Adding either NaOH or Na2CO3 ...

Published by

Adding either NaOH or Na2CO3 (very small quantities are necessary) will let you achieve your target.

However the full appreciation of the result requires for the following general considerations:

a) pH of drinking water is not a must and 7.1 can be very well acceprable (why to raise it?)

b) Na is considered a salt to be kept at minimum concentration in high quality dinking water (it is suspected to be harmful for heart because raising the blood pressure).

Hence I recommend prudence in correction of pH.

I attach the analysis of some of the best quality Italian bottled mineral water, and you can use it as a guideline for your added pH correctors

Italian Natural Bottled Water Analysis

 

Samples

1

2

3

4

5

6

7

 

 

Vera Nestlè

Levissima

Laurentana

Rocchetta

Conad

xxx 

Ferrarelle

Conductivity

µS/cm

251

119

15,2

276

250

216

181

pH

 

7,9

7,8

6,3

7,6

7,8

8,0

6,1

Ca++

ppm

35,9

20,4

1,5

57,4

40,2

32,0

48,0

Mg++

ppm

12,6

1,8

0,4

3,2

4,2

6,2

2,4

Na+

ppm

2,8

1,9

1,0

4,1

14,0

6,4

5,0

K+

ppm

0,5

1,6

0,2

0,3

0,2

0,8

4,6

HCO3-

ppm

148,0

57,4

5,0

182,1

139,0

103,0

148,0

SO4--

ppm

19,3

16,1

1,2

6,8

29,8

22,0

5,0

Cl-

ppm

2,4

NA

0,4

6,8

NA

8,5

1,8

NO3-

ppm

4,4

1,5

2,3

1,1

1,0

2,9

5,0

F-

ppm

NA

0,2

NA

0,1

NA

0,1

1,1

SiO2

ppm

NA

5,4

4,5

4,2

NA

7,0

8,5

Total TDS

ppm

225,9

106,3

16,5

266,1

228,4

188,9

229,4

Dry solids (180°C)

ppm

163

80

14

174

173

139,0

NA

 

 

1 Comment

Thanks for the input.

a) In first case, we raise pH a bit using Na2CO3 to enhance iron precipitation.

b) For the second case, we are using NaOH because it adds only a little amount of Na+ ions copared to Na2CO3.

We are planning to include a pH monitoring unit as a fail safe.

Published by

Permalink