Removal of Cr(VI) from Aqueous Solutions Using Powder of Potato Peelings as a Low Cost Sorbent

Table 2

(a) Kinetic parameters for the adsorption of Cr(VI) onto potato peel powder at 𝑇=27°C. (b) Averaged kinetic parameters for the adsorption of Cr(VI) onto potato peel powder at 𝑇=27°C.

(a)

Kinetic model	Linear equation	Initial Cr(VI) concentration, mg/L	Reaction constant	𝑅^2
Pseudo-first-order	log(𝑞𝑒−𝑞𝑡)=log𝑞𝑒−𝑘1𝑡2.303	40	𝑘1=0.0230 min^−1	0.842
		60	𝑘1=0.0115 min^−1	0.882
		100	𝑘1=0.0115 min^−1	0.906
		120	𝑘1=0.0046 min^−1	0.870
Elovich	𝑞𝑡=1𝛽+1ln𝛼𝛽𝛽ln𝑡	20	𝛼=0.0081 mg·g^−1·min^−1; 𝛽=11.11 g/mg	0.907
		40	𝛼=0.0227 mg·g^−1·min^−1; 𝛽=2.3923 g/mg	0.965
		60	𝛼=0.0518 mg·g^−1·min^−1; 𝛽=2.6316 g/mg	0.861
		100	𝛼=0.5897 mg·g^−1·min^−1; 𝛽=2.4390 g/mg	0.902
		120	𝛼=0.3663 mg·g^−1·min^−1; 𝛽=1.8315 g/mg	0.956

(b)

Kinetic model	Linear equation	Reaction constant
Pseudo-first-order	log(𝑞𝑒−𝑞𝑡)=log𝑞𝑒−𝑘1𝑡2.303	𝑘1=0.01267±0.00764 min^−1
Elovich	𝑞𝑡=1𝛽+1ln𝛼𝛽𝛽ln𝑡	𝛼=0.25763±0.3440 mg·g^−1·min^−1; 𝛽=2.3236±0.27054 g/mg