World Water CrisisWorld Water Crisis ” ‘Water, water everywhere’ but what’s a brother gotta do to get a drink around ” ‘Water, water everywhere’ but what’s a brother gotta do to get a drink around

here?”here?”

Joel ThomasJoel ThomasCBE 555CBE 555

November 27, 2007November 27, 2007

Updated: Joel Thomas (F07)Updated: Joel Thomas (F07)Original: Christie Dosch (F05)Original: Christie Dosch (F05)

Contents of the CrisisContents of the Crisis

• Availability/SafetyAvailability/Safety

• SanitationSanitation

• DesalinationDesalination

• Other factorsOther factors– ContaminationContamination

Availability/SafetyAvailability/Safety

Water BreakdownWater Breakdown• 70% of Earth is H70% of Earth is H22OO

• 3% of H3% of H22O is O is freshwaterfreshwater

• Of freshwaterOf freshwater– 79% is glacial79% is glacial– 20% is groundwater20% is groundwater– 1% is surface water1% is surface water

• Of surface waterOf surface water– 52% is lakes52% is lakes– 38% is soil Moisture38% is soil Moisture– 8% is atmospheric vapor8% is atmospheric vapor– 1% in living organisms1% in living organisms– 1% is rivers1% is rivers

Percent of Population with Percent of Population with Access to Safe Drinking Water Access to Safe Drinking Water by Country, 2000by Country, 2000

Percent of Total Disease Percent of Total Disease Burden Caused by Unsafe Burden Caused by Unsafe Water by Country, 2000Water by Country, 2000

Renewable Freshwater Supply Renewable Freshwater Supply by Country*, 2000by Country*, 2000

*m3 per person per year

ScarcityScarcity

• Middle EastMiddle East– ““Many of the wars of this [20th] century Many of the wars of this [20th] century

were about oil, but the wars of the next were about oil, but the wars of the next century will be about water” - World Bank century will be about water” - World Bank Vice President Ismail SerageldinVice President Ismail Serageldin

– Hebron, Palestine limited households to Hebron, Palestine limited households to running water twice a monthrunning water twice a month

– Egypt will require an extra 20 million mEgypt will require an extra 20 million m33 to to meet the needs of the growing populationmeet the needs of the growing population

QualityQuality

• Only 60% of population of Africa has Only 60% of population of Africa has access to safe drinking wateraccess to safe drinking water– In largest cities, < 10% have sewer In largest cities, < 10% have sewer

connectionsconnections• Increased preference for/reliance on well Increased preference for/reliance on well

waterwater

• 2.3 billion people world wide suffer 2.3 billion people world wide suffer from diseases linked to dirty waterfrom diseases linked to dirty water– ContaminationsContaminations

•Biological – Poor SanitationBiological – Poor Sanitation•Chemical/Mineral – Further Study of Arsenic in Chemical/Mineral – Further Study of Arsenic in

BangladeshBangladesh

TreatmentTreatment

Sewage TreatmentSewage Treatment

Sewage TreatmentSewage Treatment

• PreliminaryPreliminary– Filter/screen to remove solids and gritFilter/screen to remove solids and grit– Solids and grit are washed and land-Solids and grit are washed and land-

filledfilled

Sewage TreatmentSewage Treatment

Sewage TreatmentSewage Treatment

• PrimaryPrimary– Settling tanks (clarifiers) to remove Settling tanks (clarifiers) to remove

remaining solidsremaining solids– Produces “sludge” containing 70% of Produces “sludge” containing 70% of

initial solidsinitial solids•Sludge treated by digestionSludge treated by digestion

– Heat bacteria to optimal conditionsHeat bacteria to optimal conditions– Produces methane Produces methane

May be used as fuelMay be used as fuel– Remaining solids are cooled and used as fertilizerRemaining solids are cooled and used as fertilizer

