water hardness & water hardness & special treatment special treatment

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Water hardness &Water hardness &Special treatmentSpecial treatment

Introduction Introduction

Water described as "hard" is high in Water described as "hard" is high in dissolved minerals, specifically calcium and dissolved minerals, specifically calcium and magnesium. Hard water is not a health risk, magnesium. Hard water is not a health risk, but a nuisance because of mineral buildup but a nuisance because of mineral buildup on fixtures and poor soap and/or detergent on fixtures and poor soap and/or detergent performance. performance.

Water hardnessWater hardness

One of the factors that establishes One of the factors that establishes the quality of a water supply is its the quality of a water supply is its degree of hardness. degree of hardness.

Hardness is defined as calcium Hardness is defined as calcium and magnesium ion content. and magnesium ion content.

HARDNESS OF WATER:HARDNESS OF WATER:

Hardness may be defined as a soap destroying Hardness may be defined as a soap destroying power of water. It is temporary when there is power of water. It is temporary when there is presence of calcium bicarbonate and presence of calcium bicarbonate and magnesium bicarbonate & permanent when it magnesium bicarbonate & permanent when it is containing calcium sulphate chlorides and is containing calcium sulphate chlorides and nitrates.nitrates.

Water hardnessWater hardness

Water hardness is usually noticed because of Water hardness is usually noticed because of difficulty in lathering soap and the formation difficulty in lathering soap and the formation of a scum in the bathtub.of a scum in the bathtub.

Ca and Mg form insoluble salts with soaps Ca and Mg form insoluble salts with soaps causing precipitation of the soap scum.causing precipitation of the soap scum.

What is soft water?What is soft water?

Soft water produces a rich lather with ordinary Soft water produces a rich lather with ordinary soap. The pure rain water, spring water, etc is soap. The pure rain water, spring water, etc is soft is soft water, since it contains less amount soft is soft water, since it contains less amount of dissolved salts in it.of dissolved salts in it.

Cause of water hardness Cause of water hardness Most hardness is caused by carbonate mineral Most hardness is caused by carbonate mineral deposits, hardness is usually reported as parts per million deposits, hardness is usually reported as parts per million

(ppm) of calcium carbonate (by weight). (ppm) of calcium carbonate (by weight). A water supply with a hardness of 100 ppm contains the A water supply with a hardness of 100 ppm contains the

equivalent of 100 g of CaCO3 in 1 million g of water or 0.1 g equivalent of 100 g of CaCO3 in 1 million g of water or 0.1 g in 1 L of water .in 1 L of water .

Effects of water hardnessEffects of water hardness Hard water interferes with almost every cleaning task from laundering and Hard water interferes with almost every cleaning task from laundering and

dishwashing to bathing and personal grooming.dishwashing to bathing and personal grooming. Clothes laundered in hard water may look dingy and feel harsh and Clothes laundered in hard water may look dingy and feel harsh and

scratchy.scratchy. Dishes and glasses may be spotted when dry.Dishes and glasses may be spotted when dry. There is soap wastage. There is soap wastage.

Effects on bodyEffects on body

Hair feels dry and stickyHair feels dry and sticky Hair is resistant to color Hair is resistant to color Dandruff or eczema of the scalp Dandruff or eczema of the scalp Dry, flaky skin Dry, flaky skin Thinning hair Thinning hair Colors fading too quickly Colors fading too quickly Perms appear to fall out Perms appear to fall out Discoloration or darkening of hair Discoloration or darkening of hair Hair lacks body and shine Hair lacks body and shine

Effects of water hardnessEffects of water hardness

Another effect of hard water is “boiler scale”. Another effect of hard water is “boiler scale”. When hard water comes into contact with When hard water comes into contact with dissolved carbonates, a precipitate of insoluble dissolved carbonates, a precipitate of insoluble calcium carbonate forms.calcium carbonate forms.

This “scale” can build up on the inside of This “scale” can build up on the inside of water pipes to such a degree that the pipes water pipes to such a degree that the pipes become almost completely blocked.become almost completely blocked.

