Oxygen Deoxygenation Environment pollution Prevent pollution

1. OXYGEN DEOXYGENATION

2. GROUP MEMBERS- (GROUP 08)
• AST/2022/056 - G.A.M.C.J . ADHIKARI
• AST/2022/057 - R.M.N. L. RATHNAYAKE
• AST/ 2022/058 - M.N.F. INSHIFA
• AST /2022/059 - M.K.F.HASNA.
• AST/ 2022/060- - J.A.K. WIRAJITH
• AST/ 2022/ 061 - D.D.I.S. DISSANAYAKE
• AST/2022/062- S.H.S.P .HEWAGE
• AST/2022/064- - K.KB. H.L.G GUNARATHNE
• AST /2022/065 - M.G.P. DULAKSHI
• AST/2022/051 - J.M.I.D. JAYASOORIYA

3. CONTENT
1.INTRODUCTION
2.CAUSES OF OCEAN DEOXYGENATION
3.OXYGEN DEOXYGENATION PROCESS
4.WHERE DOES DEOXYGENATION OCCUR?
5. METHODS USED TO DEOXYGENATE TO
WATER
6.ENVIRONMENTAL CONSEQUENCES OF
OXYGEN DEOXYGENATION IN AQUATIC
ECOSYSTEMS
7. OXYGEN DEOXYGENATION AFFECT THE
EFFICIENCY OF AEROBIC WASTEWATER
TREATMENT PROCESSES
8. CUTTING EDGE RESEARCH EFFORTS
FOCUSED ON UNDERSTANDING AND
MITIGATING OXYGEN DEOXYGENATION IN
THE ENVIRONMENT
9.THE RELATIONSHIP BETWEEN OXYGEN
DEOXYGENATION AND CLIMATE CHANGE
10. IMPORTANT OF OXYGEN
DEOXYGENTION

4. INTRODUCTION
• OXYGEN DEOXYGENATION" REFERS TO THE PROCESS OF REMOVING OXYGEN
FROM A SUBSTANCE OR ENVIRONMENT. THIS CAN OCCUR THROUGH VARIOUS
MEANS, DEPENDING ON THE CONTEXT. IN THE CONTEXT OF CHEMICAL
REACTIONS, DEOXYGENATION OFTEN INVOLVES THE REMOVAL OF OXYGEN ATOMS
FROM MOLECULES, RESULTING IN THE FORMATION OF NEW COMPOUNDS. IN
ENVIRONMENTAL SCIENCE, DEOXYGENATION CAN REFER TO THE DEPLETION OF
OXYGEN IN WATER BODIES, WHICH CAN HAVE HARMFUL EFFECTS ON AQUATIC
LIFE. THIS DEPLETION OFTEN OCCURS DUE TO FACTORS LIKE POLLUTION,
NUTRIENT RUNOFF, AND ALGAL BLOOMS, WHICH CAN CONSUME OXYGEN DURING
DECOMPOSITION.

5. CAUSES OF OCEAN DEOXYGENATION
1.CLIMATE CHANGE:
INCREASED TEMPERATURES LEAD TO REDUCED OXYGEN SOLUBILITY IN WATER, MAKING IT
HARDER FOR OXYGEN TO DISSOLVE AND STAY IN THE OCEAN.
CLIMATE CHANGE ALSO AFFECTS OCEAN CIRCULATION PATTERNS, WHICH CAN RESULT IN
OXYGEN-POOR ZONES.
2.NUTRIENT RUNOFF:
EXCESS NUTRIENTS FROM AGRICULTURE, SEWAGE, AND OTHER SOURCES CAN CAUSE
ALGAL BLOOMS.
WHEN THESE BLOOMS DIE AND DECOMPOSE, THEY CONSUME OXYGEN, LEADING TO LOW-
OXYGEN OR "DEAD" ZONES.
3.POLLUTION:
CHEMICAL POLLUTANTS LIKE FERTILIZERS AND PESTICIDES CAN DISRUPT MARINE
ECOSYSTEMS AND CONTRIBUTE TO OXYGEN DEPLETION.
INDUSTRIAL POLLUTION AND OIL SPILLS CAN ALSO HARM MARINE LIFE AND REDUCE
OXYGEN LEVELS.

