Samples

pH before filtration (average value)

pH after filtration (average value)

1

7.27

7.07

2

6.97

7.08

3

6.95

6.96

4

6.65

7.1

5

6.51

6.98

6

6.73

7.08

7

6.55

7.07

8

6.61

6.87

9

6.54

7

10

6.5

6.98

Average

6.728

7.019

Deviation

0.2556

0.0732