Types of hardnessTypes of hardness

Hard water is of two types based on the types Hard water is of two types based on the types of salts dissolved in it:-of salts dissolved in it:-

Temporary hard water: - Contains Calcium Temporary hard water: - Contains Calcium and Magnesium Bicarbonates.and Magnesium Bicarbonates.

Permanent hard water: - Contains Calcium and Permanent hard water: - Contains Calcium and Magnesium Chlorides and Sulphates.Magnesium Chlorides and Sulphates.

Removal of hardness of waterRemoval of hardness of water

Temporary hardness can be removed by boiling the Temporary hardness can be removed by boiling the water and then filtering it. The Calcium and water and then filtering it. The Calcium and magnesium bicarbonates present in temporarily hard magnesium bicarbonates present in temporarily hard water form insoluble precipitates on boiling the water form insoluble precipitates on boiling the water. The Carbon dioxide present in bicarbonates is water. The Carbon dioxide present in bicarbonates is also removed during boiling. Ca(HCOalso removed during boiling. Ca(HCO33))22 → CaCO → CaCO33↓ ↓

+ CO+ CO22 + H + H22O. In this reaction, CaCOO. In this reaction, CaCO33 is the insoluble is the insoluble

precipitate which can be filtered out. COprecipitate which can be filtered out. CO22 gas is gas is

evolved, and soft Hevolved, and soft H22O is left behindO is left behind

Permanent hardnessPermanent hardness

Permanent hardness can be removed by addition of Permanent hardness can be removed by addition of washing soda (Nawashing soda (Na22COCO33) in water. Reaction: ) in water. Reaction:

NaNa22COCO33 + CaSO + CaSO44 (this is present in hard water) → (this is present in hard water) →

CaCOCaCO33↓ + Na↓ + Na22SOSO44

In the above reaction, the dissolved salt CaSOIn the above reaction, the dissolved salt CaSO44 reacts reacts

with washing soda to form a precipitate and evolve with washing soda to form a precipitate and evolve Carbon dioxide (COCarbon dioxide (CO22). The insoluble precipitate ). The insoluble precipitate

CaCOCaCO33 is easily removed by filtering. is easily removed by filtering.

Other methods:Other methods:

By addition of ,By addition of , -lime,-lime, -sodium carbonate-sodium carbonate - permuted (which is a complex compound of - permuted (which is a complex compound of

sodium, aluminium and silica.sodium, aluminium and silica.

Fluoridation of WaterFluoridation of Water

Deficiency of fluorine in drinking water is Deficiency of fluorine in drinking water is associated with dental caries, and excess with associated with dental caries, and excess with dental and skeletal flouorosis. dental and skeletal flouorosis.

The term fluoridation has been given to the The term fluoridation has been given to the process of supplementing the natural fluoride process of supplementing the natural fluoride content of potable water to the point of content of potable water to the point of optimum concentration. optimum concentration.

DefluoridationDefluoridation

In some geographic areas, water may contain a In some geographic areas, water may contain a high level of fluoride. Water is defluoridated high level of fluoride. Water is defluoridated by phosphate to reduce fluorides to optimum by phosphate to reduce fluorides to optimum levels levels

Selection of source of waterSelection of source of water

In selecting a source attention must be given to In selecting a source attention must be given to possible future developments that may possible future developments that may influence the continued suitability of the influence the continued suitability of the source. Other consideration include:source. Other consideration include: QuantityQuantity QualityQuality ProtectionProtection FeasibilityFeasibility TreatabilityTreatability

Swimming Pool SanitationSwimming Pool Sanitation

Swimming pool water is exposed to:Swimming pool water is exposed to: Feacal contamination Feacal contamination Organisms from skin and nasoharynxOrganisms from skin and nasoharynx

Sanitation MeasuresSanitation Measures

2.2 sq. m. is required per swimmer. All 2.2 sq. m. is required per swimmer. All swimmers are directed to empty bladder and swimmers are directed to empty bladder and use the toilet before swimming. A cleansing use the toilet before swimming. A cleansing shower bath should be taken.shower bath should be taken.

Filtration of waterFiltration of water ChlorinationChlorination

A continuous maintenance of 1 mg/liter of free A continuous maintenance of 1 mg/liter of free chlorine residual provides adequate protection. chlorine residual provides adequate protection.