Taguchi-Based Process Optimization for Improving Iron Removal …
329
2.2 Experimental Matrix Designing by Taguchi Method
Influential parameters affecting EC process were studied from various literatures.
Parameters like the initial concentration of iron, current intensity, inter-electrode
distance, conductivity, and initial pH were chosen. Taguchi method was implemented
to analyze the effects of these parameters and to obtain the regression equation (Tir
et al. 2015; Irdemezet al. 2006). In this work, orthogonal array OA 16 (4
5 ) with five
different parameters (P) of four different levels (L) were implemented. The level of
each of the chosen parameters is shown in Table 1. N is the number of runs required
for the orthogonal array, which is recognized using Eq. (1):
N = (L − 1)P + 1
( 1 )
There are 16 experiments (L 16 ) to be carried out as per the Taguchi methodology
and are shown in Table 2 (Karmakar et al. 2018). Minitab-17 software was utilized to
implement Taguchi method for obtaining the optimized parameter values, the effectiveness of the parameters, and the regression equation. Each experiment was repeated
at least three times to obtain the experimental removal efficiency (Martinez-villafane
and Montero-Ocampo 2010). To evaluate the effect of parameters and to obtain
their optimized value a response is chosen. In this study, the percentage removal of
iron is chosen as the response of the Taguchi method, and experimental data were
analyzed using the signal-to-noise (S/N) ratio. Since better the removal of iron from
the solution, the “larger is better” characteristic has been chosen.
S
N
= −10log 10
1
n
n
i=1
1
y
2
i
(2)
where S/N is the sound to noise ratio, n is the number of repetitions for one
experimental combination, and y i is the performance value of the ith experiment
(Asghari et al. 2012).
Table 1 Experimental parameters and levels for the removal of iron using electrocoagulation
Variables
Levels
1
2
3
4
Initial concentration (ppm)
15
20
25
30
Current intensity (A)
0.5
0.75
1
1.25
Inter-electrode distance (mm)
8
10
12
14
Conductivity (µS)
345
355
365
375
Initial pH
5
6
7
8
329
2.2 Experimental Matrix Designing by Taguchi Method
Influential parameters affecting EC process were studied from various literatures.
Parameters like the initial concentration of iron, current intensity, inter-electrode
distance, conductivity, and initial pH were chosen. Taguchi method was implemented
to analyze the effects of these parameters and to obtain the regression equation (Tir
et al. 2015; Irdemezet al. 2006). In this work, orthogonal array OA 16 (4
5 ) with five
different parameters (P) of four different levels (L) were implemented. The level of
each of the chosen parameters is shown in Table 1. N is the number of runs required
for the orthogonal array, which is recognized using Eq. (1):
N = (L − 1)P + 1
( 1 )
There are 16 experiments (L 16 ) to be carried out as per the Taguchi methodology
and are shown in Table 2 (Karmakar et al. 2018). Minitab-17 software was utilized to
implement Taguchi method for obtaining the optimized parameter values, the effectiveness of the parameters, and the regression equation. Each experiment was repeated
at least three times to obtain the experimental removal efficiency (Martinez-villafane
and Montero-Ocampo 2010). To evaluate the effect of parameters and to obtain
their optimized value a response is chosen. In this study, the percentage removal of
iron is chosen as the response of the Taguchi method, and experimental data were
analyzed using the signal-to-noise (S/N) ratio. Since better the removal of iron from
the solution, the “larger is better” characteristic has been chosen.
S
N
= −10log 10
1
n
n
i=1
1
y
2
i
(2)
where S/N is the sound to noise ratio, n is the number of repetitions for one
experimental combination, and y i is the performance value of the ith experiment
(Asghari et al. 2012).
Table 1 Experimental parameters and levels for the removal of iron using electrocoagulation
Variables
Levels
1
2
3
4
Initial concentration (ppm)
15
20
25
30
Current intensity (A)
0.5
0.75
1
1.25
Inter-electrode distance (mm)
8
10
12
14
Conductivity (µS)
345
355
365
375
Initial pH
5
6
7
8