◼️Physical characteristics of drinking water

🔻 Temperature (10 ℃ to 20 ℃)

👉 Temperature should not be less than 10 ℃.

👉 Higher the temperature lower will be solubility.

🔻 Colour (5 ppm - 10 ppm)

👉 It is measured by Tintometer

👉 It is measured on Platinum Cobalt Scale

🔻 Turbidity (5 ppm - 10 ppm)

Turbidity is the measure of resistance to the passage of light through water

👉 It is measured on Silica scale

👉 It is measured by turbidity meter.

♦️ Taste and Odour (< 3TON)

👉 Odour is expressed in terms of TON (Threshold odour Number)

👉 Odour is measured by an apparatus called Osmoscope

👉 It is tested normally at 20℃ to 25℃

🔻 Specific Conductivity

👉 To know dissolved salt content. Determined by Dionic water tester.

🔳Chemical Characteristics of drinking water

🔻 Total Dissolved solids (<500)

👉 Total solids can be found by evaporating a sample of water and weighing the dry residue left.

👉 Suspended solids can be found by filtering water sample through Whatman filter paper No.44

🔻 pH (6.5 to 8.5)

👉 It is measure hydrogen ion concentration in water.

👉 It is measure by Potentiometer and Colorimetric method

▪️ Alkalinity - It is caused by bicarbonates of Ca & Mg and carbonates, hydroxides of Ca, Mg, Na, K.

▪️ Acidity - It is caused by Mineral Acids, Free Co2, Sulphates of Fe & Aluminium.

▪️ Alkalinity effect - Incrustation and sediment deposit in pipelines and difficult in chlorination.

▪️ Acidity effects - Tuberculation & Corrosion of pipe lines.

👉 Alkalinity and Acidity is estimated by Titrometry.

👉 Total Alkalinity < 200 mg/l as CaCo3

🔻 Hardness (<200 ppm)

👉 It is measured by EDTA test( Versante method)

👉 Temporary hardness caused by Bicarbonates and carbonates of Ca & Mg

👉 Permanent hardness caused by sulphate, chloride and nitrate of ca & Mg.

💢 1 French degree hardness = 10 ppm

💢 1 British degree hardness = 14.25 ppm

💢 1 American degree hardness = 17.15 ppm

🔳Chemical Characteristics of drinking water

🔻 Chloride content(≤ 250mg/l)

💡 It causes kidney and cardiac problem

💡 Chlorides in water estimated by Mohr's method.

🔻 Sulphates (<250mg/l)

💡 It causes diarrhea.

🔻 Dissolved oxygen ( 3-4 ppm)

💡 High DO causes Corrosion.

💡 DO in water estimated by Winkler's Method

💡 DO inversely proportional to temperature.

🔻 BOD :- Nil

🔻 Fluoride (1ppm - 1.5 ppm)

💡 Fluoride in water estimated by Colourometry using Zirconium.

💡 Fluoride < 1ppm cause formation of cavities in teeth.

💡 Fluoride > 1.5ppm causes Fluorosis (molting of teeth) and deformation of bones.

🔻 Nitrogen Content

💡 drinking water standard

Ammonia Nitrogen - < 0.15 mg/l

Organic Nitrogen - < 0.3 mg/l

Nitrites - Nil

Nitrates - <45 mg/l

💡 Total Kjeldahl Nitrogen (TKN) :- Free ammonia + Organic Nitrogen.

💡 Excess causes the disease called Methemoglobinemia (Blue baby disease).

🔻 Iron & Manganese (Fe < o.3 mg/l & Mn <0.05 mg/l)

💡 Iron causes reddish colour to water

💡 Manganese causes brown colour

💡 It is estimated by Colormetry

🔻 Copper (1 - 2 mg/l)

💡 It affects human lungs and other respiratory organs.

What is Development Length
https://www.gyanimohan.xyz/2020/09/what-is-development-length.html