hygiene of water and water supplies 2010

8/8/2019 Hygiene of Water and Water Supplies 2010

1/129


2/129

Hygiene Of Water And Water

Supplies

Prof. Dr. SHERIF T. MOUBARAK


3/129

Hygienic Importance of

Water

Chemically pure wateriscomposed ofHydrogenand Oxygenin proportion of 2:1parts by volumei.e. H2O or 1:8 by weight.

Chemically pure waterdoesnotexist outsidethelaboratory (Solvent properties of water)


4/129

Properties of Water

Molecular Structure Wateris H2O, two atoms of

hydrogenattachedto oneatomof oxygen

Becausethe O atomhasa

greatermasstheelectronsspendmoretimenearitthannearthe H atoms

Thus, achargeasymmetryiscreatedsuchthatthe O end ofthemoleculehasanegativechargeandthe H endhasapositivecharge, thisiscalledadipole.


5/129

Properties of Water

Thischargeasymmetryresultsin weak bonding ofadjacentmolecules

Thenet resultisthat waterhassome unusualproperties

Itisaliquidat roomtemperature whenitshould bea gas


6/129

Hygienic Importance

The bodycanloose practicallyall ofits fatsand over ofits protein

whiletheloss of 1/10 ofits waterresultsinserious physicaldisorders.

Water represents from 55 to 75 % ofthe body weightdepending onage,sex andspecies oftheanimal.

Watermakes up to 65% ofthe wholeegg.


7/129

Water, helpsto regulate bodytemperature.

Wateristhekey forefficientdigestion, metabolismand faecalelimination.

Wateristhemostefficient way fordrug administrationto animalsandvaccinesto birds.


8/129

Sources of Water

Rain water

Surface water

Sea water

Ground water


9/129

The Hydrologic Cycle


10/129

Rain Water

Isthe origin ofall watersupplies.

TDS ranges from 20 to 50 mg/L.

During its fallit picks up CO2, dust,

microorganisms, particles ofcoal,iron, lime saltsandtraces of NaCl,sulphitesandsulphates.


11/129

Properties ofRain Water

Insipidtaste (Less Palatable).

Low TDS.

High Solventaction onmetals

especiallylead.


12/129

Surface Water

Is rain waterthathas fallen ontheearth, washeditssurfaceandhas

notyet penetrateditssurfacesufficientlydeep.

It forms watercourses formingRivers, Brooks , Ponds and Lakesetc.


13/129

Surface watershave one featureincommoni.e. Constantexposureto

contamination from varioussources.

So, from publichealth point of viewSurface watersareSuspicious


14/129

Sea Water

Unfit fordrinking. itcontains 35 g/L salts of which

27 g are NaCl.


15/129

Ground Water

Collection of rain waterand othersurface waters whichenterthesoil

andisnot returnedto thesurface.

Thecharacter ofthe ground water

depends on: 1- Thenature ofthesoillayers.

2- Thedepththrough which water

passes.


16/129

A body of rockthatissufficiently

permeableto conduct ground waterandto yieldeconomicallysignificantquantities of waterto

wellsandsprings

Aquifer


17/129

Aquifer (confined)--soil or rock below thelandsurfacethatissaturated with water. Therearelayers of

impermeablematerial bothaboveand below itanditisunder pressureso that whentheaquiferis penetrated bya well, the water will riseabovethetop oftheaquifer.

Aquifer (unconfined)--anaquifer whose upper watersurface (watertable) isatatmospheric pressure, andthusisableto riseand fall.


18/129

Well Geology


19/129


20/129

Methods of Obtaining

Ground Water

Wells I-Water bearing

strata:

ShallowDeepArtesian

II-Construction:DugDriven

Springs

Land

Fissure

Junction


21/129

Springs

Natural outlet ofthe ground wateratthesurface.