Sewage TreatmentSewage Treatment

Sewage TreatmentSewage Treatment

• SecondarySecondary– Percolating filtersPercolating filters– Aeration tanksAeration tanks

– Biological waste from either treatment is Biological waste from either treatment is settled outsettled out

Sewage TreatmentSewage Treatment

Sewage TreatmentSewage Treatment

• TertiaryTertiary– Kill bacteriaKill bacteria

•Disinfect using chlorine/bleachDisinfect using chlorine/bleach– Dechlorinate using sodium bisulfite or similar Dechlorinate using sodium bisulfite or similar

compoundcompound

•Reed beds, sand filters, grass plots Reed beds, sand filters, grass plots

•UV lightUV light

Assessing PotabilityAssessing Potability

• Biochemical Oxygen Demand (BOD)Biochemical Oxygen Demand (BOD)– Amount of OAmount of O22 required by bacteria to required by bacteria to

oxidize organic material in 5 daysoxidize organic material in 5 days– Drinking water < 1ppmDrinking water < 1ppm– Raw sewage >> 100ppmRaw sewage >> 100ppm

DesalinationDesalination

DesalinationDesalination

• 7500 plants world wide7500 plants world wide– 60% in Middle East 60% in Middle East

•Saudi Arabia produces 128 million gallons Saudi Arabia produces 128 million gallons per dayper day

– 12% in Americas12% in Americas•Florida and CaribbeanFlorida and Caribbean

Desalination ProcessDesalination Process

• Requires pre-treatmentRequires pre-treatment– ChlorinationChlorination– OzoneOzone– UV lightUV light– Stripping or scrubbing to remove Cl or Stripping or scrubbing to remove Cl or

OO33

Desalination ProcessesDesalination Processes

• 1-50 ppm solids1-50 ppm solids

• Phase separationPhase separation– Multiple Effect Multiple Effect

DistillationDistillation• Sometimes paired with Sometimes paired with

membranemembrane

– Multiple Stage FlashMultiple Stage Flash• Flash at successively Flash at successively

lower pressureslower pressures

– Mechanical Vapor Mechanical Vapor CompressionCompression

• Higher Concentrations Higher Concentrations

• Mechanical separationMechanical separation– Reverse OsmosisReverse Osmosis– Electrodialysis ReversalElectrodialysis Reversal

• ~98% salt removal ~98% salt removal

• Used if ~2% of initial Used if ~2% of initial salt content allowablesalt content allowable

• Otherwise, further Otherwise, further separation requiredseparation required

Desalination EfficiencyDesalination Efficiency

• City of Santa Barbara Desalination PlantCity of Santa Barbara Desalination Plant– 8.2 MGD of brine8.2 MGD of brine

•At 1.8 X the Salinity of SeawaterAt 1.8 X the Salinity of Seawater

– 6.7 MGD product6.7 MGD product– 1.7 MGD filter brine1.7 MGD filter brine– 1.7-5.1 cubic yards/day of solids1.7-5.1 cubic yards/day of solids

– ~40 percent water recovery!!!~40 percent water recovery!!!

Why aren’t these used in Why aren’t these used in Africa?Africa?

• Lack of education Lack of education

• Lack of technologyLack of technology

• Lack of stable governmentLack of stable government

• Lack of fundsLack of funds

Other FactorsOther Factors

• PollutionPollution– Water contaminated with toxic materialsWater contaminated with toxic materials– Acid rainAcid rain– Eutrophication – disrupts ecosystemEutrophication – disrupts ecosystem

•E.g. Phosphorus, Nitrogen from fertilizerE.g. Phosphorus, Nitrogen from fertilizer

