Supporting Information s3

Supporting Information

Sorption Kinetics In order to investigate the adsorption process of KOH-AC for iodine uptake, the frequently used pseudo first order and pseudo second order models were used. The corresponding equations were given in Equation (1)-(2). Pseudo first order kinetic model:

ln(qe- q t ) = ln qe - k 1 t (1) Pseudo-second-order model: t1 t = + q k q2 q (2) t 2 e e

-1 Where qe and qt are the amount of iodine adsorbed at time t and equilibrium (mg g ), -1 k1 is the pseudo-first-order rate constant of adsorption process (h ). k2 is the pseudo- first-order rate constant of adsorption process (g mg-1 h-1).

6 0.5 (a) (b) 4 0.4

2 1 - 0.3 ) t g q - m e

0.2 ( n

-2 / -1 2 t 300 mg L R =0.8489 0.1 300 mg L-1 R2=0.9961 -4 500 mg L-1 R2=0.7538 500 mg L-1 R2=0.9962 0.0 0 20 40 60 80 100 0 20 40 60 80 100 t ( h ) t ( h ) Fig. S1 The pseudo-first-order (a) and the pseudo-second-order absorption kinetics model (b) KOH-AC for iodine uptake in cyclohexane solution.

Adsorption isotherm models To describe the experimental data of adsorption isotherms, Langmuir and Freundlich models were employed. The corresponding equations were given in Equation (3)-(6). Langmuir isotherm model:

Qm k L c e qe = (3) 1+ kL c e

c c 1 e= e + (4) qe Q m k L Q m Freundlich isotherm model: 1 qe= k c n (5) F e

1 ln c lnq=e + ln k (6) en F -1 Where ce is the concentration at equilibrium (mg L ), qe is the amount of adsorbed -1 -1 -1 iodine at equilibrium (mg g ). kL (mg ) and Qm (mg g ) are the Langmuir isotherm -1 constants; kF (mg ) and n are the Feundlich isotherm constants.

12 (a) 6.2 (b) 10 6.1 6.0 8 )

1 5.9 - L 5.8 g 6 e (

n 5.7 e l Q / 4 Freundlich e Langumir 5.6

C 2 2 5.5 R =0.7845 2 R =0.9968 5.4 0 5.3 0 1000 2000 3000 4000 5000 5.5 6.0 6.5 7.0 7.5 8.0 8.5 Ce (mg L-1) ln Ce Fig. S2 Adsorption isotherm of iodine onto KOH-AC. (a) Langmuir isotherm model, (b) Freundlich isotherm model.