22/129

Springs

Fissurespring (Naturalartesian well)


23/129

Springs

Junctionspring (Geological fault)


24/129

Wells

Artificialmeans of gaining accesstoavailable

supply of ground water


25/129

Wells (according to the water

bearing strata)

Shallow Well: Doesnot passthroughimperviousstratum. (ithasno indicationofdepth)

Deep Well: Derives water below theimperviousstratum.

Artesian Well: Water risesdueto thepressure ofconfined waterintheaquifer(Hydrostatic pressure)


26/129

Wells (according to

construction)

DugorPit Well: excavated by picksandshovels (ormachinery), notmorethan 0.5 mindiameterandnotover 15 mindepth, hasalining orcasing fromcement or bricks.

Driven Well: a pipedriveninto awater bearing stratum (from 2.5 upto 90 cmindiameter), thelowersection ofthe pipeiscovered bya

well-screen.


27/129


28/129

Driven Well


29/129

Artesian Well


30/129

Protectyour well fromsurface runoff

Locateit upslope fromanimalholding areasandatleast 15-20 mfromthesepticsystem.

Do notspreadmanure, fertilizer oragriculturalchemicalsdirectlyupslope ofthe well.


31/129


32/129

Points to consider when

wells are constructed:

1-Wellsshould be farenough (10-30m)fromsources ofcontaminatione.g. animalhouses, farmyards, drains, cesspoolsandmanureheaps.

2-Theyshould reachthedeeperlayerstoavoidcontamination bysubsoil water.

3-Animpervious walllining should beconstructedto prevententrance ofcontaminated water fromthesides.


33/129

4-A sloping impervious guttershouldcarry wastewateraway.

5-Shallow wellsshould becovered withawatertightcoverto preventaerialpollution.

6-Surfacesoilshould besloped gentlyaway fromthe wellhead.

7-Wellscreensarenecessaryto preventsoil particles.


34/129

Sources Of WaterPollution

How Water IsP

olluted? Point Sources: only onesource for

whichspecific points ofentrycan be

identifiede.g. municipalandindustrialwastes.

Non-Point Sources: severalsources

whicharediffuseandcannot beeasilyidentifiedandlimitedto specific points ofentrye.g. agriculture wastesand generalrunoff.


35/129

Point Source Examples

Surface waterdischarges from

feedlots

Food processing plants

Agrichemical processing plants

Contamination fromchemicalspills Industrialdischarges


36/129

Nonpoint Source Examples

Nitrate pollution of groundwater fromfeedlots or fertilizers.

Return flows fromirrigation.

Pesticidesappliedto crops.

Generallyassociated withagriculture,forestry, mining, construction, andstormrunoff


37/129

Non-Point Sources


38/129


39/129

Sources Of WaterPollution

(How Water is Polluted?)

Natural

Agricultural

Wastewater


40/129

Natural Sources

Atmospheric

Dissolved Minerals (Leaching e.g.Ca &Mg)

Decay of Vegetation (Stagnantwater)

Storm Runoff (Erosion ofland)


41/129

Agricultural Sources

1-AnimalWastes (feedlots, manureheaps, excreta, urineand faecesPathogens

Drains of Slaughter Housesand Knackersyards. Throwing deadcarcassesin water.Burial ofdeadanimals beside watercourses.

2-Fertilizers Nitrogenand Phosphorus3-Pesticides4-Irrigation Return Flow Pesticides,

Nitrogen, Phosphorus


42/129

What are the Pathways by which Manure

Contaminates Water?

1. Surf ace runoff

UnsaturatedZone

WaterTable

Sand & GravelAquifer

Bedrock

2. Leaching to groundwater

3. Wellcasings

Septic TankSeptic Tank

PrivateWell

ManureManureStorageStorage

PrecipitationPrecipitation

1

2 2 23

4

4. Ammoniadeposition

5

5. Macropore flow 1-42


43/129

Wastewater

Municipal Sanitary Sewage

Bacteria, Chemicals, Organic Matter.

IndustrialWastewater Heavy

Metals.

Wastewater from Boats Aquatic

Life


44/129

Water Intended For Animal

Consumption Should Be:

1- Free fromCauses ofDiseases.