6. 4.OVERFISHING:
REMOVING LARGE NUMBERS OF FISH CAN DISRUPT FOOD CHAINS AND LEAD TO IMBALANCES IN
MARINE ECOSYSTEMS.
THIS CAN INDIRECTLY CONTRIBUTE TO OXYGEN DEPLETION BY AFFECTING THE DISTRIBUTION
AND BEHAVIOR OF MARINE ORGANISMS.
5.NATURAL PROCESSES:
CERTAIN NATURAL EVENTS LIKE UPWELLING AND DEEP WATER MIXING CAN BRING LOW-OXYGEN
WATER TO THE SURFACE, AFFECTING LOCAL OXYGEN LEVELS.
HOWEVER, HUMAN ACTIVITIES CAN EXACERBATE THESE NATURAL PROCESSES AND AMPLIFY THEIR
IMPACT ON OCEAN DEOXYGENATION.

7. 1. INTRODUCTION OF NUTRIENTS: NUTRIENTS FROM SOURCES LIKE AGRICULTURAL RUNOFF OR
SEWAGE ENTER THE WATER, PROMOTING THE GROWTH OF ALGAE AND OTHER
MICROORGANISMS.
2. ALGAL BLOOMS:
EXCESSIVE NUTRIENTS LEAD TO ALGAL BLOOMS, WHERE ALGAE GROW RAPIDLY AND COVER
THE WATER SURFACE.
3. ALGAL DECAY:
WHEN THE ALGAE DIE, THEY SINK TO THE BOTTOM AND DECOMPOSE. THIS DECOMPOSITION
PROCESS CONSUMES OXYGEN FROM THE WATER.
4. MICROBIAL DECOMPOSITION:
MICROORGANISMS FURTHER DECOMPOSE THE ORGANIC MATTER, CONSUMING EVEN MORE
OXYGEN IN THE PROCESS.
OXYGEN DEOXYGENATION PROCESS

8. 5. OXYGEN DEPLETION:
AS OXYGEN IS CONSUMED BY DECOMPOSITION AND OTHER PROCESSES, OXYGEN LEVELS IN
THE WATER DECREASE, LEADING TO DEOXYGENATION.
6. IMPACT ON AQUATIC LIFE:
LOW OXYGEN LEVELS CAN BE HARMFUL OR EVEN LETHAL TO FISH AND OTHER AQUATIC
ORGANISMS, DISRUPTING ECOSYSTEMS AND LEADING TO DECLINES IN BIODIVERSITY.

9. WHERE DOES DEOXYGENATION OCCUR?
OXYGEN DEOXYGENATION CAN OCCUR IN VARIOUS ENVIRONMENTS, BUT IT'S MOST COMMONLY
OBSERVED IN AQUATIC ECOSYSTEMS, SUCH AS LAKES, RIVERS, ESTUARIES, AND OCEANS. HOWEVER,
IT CAN ALSO HAPPEN IN OTHER SETTINGS, SUCH AS SOIL, WHERE EXCESSIVE ORGANIC MATTER
DECOMPOSITION CAN LEAD TO OXYGEN DEPLETION IN THE SOIL PORE SPACES.
IN ADDITION, OXYGEN DEOXYGENATION CAN OCCUR IN CONFINED SPACES WITH POOR VENTILATION,
LIKE POORLY VENTILATED BUILDINGS OR UNDERGROUND MINES. ESSENTIALLY, ANY ENVIRONMENT
WHERE OXYGEN IS CONSUMED AT A RATE FASTER THAN IT CAN BE REPLENISHED CAN EXPERIENCE
DEOXYGENATION.

10. SEVERAL METHODS USED TO DEOXYGENATE WATER,
EITHER FOR INDUSTRIAL PROCESSES OR TO ADDRESS SPECIFIC
ENVIRONMENTAL ISSUES. SOME COMMON METHODS INCLUDE:
1. AERATION:
THIS INVOLVES INTRODUCING AIR OR OXYGEN INTO WATER TO INCREASE OXYGEN LEVELS. IN
SOME CASES, AERATION IS USED TO DEOXYGENATE WATER BY REMOVING DISSOLVED GASES
THROUGH BUBBLING OR AGITATION.
2. CHEMICAL DEOXYGENATION:
CHEMICALS SUCH AS SODIUM SULFITE OR SODIUM BISULFITE CAN BE ADDED TO WATER TO
CHEMICALLY REMOVE DISSOLVED OXYGEN. THESE CHEMICALS REACT WITH OXYGEN,
CONVERTING IT TO HARMLESS COMPOUNDS LIKE SULFATE.
3.BIOLOGICAL TREATMENT:
BIOLOGICAL PROCESSES, SUCH AS ANAEROBIC DIGESTION, CAN BE USED TO DEOXYGENATE
WATER BY PROMOTING THE GROWTH OF MICROORGANISMS THAT CONSUME OXYGEN. THIS IS
OFTEN USED IN WASTEWATER TREATMENT PLANTS.

