ H+ = CH4
+ CO2 |
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Methylotrophic Methanogenesis
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CH3OH = 3 CH4+ CO2+ H2O
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Common Methanogens
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Methanosaete
Methanosarcina |
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Methyl Reductase: F430 Complex
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Catalyzes formation of disulfide bond
Catalyzes reduction methyl group to methane Requires Ni Containing Coenzyme 430 |
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Anaerobic Sludge Granules
physical: |
its sludge, its dense
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Anaerobic Sludge Granules
Microbial |
balanced microbial community
syntrophic partners closely associated high meth hi h th i ti it anogenic activity (0.5 to 2.0 g COD/g VSS.d) protection from toxic shoc |
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Granules
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Granules are favorable for syntrophic
partnerships greater H2 gradients enable faster flux |
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Nitrogen fixation
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microbial converstion of N2 to NH3
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Nitrogen assimilation
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ammonium becomes incorperated into an organic molecules
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ammoniafication(mineralization)
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organic molecules containing nitrogen are deamited, during decomposition of orgainic molucules producing ammonia
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nitrification
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aerobic chemolithotrophic bacteria collaborate to oxidize
NH3 The first oxidation product is NO2 .-NO2- is further oxidized by to NO3 |
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Denitrification (“dissimilative nitrate reduction”)
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reduction of nitrate by anaerobic heterotrophic bacteria,
producing N2 gas |
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Dissimilative nitrate reduction to ammonia (DNRA)
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reducti d ti f on of
nitrate by anaerobic heterotrophic bacteria , producing NH3 |
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annamox
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anaerobic oxidation of ammonia by autotrophic bacteria, canidatus,nh4 is electron doner no2 is acceptor
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