2-Palatable.

3- Sufficientin Quantity


45/129

Causes OfDiseases

Chemicals

1- Heavy Metals

2- Pesticides

3- NitratesandNitrites

PathogenicMicroorganisms

Bacteria, Viruses,Fungi

Parasitic Agents

Intestinal wormsandprotozoa


46/129

ChemicalsChemicalsChemicals

Heavy Metals


47/129

Lead

Seriouscumulative body poison.

Comes from: dissolution of old plumbing.

IndustrialAnd Mines Discharges

Smelters

Permissible Limit: 0.1 mg / L


48/129

Toxic Effects OfLead

Lead Encephalopathy

Gastroenteritis

Degeneration Of Peripheral Nerves


49/129

Cadmium

Highlytoxic GeneralizedCancerin Laboratory Animalsandcertainhumancancers (Kidneys).

200 ug / L istoxicto fish.

Itcomes from: Industrialdischargesordeterioration of galvanized pipes,batteries, paints.

Itis poorlyabsorbedin ruminants

Permissible Limit 0.005 mg / L


50/129

Arsenic

Cumulative poison Carcinogenic Aslittleas 100 mg Severe

poisoning in Humans. Sourcesin water:

Mineral DissolutionIndustrial Discharges,

Petroleum refining,Wood preservativesSome Insecticidesandherbicides


51/129

Permissible Limit 0.05 mg / L

Potential Health EffectsfromIngestionofWaterContainingArsenic

Skindamage

Circulatorysystemproblems

Increasedrisk ofcancer


52/129

EffectofArsenic inwateronhumanbeings(casestudyofRahim YarKhanarea)


53/129

EffectofArsenic presenceinwateronskinofkids


54/129

Copper

Coppersaltsare usedto control biologicalgrowthsin watersupplysystems.

Sources:- Corrosion ofcopperalloysin pipe.

- Rustycoppercontainers- Wood preservatives

Sheep ismoresensitiveto copperthanotherlivestock.

Effects: Gastrointestinalirritation, offtaste,blue greenstaining of plumbings.

Permissiblelimit 1mg / L


55/129

Chemicals

PesticidesHow theyenter water ?

Soil RunoffRainfallDirect Application

AccidentalspillsFaulty wastedisposal


56/129


57/129

Pesticides

Chlorinated Hydrocarbonshavelonghalflifeso, moredangerousandtoxicto aquaticlifethan organophosphoruscompoundsandCarbamates.

0.001 mg / L


58/129

Organochlorine

insecticides

DDT and others e.g.methoxychlor,aldrin,dieldrin,

endrin,heptachlor, kepone,lindane,chlordane

DDT bannedin 1973

DDT


59/129

DDT

Cl C

H

CCl3

Organochlorineinsecticide 1945 controlofmosquitoes Effectivebutverypersistent Verysolubleinfat Damagedbirdeggs


60/129

Organochlorine (DDT)

Problems

Highly persistent in environment / animals stable, not brokendown byanimal

enzymes, soilmicrobes, orsunlighte.g. structurestreated withcyclodienes fortermite

controlstill protectedafter 50 yrs

Highly insoluble in water

foundexclusivelyinsediments

notexcreted whenconsumed

Highly soluble in fatty tissue

ends up being storedinanimaltissues


61/129

Organophosphate

insecticides

Malathion,parathion,guthion,diazinon


62/129

P th id


63/129

Pyrethroids

Synthetic PyrethroidsBasedonnaturallyoccurringpyrethrums

from chrysanthemumflowers

Discoveredby Chinesein100ADFirst commercialusein1800s

Firstsynthetic pyrethroidsin1980

Relativelylowanimaltoxicity

EffectsmovementofcellularNa+ (sodium)Use Growingrapidly


64/129

Organophosphates &Carbamates- excessacetylcholine

Oganochlorines & Pyrethroids

- Enzymes,axonalmembranes(Na+, K+, Ca++, Cl-)


65/129

Effects OfPesticides

TasteOrganolepticchanges

Odour

Toxicity: (endocrinedisruption) Accumulationin fish (biomagnifications)

- Affectskinandm.m. e.g. Pyrethroids

N.B. Conventional watertreatmentmethodsdo notremoveall pesticides residues.


