Lect 1 Appen v Micro

8/13/2019 Lect 1 Appen v Micro

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Environmental Microbiology, Sewage

treatment and Industrial Microbiology

Dr Mark Ashby1. Tue Oct 26 Waste Water Treatment

2. Mon Nov 1. Water Quality in Kingston Harbour issues.

3. Tue Nov 2.Terrestrial Environments

4. Mon Nov 8. Nutrient cycling5. Tue Nov 9 Nitrogen cycle/nitrogen fixation ,

6. Mon Nov 15 Freshwater, photosynthesis. The sea

7. Tue Nov 16 Extreme Environments.

8. Mon Nov 22 Comparative GenomicsCourse Website wwwbiochem.uwimona.edu.jm:1104/bc31M/

Recommended texts. Brock Biology of microrganisms 8, 9, 10thed.

Microbiology Prescott at al 3, 4, 5thed.


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Dr Ashby Labs

Oct25 Visit to UWI sewage plant

Nov 1 Visit to Portmore sewage plant. Bus leaves at

1pm prompt

Nov 8 Isolating antibiotic producers and analysis ofwater (MPN method)

Nov

15

Isolating antibiotic producers and analysis of

water continued.

Nov

22

Isolating antibiotic producers and analysis of

water finish.


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Useful Definitions/Terms Modes of Nutrition

Heterotroph; organism that uses reduced, preformed organic molecule as the principle

carbon source

Photo(lithotrophic) autotroph Photosynthesises using inorganic C as e-source and CO2as

C source.

Photo(organotrophic)heterotroph photosynthesise using organic C as e-donors and simple

organic C as C source.

Chemoautotroph chemolithotroph oxidise reduced inorganic compounds to get energy and

e-. CO2C source

Chemoheterotroph Chemoorganotrophic heterotroph Use organic compounds As sources

of energy, e-and C.

Autotroph CO2as source of C

Facultative anaerobe does not require O2but grows better with it.

Fermentation organic molecules function as electron donors and acceptors

Obligate anaerobes cannot grow in presence of O2

Microaerophiles require low % O2

Organotroph Use reduced organic C as e source

Phototroph use light for energy

Oligotrophic environmentcontains low levels of nutrients


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Waste Water Treatment

Wastewater comes from sewage, house washing waste

and industrial effluent.This water contains a high DOM

it will cause eutrophication and deoxygenation of rivers

And may contain poisonous compounds

and pathogenic organisms.


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3 stages of treatment.

Primary.This is only a physical separation to remove solid matter.

Effluent is allowed to settle for a few hours.

Secondary.The organic and nutrient load is decreased by microbial activity

Up to 95% so that the effluent is of a quality

to be able to go into rivers.

Tertiary.

This is a complete treatment, but it is very expensive

and not used much.


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Primary Treatment.

Sewage entering the system passes through a grate to remove

large debris branches, tyres! And a smaller grate filter out

smaller things

a grit tank to get rid of sand and gravel.Then it is allowed to sit in the settling tank.

About half the suspended organic solids settle at the bottom as

sludge or biosolids.

The sludge is also further treated.About 20-30% of the Biochemical oxygen demand (BOD)

is removed by primary treatment.


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Biochemical oxygen demand

This is an indirect measure of the dissolved O2required to

oxidise the biodegradable organic matter.

Sample is diluted and sealed in a bottle with bacteria.

Measure dissolved oxygen after 5 days.


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Secondary Treatment.

Can be divided into anoxic or oxic treatment processes


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Anoxic

Complex series of digestive and fermentative reactions by a

mixture of bacteria. It can remove 95% BOD.

This is the choice if there is a lot of insoluble matter

cellulose, industrial waste.

Degradation is carried out in large tankssludge digestors or bioreactors.

Molecular components are digested and fermented to FA, H2, CO2.

FA then to acetate, CO2and H2.

These are substrates for methanogenic bacteria to make methane.Major products are methane and CO2. Used or burnt off.


