Determination of Kinetic and Equilibrium Parameters of Chromium Adsorption from Water with Carbon Nanotube Using Genetic Programming

Figures & data

Table 1. Parameters used in GP.

Population size	Tournament size	Tree depth	Max gene depth	Fitness function
150	8	4	4	Regressmulti

Table 2. Comparison between precision of pseudo-first-order and pseudo-second-order equation at pH 2 and adsorbent dosage 0.01 g.

Temperature	Initial concentration mg/L	for pseudo-first order	for pseudo-second order
17	20	0.7923	0.9924
	40	0.8025	0.9941
27	20	0.8387	0.9955
	40	0.8436	0.9964
37	20	0.8736	0.9961
	40	0.8705	0.9969

Table 3. Constant rate of the pseudo-second-order kinetic at pH 2 and adsorbent dosage 0.01 g.

Initial concentration (mg/L)	Temperature
20	17	0.00499
	27	0.00607
	37	0.00705
40	17	0.001186
	27	0.001775
	37	0.001882

Figure 1. Arrhenius plot of versus 1/T for initial concentration 20 mg/L.

Figure 2. Arrhenius plot of versus 1/T for initial concentration 40 mg/L.

Table 4. Comparison of the square correlation coefficients between Langmuir and Freundlich isotherm models.

Temperature ()	for Langmuir isotherm	for Freundlich isotherm
17	0.93	0.81
27	0.96	0.76
37	0.97	0.83

Table 5. Constants of the Langmuir equation at the initial concentration of 20 mg/L.

Temperature ()
17	115.3	0.52
27	310.1	0.39
37	503.5	0.34

Figure 3. Arrhenius plot of versus 1/T.