66/129

Ecological effects of

pesticides

Bioconcentration: Themovement ofachemical fromthesurrounding mediuminto an organism. (DDT islipophilic)

Biomagnification: Theincreasingconcentration ofachemicalas food

energyistransformed withinthe foodchain. Veryhighconcentrationscan beobservedintop predators, including man.


67/129


68/129

Death ofthe organism.

Cancers, tumoursandlesions on fishandanimals.

Reproductiveinhibition or failure.

Suppression ofimmunesystem.

Disruption ofendocrine (hormonal) system.

Cellularand DNA damage.

Ecologicaleffectsofpesticides


69/129


70/129

Chemicals

NITR

AT

ESN

O3

__

Sources:

Decaying animal or plant proteins Animalmetabolic wastese.g. urea

andammonia. (on-lotsepticsystems)

Nitrogen fertilizers.Runoff

Soilhighinnitrogen


71/129


72/129


73/129

Nitratesarehighly watersolubleso,Nitratesareeasilyleached away

(penetrate gradually) to the ground

water.

The Nitrateionitselfisnot

particularlytoxic, butnitriteisthereduced form ofnitrateishighlytoxic. Why ?


74/129

Hb-Fe++

(Haemoglobin)

NitriteNitriteNitrite

Hb-Fe+++ (Methaemoglobin)(Cantacceptmolecular oxygen)


75/129


76/129

The Haemoglobin Molecule


77/129

Excessnitrateisharmfulto:

Monogastrics:

Young:

Human

Chickens

Pigs

HorsesHorsesHorses

Adults:

Horses (Horses (Horses (CaecumCaecumCaecum)))

Ruminants:

Young:

SheepSheepSheep

CattleCattleCattle

Adults:

SheepSheepSheep

CattleCattleCattle

Symptoms Of Nitrate And


78/129

Symptoms OfNitrate And

Nitrite Poisoning In

Animals

- Bluish or brownishdiscoloring ofnonpigmentedareas (aroundthemouth

andeyes) ormucousmembranes.- Sluggish, staggering gait.

- Rapidheartbeat.

- Frequent urination.

- Labored breathing followed bycollapse.

- Inseverecases, convulsionandcoma


79/129

Permissible Limit Of Nitrates InDrinking Water

10 mg/L nitrate-nitrogen (NO3-N)

=

44.3 mg/L nitrate (NO3-)


80/129


81/129

Evaluating Risks ForWaterborneInfectious Agents

Examination foreachtype ofpathogensis:

Long (TimeConsuming)

Complex

Expensive


82/129

Water Borne Diseases


83/129

The Concept Of Indicator

Organisms

Occurextensivelyinhumanandanimalwastes whether ornotthe person (oranimal) suffers froma water borne

disease. Examples:

Coliform group

Clostridium perfringens Klebsiellaspecies

Pseudomonasspecies

Faecalstreptococci

Desirable characteristics of


84/129

Desirablecharacteristics ofIndicator Organisms

(Ideal Indicators) HarmlessHarmlessHarmless PresentPresentPresent whetherthe pathogenis present

ornot.

Presentinhighernumbershighernumbershighernumbers thanthepathogen.

EasyEasyEasy andquickquickquick to identify.

Easyto enumerateenumerateenumerate. SurviveSurviveSurvive unfavourableconditionslongerlongerlonger

thanthe pathogen.


85/129

The Coliform Group

Coliform On Endo Agar

C lif C l i


86/129

Coliform Colonies on

Membrane Filter


87/129

D i ki W t


88/129

Drinking Water

Requirements


89/129

Average Daily Water

Consumption

Milking Cow 50 L Milking Cow + service 130 L Calves 8 25 L

Sheep 5 8 L Goat 3 5 L Broilers (6 weeks) 15 L (100 birds) Layers (90 % production) 25 L (100

birds).