• Global warmingGlobal warming– Redistribution of waterRedistribution of water

•Glaciers meltingGlaciers melting

•Aquifers depletingAquifers depleting

ContaminationContamination

Source of ContaminantsSource of Contaminants

• Underground injections wellsUnderground injections wells

• LandfillsLandfills

• Runoff from roads/agricultureRunoff from roads/agriculture

• Leaks/spills in chemical storage or Leaks/spills in chemical storage or transportation (including septic, transportation (including septic, petroleum)petroleum)– 1 L of gas contaminates 1 Million L of 1 L of gas contaminates 1 Million L of

groundwatergroundwater

Arsenic ContaminationArsenic Contamination

• IndiaIndia– Bengal and Bengal and

Bangladesh Bangladesh (Ganges River area)(Ganges River area)

– As high as 1.8ppm As high as 1.8ppm (EPA limit is 10ppb)(EPA limit is 10ppb)

– ~200,000 people ~200,000 people dead from As dead from As poisoningpoisoning

Arsenic DecontaminationArsenic Decontamination

• RemovalRemoval– Adsorption with Adsorption with

ferric oxide ferric oxide compoundcompound

– ppt with iron saltsppt with iron salts– NanofiltrationNanofiltration

– MnOMnO22

– CoagulationCoagulation

• ProblemsProblems– Removal is expensiveRemoval is expensive– Detection is difficultDetection is difficult

• Field tests only detect Field tests only detect above 0.05mg/L (the above 0.05mg/L (the upper limit)upper limit)

– Technology is not Technology is not readily availablereadily available• Expensive EquipmentExpensive Equipment

• Extensive TrainingExtensive Training

ReferencesReferences

• http://www.world-wide-water.com/ - water treatment technical info/guide - water treatment technical info/guide• http://www.who.int/mediacentre/factsheets/fs210/en/ - World Health Org.; - World Health Org.;

Bangladesh infoBangladesh info• http://www.wateryear2003.org/en/ev.php-http://www.wateryear2003.org/en/ev.php-

URL_ID=4874&URL_DO=DO_TOPIC&URL_SECTION=201.html – African SituationURL_ID=4874&URL_DO=DO_TOPIC&URL_SECTION=201.html – African Situation• http://www.umich.edu/~gs265/society/waterpollution.htm - water distribution, http://www.umich.edu/~gs265/society/waterpollution.htm - water distribution,

usage, & pollutionusage, & pollution• http://ohioline.osu.edu/aex-fact/0768.html - treatment principles, regulations, & http://ohioline.osu.edu/aex-fact/0768.html - treatment principles, regulations, &

diagramdiagram• http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SewageTreatment.html http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SewageTreatment.html

-Sewage treatment principles-Sewage treatment principles• http://www.coastal.ca.gov/desalrpt/dchap1.html - Seawater Desalinationhttp://www.coastal.ca.gov/desalrpt/dchap1.html - Seawater Desalination• http://www.nature.com/nature/focus/water/index.html - Global Water Crisis http://www.nature.com/nature/focus/water/index.html - Global Water Crisis

ArticlesArticles• http://news.nationalgeographic.com/news/2000/07/0714_water.html - Water and http://news.nationalgeographic.com/news/2000/07/0714_water.html - Water and

Peace in the Middle EastPeace in the Middle East• http://answers.google.com/answers/threadview?id=34014 – Further Resources http://answers.google.com/answers/threadview?id=34014 – Further Resources

for Desalination (specifically charitable)for Desalination (specifically charitable)• http://www.mwra.state.ma.us/03sewer/html/sewditp.htm - Detailed WW http://www.mwra.state.ma.us/03sewer/html/sewditp.htm - Detailed WW

TreatmentTreatment

Seawater Composition

Element % by mass Component molality (mol/kg)O 85.84 H2O 53.6H 10.82 Cl- 0.546Cl 1.94 Na+ 0.469Na 1.08 Mg2+ 0.0528Mg 0.1292 SO4,2- 0.0282S 0.091 Ca2+ 0.0103

Ca 0.04 K+ 0.0102K 0.04 C inorganic 0.00206Br 0.0067 Br- 0.000844C 0.0028 B total 0.000416

Au less Sr2+ 0.000091 F- 0.000068