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Anoxic Sludge Digester


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Activated sludge movie

..\..\..\Desktop\Acslud

ge.mov

..\..\..\Desktop\Effluent.mov
http://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Effluent.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.mov


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Anoxic sludge digestion


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Aerobic

There are several kinds of aerobic decomposition processes.

Trickling filter and activated sludge are the most common.

Trickling filter is a bed of crushed rock, ~2m thick.

Wastewater is sprayed on the top (UWI plant).

Liquid slowly passes through the rock, organic matter absorbs to

the rock and microbial growth takes place.

Complete mineralisation of organic matter takes place.

Most common is activated sludge.Wastewater is mixed and aerated in a large tank


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Trickling Filter


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Activated sludge movies

..\..\..\Desktop\Acslud

ge.mov
http://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.movhttp://localhost/var/www/apps/conversion/Desktop/Acsludge.mov


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Microbial activity in activated sludge.

Slime forming bacteria like Zoogloeagrow and form flocs.

Small animals and protozoa attach to these.

Process of oxidation is similar to the trickling bed.

Effluent containing flocs goes to settling tanks. Flocs settle.

Some floc material is recirculated.Water spends 5-10 hours in sludge tank, too short for complete oxidation.

Main process is absorption of organic matter to the floc.

BOD of liq waste is reduced by ~95%.

Most BOD is in the flocs. BOD reduction then takes placeby digestion of the flocs in the sludge digestor.


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Anaerobic treatment has advantages over aerobic.

Methane is produced and the sludge has less volume and

can be dried easily. But it can contain concentrated heavy metals.

The sludge can be further treated aerobically.

These AAOanaerobic-anoxi-oxic treatment.


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Anaerobic digestors.

These can be used to further treat aerobically treated sewage.

Or for very highly concentrated sewage.

Vats have heating venting, mixing, sludge seeding, draw-off.

Protozoa and fungi are insignificant.2 step process.

1stnon-methanogenic, faculatively or obligately anaerobic.

Get H2and CO2.

2ndstep get methane. Products are methane and CO2.

Opt temp 35-37C and ph 6-8.Get a better reduction in volume of sludge.


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Oxidation ponds or lagoons.

This is very simple treatment used in rural areas,

particularly suited for tropical areas (Portmore

sewage treatment Plant).

Take up a large area, are less than 3m deep (allow light to penetrate).

Heterotrophic bacteria degrade organic matter.

Algae/cyanobacteria thrive producing oxygen,

allowing continued heterotrophic growth.

There are odour problems and the process can take over a week.


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Lagoon movie

..\..\..\Desktop\Lagoon.mov
http://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.movhttp://localhost/var/www/apps/conversion/Desktop/Lagoon.mov


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Some considerations for lagoon treatment.

These should be the first choice for tropical/3rdworld countriesas they are low tech.

There is a cycling between the heterotrophic and algae to remove BOD.

A diurnal effect. Often quite high algal growth due to high nutrients

and light. Mixing by wind is important.Get a sludge layer 150-300mm deep.

Ponds working well may only need dredging every 10-15years.

Must not be


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Tertiary treatment

This is used if the water is released somewhere which

is a fragile environment (wetlands) or for drinking.Tertiary treatment may be needed to remove nitrates and phosphates

(Lead to eutrophication).

Reed beds (artificial wetlands) can be used to remove these nutrients.


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Water Purification

Water treated by secondary treatment is suitable for release intorivers and the sea.

Water for drinking must be further treated.

Suitable water, often from a river

1st

taken into sedimentation tanks to allow solid things to settle.2nd coagulation tanks where chemicals containing Fe & Al are

added to generate flocks to trap bacteria.

3rd it is filtered.

4th passed through fine sand beds to remove more matter and microbes.

5th it is chlorinated to remove remaining microbes and oxidise

any organic matter. Sufficient Cl2is added so that some is left over.


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Sewage Visits

Sensible shoes please

Mon Oct 25 leave in bus at 2pm. Bring

notebook & camera (optional, but dontdrop it)

Mon Nov 1. As above but bus leavesprompt at 1pm and it will not wait if you arelate (see me if you have problemsbeforehand).

Documents

Lect 1 Appen v Micro