Water hardness pH PO 4 3- NO 2 -, NO 3 - NH 4 + Fe.

•water hardness•pH•PO4

3-

•NO2-, NO3

-

•NH4+

•Fe

WATER HARDNESSWater hardness is caused by divalent ions, especially Ca2+ and

Mg2+.The measure for water hardness is 1°d (=10mg CaO/L water).Classification:

0 – 4 °d…. very soft water 4 – 8 °d…. soft water8 – 12 °d …. medium soft water12 – 18 °d …. pretty hard water18 – 30 °d …. hard waterover 30 °d …. very hard water

Our resultsSAMPLE Water hardness

School tap water 11

Rahtel tap water 3

Vuhred tap water 7

Šoštanj tap water 10

Spring Velenje 9

Spring Šoštanj 6

Velenje lake 18

River Homšnica 4

pHpH is criteria of acidness and baseness of water.pH = -log [H30+][H30+] > 10-7 => pH < 7 (acid)[H30+] = 10-7 => pH = 7 (neutral)[H30+] < 10-7 => pH > 7 (base)

Our resultsSAMPLE pH

School tap water 8

Rahtel tap water 6,5

Vuhred tap water 7

Šoštanj tap water 8

Spring Velenje 7,5

Spring Šoštanj 7,5

Velenje lake 8

River Homšnica 7,5

• natural water has pH between 6 and 8• drinking water => pH = 6,5 – 8,5 (EC rules)

PO43-

Natural unpolluted water contains less than 0,1 mg/L of all the PO4 (higher concentrations are caused by human pollution).

Sources of pollution:phosphoric manures washing and detergentsphosphating (transformation of metal surfaces into

phosphates as a protection from rusting)

Our resultsSAMPLE PO4

3-

School tap water 0,3

Rahtel tap water 0,5

Vuhred tap water 0

Šoštanj tap water 0,5

Spring Velenje 0,5

Spring Šoštanj 0,5

Velenje lake 0,1

River Homšnica 0,5

• drinking water => PO43- = 0,6 mg/L (EC rules)

NO2-, NO3

-

Nitrates (NO3-) are the major polluters of ground water

and also of many fluent and influent waters.Sources of pollution:

artificial manuresintensive stockbreedingpoor infrastructure (sewage)

The functioning key of nitrates is transformation into nitrites (NO2

-).

Our resultsSAMPLE NO3

- NO2-

School tap water 10 0,2

Rahtel tap water 0 0,2

Vuhred tap water 10 0,2

Šoštanj tap water 10 0,2

Spring Velenje 10 0,2

Spring Šoštanj 10 0,2

Velenje lake 10 0,2

River Homšnica 10 0,1

• drinking water => NO3- = 25 mg/L (EC rules)

• drinking water => NO2- = max. 0,1 mg/L (EC rules)

NH4+

The presence of ammonium in water shows that the water was in contact with rotting organic materials, fecals..

Our resultsSAMPLE NH4

+

School tap water 0,05

Rahtel tap water 0,2

Vuhred tap water 0,2

Šoštanj tap water 0,2

Spring Velenje 0,05

Spring Šoštanj 0,05

Velenje lake 0,2

River Homšnica 0,2

• drinking water => NH4+ = 0,05 mg/L (EC rules)

FeIron is often presented in water.It represents over 5% of Earth bark and by water

absorbing it, iron comes in the water.It causes a lot of troubles

rusted stains on clothes (washed in washing machine)iron coating on pipes

Our resultsSAMPLE Fe

School tap water 0,3

Rahtel tap water 0,6

Vuhred tap water 0,2

Šoštanj tap water 0,4

Spring Velenje 0,1

Spring Šoštanj 0,1

Velenje lake 0,3

River Homšnica 0,4

• drinking water => Fe = max. 2 mg/L

WATER IN SLOVENIATo conclude:

all pH values of drinking water are according to EC rulesall PO4

3- values meet EC rules NO2

- and NO3-

ground water that contains over 25 mg NO3- /L

water of Drava field water of Ptuj field water of Spodnja Savinjska valley water of Prekmurje field

Only both sources and school tap pipe water are according to NH4

+ valueall Fe values meet EC rules