11. 4. MEMBRANE TECHNOLOGIES:
MEMBRANE PROCESSES LIKE MEMBRANE CONTACTORS OR MEMBRANE DEGASIFIERS CAN BE USED TO
REMOVE DISSOLVED GASES, INCLUDING OXYGEN, FROM WATER BY PASSING IT THROUGH SELECTIVE
MEMBRANES.
5. VACUUM DEAERATION:
IN THIS METHOD, WATER IS EXPOSED TO A VACUUM TO REMOVE DISSOLVED GASES, INCLUDING
OXYGEN, BY LOWERING THE PRESSURE IN A CLOSED VESSEL.
6. CHEMICAL PRECIPITATION:
CHEMICALS LIKE FERROUS SULFATE OR SODIUM SULFITE CAN BE ADDED TO WATER TO CHEMICALLY
PRECIPITATE DISSOLVED OXYGEN AS INSOLUBLE COMPOUNDS, WHICH CAN THEN BE REMOVED BY
FILTRATION OR SETTLING.
THESE METHODS CAN BE USED INDIVIDUALLY OR IN COMBINATION, DEPENDING ON THE SPECIFIC
REQUIREMENTS AND CONSTRAINTS OF THE APPLICATION.

12. ENVIRONMENTAL CONSEQUENCES OF OXYGEN DEOXYGENATION IN
AQUATIC ECOSYSTEMS CAN BE SEVERE AND WIDE-RANGING:
1. FISH KILLS:
LOW OXYGEN LEVELS CAN LEAD TO SUFFOCATION AND DEATH OF FISH AND OTHER AQUATIC
ORGANISMS, RESULTING IN FISH KILLS AND DECLINES IN BIODIVERSITY.
2. HABITAT DEGRADATION:
OXYGEN-DEPLETED AREAS BECOME INHOSPITABLE TO MANY SPECIES, LEADING TO HABITAT
DEGRADATION AND LOSS OF CRITICAL HABITATS SUCH AS CORAL REEFS AND SEAGRASS BEDS.
3. ALTERED FOOD WEBS:
OXYGEN DEOXYGENATION CAN DISRUPT AQUATIC FOOD WEBS BY CAUSING SHIFTS IN SPECIES
COMPOSITION AND REDUCING POPULATIONS OF OXYGEN-SENSITIVE ORGANISMS, LEADING TO
IMBALANCES IN PREDATOR-PREY RELATIONSHIPS.
4. NUTRIENT CYCLING:
DEOXYGENATION AFFECTS NUTRIENT CYCLING PROCESSES, SUCH AS NITROGEN AND PHOSPHORUS
CYCLING, WHICH CAN LEAD TO FURTHER WATER QUALITY ISSUES LIKE EUTROPHICATION AND HARMFUL
ALGAL BLOOMS.

13. 5. ECONOMIC IMPACT:
DEAD ZONES AND FISH KILLS CAN HAVE SIGNIFICANT ECONOMIC IMPACTS ON FISHERIES, TOURISM,
AND RECREATIONAL ACTIVITIES, AFFECTING LIVELIHOODS AND LOCAL ECONOMIES DEPENDENT ON
HEALTHY AQUATIC ECOSYSTEMS.
6. LOSS OF ECOSYSTEM SERVICES:
OXYGEN DEOXYGENATION REDUCES THE ABILITY OF AQUATIC ECOSYSTEMS TO PROVIDE IMPORTANT
SERVICES SUCH AS WATER PURIFICATION, CARBON SEQUESTRATION, AND SHORELINE PROTECTION,
IMPACTING BOTH HUMAN AND ENVIRONMENTAL WELL-BEING. ADDRESSING OXYGEN DEOXYGENATION
REQUIRES EFFECTIVE MANAGEMENT STRATEGIES TO REDUCE NUTRIENT POLLUTION, IMPROVE WATER
QUALITY, AND PROTECT AND RESTORE CRITICAL AQUATIC HABITATS.

