Table 2. Pseudo-second order rate constants for the sorption of Pb²⁺ and Cu²⁺ by unmodified (UM) and mercaptoacetic acid modified (M) biomass of Nipah palm.

Metal ion

q_e, mg/g

k₂, g/mg min

h, mg/g min

R²

Pb²⁺

UM

15.59

3.59 x 10^-3

0.89

0.9996

M

21.85

1.85 x 10^-4

0.09

0.9996

Cu²⁺

UM

52.86

2.92 x 10^-2

81.59

1.000

M

66.71

3.67 x 10^-2

159.86

0.9996