Table 1 Impregnated materials and activated carbons derived from Pterocarpus indicus twigs.

From: Twigs-derived activated carbons via H3PO4/ZnCl2 composite activation for methylene blue and congo red dyes removal

Mass ratio

Sample coding

Twigs raw material (TRM)

ZnCl2

H3PO4

Impregnated material

Activated carbon

1

0

0

imTRM1

TAC1

1

1

0

imTRM2

TAC2

1

0

1

imTRM3

TAC3

1

0.5

0.5

imTRM4

TAC4

1

0.25

0.75

imTRM5

TAC5

1

0.75

0.25

imTRM6

TAC6