14. OXYGEN DEOXYGENATION CAN SIGNIFICANTLY AFFECT THE
EFFICIENCY OF AEROBIC WASTEWATER TREATMENT PROCESSES,
SUCH AS ACTIVATED SLUDGE OR AEROBIC BIOREACTORS, WHICH RELY ON OXYGEN-DEPENDENT MICROBIAL
ACTIVITY TO BREAK DOWN ORGANIC POLLUTANTS. HERE'S HOW OXYGEN DEOXYGENATION IMPACTS THEIR
EFFICIENCY:
1. REDUCED TREATMENT CAPACITY:
OXYGEN DEOXYGENATION LOWERS THE DISSOLVED OXYGEN LEVELS IN WASTEWATER, LIMITING THE AEROBIC
MICROBIAL ACTIVITY RESPONSIBLE FOR POLLUTANT DEGRADATION. THIS REDUCTION IN OXYGEN AVAILABILITY
CAN DECREASE THE TREATMENT CAPACITY OF AEROBIC SYSTEMS, LEADING TO LOWER POLLUTANT REMOVAL
RATES.
2. SLOWER REACTION RATES:
WITH LOWER OXYGEN LEVELS, MICROBIAL REACTIONS PROCEED AT SLOWER RATES, PROLONGING THE TIME
REQUIRED FOR WASTEWATER TREATMENT. THIS CAN RESULT IN LONGER HYDRAULIC RETENTION TIMES AND
REDUCED TREATMENT EFFICIENCY, ESPECIALLY DURING PERIODS OF HIGH ORGANIC LOADING OR LOW OXYGEN
AVAILABILITY.
3. INCREASED OPERATING COSTS:
TO MAINTAIN ADEQUATE OXYGEN LEVELS FOR MICROBIAL ACTIVITY, ADDITIONAL AERATION MAY BE REQUIRED,
LEADING TO INCREASED ENERGY CONSUMPTION AND OPERATING COSTS. OXYGEN DEOXYGENATION CAN ALSO
NECESSITATE THE USE OF SUPPLEMENTAL OXYGEN SOURCES, SUCH AS OXYGEN DIFFUSERS OR BLOWERS, TO
COMPENSATE FOR LOW DISSOLVED OXYGEN LEVELS.

15. 4. RISK OF PROCESS UPSETS:
OXYGEN DEOXYGENATION CAN DESTABILIZE AEROBIC WASTEWATER TREATMENT
PROCESSES, MAKING THEM MORE SUSCEPTIBLE TO PROCESS UPSETS AND FLUCTUATIONS
IN PERFORMANCE. THIS CAN RESULT IN EFFLUENT QUALITY VARIATIONS, SLUDGE
BULKING, OR FOAMING ISSUES, WHICH MAY REQUIRE CORRECTIVE ACTIONS AND
OPERATIONAL ADJUSTMENTS TO RESTORE PROCESS STABILITY.
5. FORMATION OF ANAEROBIC ZONES:
IN SEVERE CASES OF OXYGEN DEOXYGENATION, ANAEROBIC CONDITIONS MAY DEVELOP
WITHIN AEROBIC TREATMENT SYSTEMS, PROMOTING THE GROWTH OF ANAEROBIC
MICROORGANISMS AND THE PRODUCTION OF MALODOROUS COMPOUNDS LIKE
HYDROGEN SULFIDE AND METHANE. THIS CAN COMPROMISE TREATMENT EFFICIENCY
AND RESULT IN UNDESIRABLE ODORS AND GAS EMISSIONS. OVERALL, OXYGEN
DEOXYGENATION POSES CHALLENGES TO THE EFFICIENCY AND STABILITY OF AEROBIC
WASTEWATER TREATMENT PROCESSES,
HIGHLIGHTING THE IMPORTANCE OF MAINTAINING ADEQUATE OXYGEN LEVELS AND
IMPLEMENTING STRATEGIES TO MITIGATE THE IMPACTS OF OXYGEN DEPLETION.

