Experimental factors

Coded levels

Time
(min)

Temperature
(ºC)

Neutral microstructured materials (g/L)

Erythromycin (mM)

-

6.5

25

0.3

0.8

-1

20.0

35

2.0

1.5

0

40.0

50

4.5

2.5

1

60.0

65

7.0

3.5

73.5

75

8.7

4.2

Sorbent

k1 (min-1)

qmax (mmol/g)

30 ºC

40 ºC

50 ºC

60 ºC

30 ºC

40 ºC

50 ºC

60 ºC

XAD-16N™

0.015

0.025

0.030

0.020

0.24

0.25

0.40

0.40

XAD-18™

0.025

0.035

0.032

0.029

0.25

0.35

0.47

1.34

XAD-1600N™

0.015

0.022

0.030

0.030

0.32

0.32

0.50

0.45

Sorbent

Freundlich Model

        Langmuir Model

kf

n

qmax  (mmol/g)

kL
(mmol/L)

RL

XAD-16NTM

0.14

0.17

0.15

0.05

0.04

XAD-18TM

0.19

0.80

0.64

2.32

0.77

XAD-1600NTM

0.20

0.57

0.35

0.70

0.46

Sorbent

ΔHads (kJ/mol)

ΔGads (kJ/mol)

ΔSads (J/mol.K)

XAD-16NTM

 3.68

 52.47

16.10

XAD-18TM

 2.56

 1.10

 4.80

XAD-1600NTM

 2.72

 3.60

   2.90

Variables

Residual [Erythromycin] (mM)

XAD-16N

XAD-18

XAD-1600N

(p)

(p)

(p)

Time (Linear term)

-0.4002

(0.0408*)

-0.3625

(0.1627)

-0.7010

(0.0126)

Time (Quadratic term)

0.6777

(0.0045**)

0.5051

(0.0343*)

0.4904

(0.0123*)

Temperature (Linear term)

-0.4208

(0.0333*)

-0.4592

(0.1018)

-0.3867

(0.0594)

Temperature (Quadratic term)

0.5628

(0.0124*)

0.3902

(0.0646)

0.2461

(0.0726)

[Sorbent] (Linear term)

-0.6053

(0.0057**)

-0.6321

(0.0155*)

-0.8264

(0.0022**)

[Sorbent] (Quadratic term)

0.5053

(0.0208*)

0.1458

(0.3636)

0.3035

(0.0439*)

[Erythromycin] (Linear term)

1.6046

(0.0000***)

1.1360

(0.0103**)

1.0635

(0.0039*)

[Erythromycin] (Quadratic term)

0.4334

(0.0400*)

0.1027

(0.5063)

-0.0126

(0.8978)

Time x Temperature

-0.3461

(0.5564)

-1.1099

(0.0229*)

-0.7556

(0.0214*)

Time x [Sorbent]

0.0610

(0.8681)

0.1524

(0.4249)

-0.0915

(0.4657)

Time x [Erythromycin]

-0.2307

(0.6897)

-0.2865

(0.3464)

-0.3969

(0.1024)

Temperature x [Sorbent]

-0.0813

(0.8252)

0.3963

(0.0963)

0.3354

(0.0552)

Temperature x [Erythromycin]

0.0643

(0.9102)

0.0541

(0.8468)

-0.2436

(0.2484)

[Sorbent] x [Erythromycin]

-0.0813

(0.8252)

-0.1118

(0.5477)

-0.2947

(0.0747)

Sorbent

Model Equations

R2

R2adj

XAD-16NTM

[Erythromycin]Residual = 7.0106 – 0.0778Time – 0.00085 Time2 – 0.1391Temperature + 0.0013Temperature2 – 0.4849[XAD-16N] + 0.0404[XAD-16N]2 – 0.28124 [Erythromycin] + 0.2167[Erythromycin]2

0.939

0.885

XAD-18TM

[Erythromycin]Residual =  0.00063Time2 – 0.00185 Time x Temperature + 0.00447Temperature x [XAD-18]

0.989

0.941

XAD-1600NTM

[Erythromycin]Residual = 0.0006Time2 – 0.4235[XAD-1600N] + 0.0243 [XAD-1600N]2 – 1.6316[Erythromycin] - 0.0013Time x Temperature + 0.00447Temperature x [XAD-1600N]

  0.995

  0.969