90/129

Improvement Of Water


91/129

Improvement Of Water

RemovalofSourcesofPollution

S t (S lf)


92/129

Spontaneous (Self)

Purification

Theability ofthe riverto get rid ofvarious pollutants byconverting

themto Carbondioxide, waterandother gasesthroughtheaction ofbacteriaand other organismsthat

consume organicmatter.


93/129

Spontaneous Purification

Pathogenicmicroorganisms failtogrow and reproducein waterduetothe following factors:

Aeration Increaseddissolvedoxygen.

Sunlight Increases photosynthesis.

S

edimenta

tion turbidity reduced. Agitation destruction ofmicroorganisms.


94/129

Spontaneous Purification

Oxidation: organicmatterisoxidized byaerobicmicroorganisms.

Reduction: dueto theaction ofanaerobic bacteriainthe bottom.

Dilution: infectivematerials becomediluted.

Starvation: occurs finally.


95/129

Coagulation & Flocculation

Coagulation: Thedestabilization ofcolloidal particles (1umto 1 nm) bytheaddition ofachemicalcalledCoagulant e.g. trivalentcationse.g.aluminiumsulphate

AL2

(SO4)

3.14 H

2O


96/129


Flocculation: istheagglomerationofdestabilized particlesintomicroflocand bulky floccules whichcan besettled.


97/129


98/129


Positivelychargedcoagulantsattracttonegativelycharged particlesduetoelectricity.


99/129


Neutrallycharged particlesattractdueto VanderWaals forces.


100/129


Particlesandcoagulantsjointogetherinto floc.


101/129

Settling

Flocs, thathave been formed, areseparated from waterin gravitysettling tanks.

Sludge


102/129

Filtration

Passing waterthrougha bed ofcarefullyselectedand gradedsandand gravel,usuallyinadownwarddirection.

Suspended particlesare removedandaccumulated betweenthesand grainsuntiltheyarelargely filled.

Thenthe filtermust becleaned by

reversing the flow of waterthroughthebed. (Backwashing)


103/129

Sand Filters

Slow Sand Filter

Rapid Sand Filter


104/129


105/129

Slow Sand Filter

Removal of Hardness


106/129

Removal of Hardness

(Water Softening)

Hard Water

Water which formsalather withdifficultywithsoap.


107/129

Water Hardness

Hardness of waterisduetoCalcium andMagnesiumsaltsinsolution.


108/129

Water Hardness

Soap containssalts of fattyacids

i.e. Sodium or Potassium Stearates(Soluble).

Inthe presence ofhard water, Caand Mg ions replacesodium orpotassiumandaninsoluble curdisformed (Caand Mg stearates)


109/129

Water Hardness

(C15H31COO)2 Na

(C17H35COO)2 K

Ca Mg


110/129

Types Of Hardness

Temporary (Carbonate)Hardness

Permanent Hardness

Total Hardness

Temporary (Carbonate)


111/129

Temporary (Carbonate)

Hardness

Dueto Bicarbonate ofCaand Mg

Boiling

CO2 & Carbonates ofCaand Mg

Ca (HCO3) 2 CaCO3 + CO2 + H2O Mg (HCO3) 2 MgCO3 + CO2 + H2O


112/129

Permanent Hardness

Sulphates

Chlorides Ca & Mg

Nitrate

It Cannotberemovedbyboiling


113/129

Total Hardness

Temporary Hardness

+ Total Hardness

Permanent Hardness

Totalhardness: Isthetotalconc. of

theions ofCa++, Mg++ and Fe++

in waterexpressedinmg/L

Hygienic & Economic


114/129

Hygienic & Economic

Significance Of Hardness

Wastage of Soap. Wearing out of Fabrics (Ca & Mg salts

make fibres brittle). Scale (Fur) formation onsurface of

heaters wastage ofenergy. Corrosion of boilers (Boilerscales) Excess Mg badtaste. Hard watermayaffectsomeinsecticides,

disinfectantsandlive vaccines. Verysoft waterisalso undesirable

(corrosiveto pipesandtanks)

W t S ft i


115/129

Water Softening

Boiling:

Only fortemporaryhardness. Uneconomic.