16. SOME CUTTING EDGE RESEARCH EFFORTS FOCUSED ON
UNDERSTANDING AND MITIGATING OXYGEN DEOXYGENATION
IN THE ENVIRONMENT INCLUDE:
ADVANCING MONITORING TECHNOLOGIES:
MODELING OXYGEN DYNAMICS:
BIOGEOCHEMICAL CYCLING STUDIES:
ECOLOGICAL RESPONSES:
RESTORATION STRATEGIES:
POLICY AND MANAGEMENT SOLUTIONS:

17. THE RELATIONSHIP BETWEEN OXYGEN DEOXYGENATION AND CLIMATE
CHANGE, ESPECIALLY CONCERNING CARBON CYCLE DYNAMICS, IS
MULTIFACETED:
1. INCREASED CARBON RELEASE:
OXYGEN DEOXYGENATION CAN ACCELERATE THE RELEASE OF CARBON STORED IN SEDIMENTS AND
ORGANIC MATTER WITHIN AQUATIC ECOSYSTEMS. IN OXYGEN-DEPLETED CONDITIONS, MICROBIAL
PROCESSES SHIFT TOWARDS ANAEROBIC RESPIRATION, LEADING TO THE BREAKDOWN OF ORGANIC MATTER
AND THE RELEASE OF CARBON DIOXIDE (CO2) AND METHANE (CH4) INTO THE ATMOSPHERE. THIS
EXACERBATES CLIMATE CHANGE BY INCREASING GREENHOUSE GAS CONCENTRATIONS.
2. ALTERED CARBON SEQUESTRATION:
OXYGEN-DEPLETED ENVIRONMENTS MAY EXPERIENCE CHANGES IN PRIMARY PRODUCTION AND
ECOSYSTEM STRUCTURE, IMPACTING THE ABILITY OF ECOSYSTEMS TO SEQUESTER CARBON. REDUCED
OXYGEN LEVELS CAN AFFECT THE GROWTH AND DISTRIBUTION OF PRIMARY PRODUCERS LIKE
PHYTOPLANKTON AND MACROPHYTES, ALTERING THE RATES OF CARBON FIXATION AND STORAGE IN
BIOMASS AND SEDIMENTS.

18. 3. FEEDBACK LOOPS:
OXYGEN DEOXYGENATION CAN CREATE FEEDBACK LOOPS THAT AMPLIFY CLIMATE
CHANGE. FOR EXAMPLE, INCREASED NUTRIENT RUNOFF DUE TO AGRICULTURAL PRACTICES
AND URBANIZATION CAN LEAD TO EUTROPHICATION, WHICH EXACERBATES OXYGEN
DEPLETION. IN TURN, OXYGEN-DEPLETED CONDITIONS CAN STIMULATE THE RELEASE OF
NUTRIENTS FROM SEDIMENTS, FURTHER FUELING EUTROPHICATION AND CARBON RELEASE.
4. OCEAN ACIDIFICATION:
CLIMATE CHANGE-INDUCED OCEAN ACIDIFICATION, RESULTING FROM THE ABSORPTION OF
EXCESS ATMOSPHERIC CO2 BY SEAWATER, CAN EXACERBATE OXYGEN DEOXYGENATION.
ACIDIFICATION REDUCES THE SOLUBILITY OF OXYGEN IN SEAWATER, MAKING IT MORE
DIFFICULT FOR AQUATIC ORGANISMS TO OBTAIN OXYGEN AND EXACERBATING OXYGEN
STRESS IN MARINE ECOSYSTEMS.

19. OXYGEN DEOXYGENATION IS IMPORTANT IN WATER BECAUSE IT HELPS MAINTAIN WATER
QUALITY AND SUPPORTS VARIOUS INDUSTRIAL PROCESSES. REMOVING DISSOLVED
OXYGEN FROM WATER CAN PREVENT CORROSION IN PIPELINES AND MACHINERY, ENSURING
THE LONGEVITY OF INFRASTRUCTURE.
ADDITIONALLY, IN APPLICATIONS LIKE BREWING AND FOOD PROCESSING, REDUCING
OXYGEN LEVELS CAN IMPROVE PRODUCT QUALITY AND SHELF LIFE. IN ENVIRONMENTAL
CONTEXTS, DEOXYGENATION CAN ALSO BE CRUCIAL FOR MANAGING EUTROPHICATION
AND PREVENTING OXYGEN DEPLETION IN AQUATIC ECOSYSTEMS, WHICH CAN HARM FISH
AND OTHER AQUATIC LIFE.
OVERALL, OXYGEN DEOXYGENATION PLAYS A VITAL ROLE IN WATER TREATMENT,
INDUSTRIAL PROCESSES, AND ECOSYSTEM HEALTH.
IMPORTANT OF OXYGEN DEOXYGENATION

20. THANK YOU !!!
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