Temkin Isotherm Model

The values of qe versus ln Ce were plotted so that linearised form of Temkin model is obtained in the form of qe = A ? B ln Ce, whereby A is the y intercept and B is the gradient. The linearised Temkin model are illustrated in Figs. 30, 31, 32, 33, 34 and 35 followed by a summary Table 9 that gives the calculated values of the Temkin parameters. The R2 values obtained from the linear method were above

Fig. 30 The linearized Temkin model of RR158 by CAC's. Experimental conditions: room temperature; agitation rate: 200 rpm; biomass dosage: 7.5 g/L; pH: 2
Fig. 31 The linearized Temkin model of RR158 by CAC's. Experimental conditions: room temperature; agitation rate: 200 rpm; biomass dosage: 10 g/L; pH: 2

0.980 which indicated that the Temkin model was well fitted to the experimental data. The parameters of bT increased with increasing initial dye concentration from 20 mg/L to 120 mg/L. The values of bT were in the range of -917.96 to -168.43 at fixed adsorbent dosage of 7.5 g/L, -1394.24 to -222.01 for adsorbent dosage

Fig. 32 The linearized Temkin model of RR158 by CAC's. Experimental conditions: room temperature; agitation rate: 200 rpm; biomass dosage: 12.5 g/L; pH: 2
Fig. 33 The linearized Temkin model of RR158 by CAC's. Experimental conditions: room temperature; agitation rate: 200 rpm; biomass dosage: 15 g/L; pH: 2

of 10 g/L, -1637.52 to -280.62, -1949.31 to -348.71, -3093.01 to -398.71 and -1266.01 to -164.62 for adsorbent dosages of 12.5, 15, 17.5 and 20 g/L respectively. It was also observed that the bT values lied in a wider range as the

Fig. 34 The linearized Temkin model of RR158 by CAC's. Experimental conditions: room temperature; agitation rate: 200 rpm; biomass dosage: 17.5 g/L; pH: 2
Temkin Model
Fig. 35 The linearized Temkin model of RR158 by CAC's. Experimental conditions: room temperature; agitation rate: 200 rpm; biomass dosage: 20 g/L; pH: 2
Table 9 Summary of results of Temkin constant

Initial dye concentration (mg/L)

R2

bT

At

R2

bT

At

Adsorbent

dosage: 7.5 g/L

Adsorbent

dosage: 15 g/L

20

0.998

-917.959

0.045

0.997

-1949.309

0.045

40

0.999

-480.243

0.024

0.996

-1124.125

0.024

60

0.999

-352.629

0.017

0.998

-748.737

0.016

80

0.999

-256.106

0.013

0.999

-501.939

0.012

100

1.000

-194.931

0.010

0.998

-427.462

0.010

120

0.999

-168.428

0.008

0.998

-348.708

0.008

Adsorbent

dosage: 10 g/L

Adsorbent

dosage: 17.5 g/L

20

0.999

-1394.244

0.050

0.980

-3093.099

0.042

40

0.999

-662.630

0.025

0.996

-1432.123

0.024

60

0.999

-436.346

0.016

0.999

-840.425

0.016

80

0.999

-329.027

0.012

0.999

-594.142

0.012

100

0.999

-283.897

0.010

0.983

-517.779

0.010

120

0.999

-222.005

0.008

0.998

-398.708

0.008

Adsorbent

dosage: 12.5

g/L

Adsorbent

dosage: 20 g/L

20

0.997

-1637.523

0.045

0.980

-1266.005

0.040

40

-

-

-

0.992

-625.334

0.024

60

0.998

-624.703

0.016

0.992

-406.093

0.016

80

0.999

-396.920

0.012

0.997

-275.194

0.012

100

0.997

-344.682

0.010

0.998

-223.810

0.010

120

0.999

-280.618

0.008

0.999

-164.623

0.008

adsorbent dosage increases such that for adsorbent dosage of 7.5 g/L, the range was 749, and 1172, 1357, 1601 and 2695 for adsorbent dosage of 10.0, 12.5, 15.0, 17.5 and 20 g/L respectively. The AT values were constant at constant initial dye concentrations with varying adsorbent dosages. The dye solution of initial concentration of 80 mg/L at varying dosages of adsorbent from 7.5 to 20 g/L gives an At value equal to 0.12. AT values were 0.050 for dye concentration of 20 mg/L, 0.024 for dye concentration of 40 mg/L, 0.016-0.017 for dye solution of 60 mg/L, 0.010 for dye solutions of 100 mg/L and 0.008 for dye concentration of 120 mg/L at varying adsorbent dosages of 7.5 to 20 g/L. AT values increased as the dyes concentration ascended.

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