K2Cr2O7 Content (%)

initial concentration – paste (g·L−1)

final concentration - extract (g·L−1)

efficiency (%)

7 days

28 days

7 days

28 days

0.50

4.42

1.98E−03

2.31E−03

99.96

99.95

1.00

8.84

3.59E−03

5.74E−03

99.96

99.94

1.50

13.26

8.02E−03

9.03E−03

99.94

99.93

2.00

17.67

1.34E−02

1.44E−02

99.92

99.92

2.50

22.09

2.18E−02

2.03E−02

99.90

99.91