Notallcarbonates ofCa & Mg

are precipitated.

W t S ft i


116/129

Water Softening

LimeandLime-SodaSoftening:

1- Ca (HCO3) + Ca (OH) 2 2 CaCO3 + 2H2O

2- Mg (HCO3) + 2 Ca (OH) 2 2 CaCO3 + Mg (OH) 2 + 2 H2O

3- MgSO4 + Ca (OH) 2 Mg (OH) 2 + CaSO4

Stillcausing hardness

4- CaSO4 + Na2 CO3 CaCO3 + Na2 SO4

W t S ft i


117/129

Water Softening

Base Exchange:

Using naturally occurring orsyntheticcompoundshaving ionexchange properties.

Thesecompoundsareknownas:zeolites. E.g. Sodiumaluminiumsilicate ( Permutit).

B E h


118/129

Base Exchange

Ca(HCO3) + Na2 Z CaZ + NaHCO3

MgSO4 + Na2 Z Mg Z + Na2SO4

Regeneration:

CaZ + 2 NaCl Na2 Z + CaCl2

Water SoftenerWater Softener


119/129

RESIN(Sodium

OrPotassium)

Raw Water

(Sodium or Potassium)

Calcium &

MagnesiumAnd otherMultivalent

cations

TreatedWater

Ion Exchange: Sodium forCalcium & Magnesium

Recharge with BrineRecharge with Brine


120/129

gg

RESIN(Calcium

&

Magnesium)

WasteWater

(Sodium or Potassium)

Calcium & Magnesiumandothermultivalentcations

Brine

Reverse OsmosisReverse Osmosis


121/129

Force waterthroughmembraneForce waterthroughmembrane

RemovesmanycontaminantsRemovesmanycontaminants

Di i f ti Of W t


122/129

Disinfection Of Water

Chlorine Gas:0.25 2mg/L

Cl2 +H2O HOCl + HCl HOCl H+ + OCL-

HOCl Hypochlorusacidaccomplishthedisinfection.

OdourandColour removal. Iron removal.

Di i f ti Of W t


123/129


Hypochlorination: The oldestmethod using chlorinated

lime (Bleaching Powder).

Chlorinatedlimehas beendisplacedbyCalcium HypochloriteCa (OCl)2.4H2OChlorinecontent 70%.

Sodium HypochloriteNaOCLChlorinecontent 12-15%.

DisinfectionDisinfection


124/129

DisinfectionDisinfectionShockChlorinationShockChlorination

Maywork forsmallnumbersofcoliformbacteria.Shouldbe conductedafterallwellrepairs,flooding,orproblemswithelevatedbacterial counts. Aftershockdisinfection retestingfortotal coliform,standardplate

count, andnuisancebacteriamaybeneed.



125/129


OtherChlorine Compounds:

Chlorine DioxideClO2

Very usefulintasteand odourremoval besidesdisinfection.



126/129


Iodineand Iodine Compounds: Iodophores

Iodine + Phosphoricacid + Carrier Hypoiodusacid & molecular Iodinedoes

not react withammonia or organicnitrogencompounds.

Veryeffective, may beaddedto drinkingwatertill faintyellow colour (10 12 ppm)

i.e. Selfindicator. Some physiologicaleffect uponthyroid

activity.



127/129


Potassium Permanganate:

A dark purplesalt of permanganicacid.

May beaddedto drinking watertillfaint pinkcolour.

(1:10.000 1:150.000)

Also used for Iron, Manganese,Tasteand Odour removal.


The Use Of Ozone


128/129

The Use Of Ozone

(Ozonation)



129/129


UltravioletLight (253nm)

hygiene of water and water supplies 2010

Documents