Taguchi-Based Process Optimization for Improving Iron Removal …
331
plates were used as electrodes with dimensions of 100 mm × 30 mm × 1.5 mm. A
perplex rod was used to support the anode and cathode. The inter-electrode distance
varied from 8 to 14 mm. A DC power supply (Make: Aplab L6410 S) was connected
to maintain a steady flow of current. A constant speed was maintained in the EC
setup using a magnetic stirrer (Make: Remi 5 MLH Plus). The experiments were
conducted at ambient temperature (25 ± 1 °C). The pH was varied for the experiments using 0.1 M solution of H 2 SO 4 and NaOH. NaCl was used as the electrolyte.
Each experiment had a fixed time span of 40 min. Samples were withdrawn at the
end of the experiment and filtered through filter paper (Whatman Cat No 1001-110)
and electrodes were cleaned by dilute HCl after each experiment.
The filtered sample was analyzed using ICP–OES spectrometry (Make:
Perkin Elmer Optima 8000). The percentage removal of iron was calculated using
the following equation:
Removal efficiency =
C i − C f
C i
× 100
(3)
where C i and C f are the initial and final concentrations of iron solutions in mg L
−1 ,
respectively (Hashim et al. 2019). Conductivity and pH were measured by multimeter
meter (Make: EUTECH Instruments PC2700).
2.4 Analysis of Variance
Electrocoagulation of iron solution was performed in accordance with the set of
parametric conditions acquired by experimental matrix design using L 16 orthogonal
array methodology. The removal efficiency of iron using monopolar electrocoagulation process was analyzed statistically for an assessment of the importance of the
model selected for optimization and the effects of separate process parameters on
the response by means of ANOVA studies. ANOVA is a dynamic technique used to
inspect the importance of a discrete parameter and selected the optimization model
for the establishment of a mathematical model equation. It emphasizes on the analysis
of the variance around the mean of the performance features and is accomplished
by assessing the Fischer’s test value (F-value). The influence of any parameter is
elucidated by its F-value and the corresponding sum of squares (Shah et al. 2017).
Higher F-value and sum of squares of any parameter specify its comparative importance in the procedure of the response. Contrariwise, the extents of acquired values
of these tests are entirely owed to response signals and are assured by a p-value. The
p-value simplifies the probability of attaining an F-value of this order due to noise
values below 0.05 or 5% confirms the significance of the specific process parameter
(Pundir et al. 2018).
331
plates were used as electrodes with dimensions of 100 mm × 30 mm × 1.5 mm. A
perplex rod was used to support the anode and cathode. The inter-electrode distance
varied from 8 to 14 mm. A DC power supply (Make: Aplab L6410 S) was connected
to maintain a steady flow of current. A constant speed was maintained in the EC
setup using a magnetic stirrer (Make: Remi 5 MLH Plus). The experiments were
conducted at ambient temperature (25 ± 1 °C). The pH was varied for the experiments using 0.1 M solution of H 2 SO 4 and NaOH. NaCl was used as the electrolyte.
Each experiment had a fixed time span of 40 min. Samples were withdrawn at the
end of the experiment and filtered through filter paper (Whatman Cat No 1001-110)
and electrodes were cleaned by dilute HCl after each experiment.
The filtered sample was analyzed using ICP–OES spectrometry (Make:
Perkin Elmer Optima 8000). The percentage removal of iron was calculated using
the following equation:
Removal efficiency =
C i − C f
C i
× 100
(3)
where C i and C f are the initial and final concentrations of iron solutions in mg L
−1 ,
respectively (Hashim et al. 2019). Conductivity and pH were measured by multimeter
meter (Make: EUTECH Instruments PC2700).
2.4 Analysis of Variance
Electrocoagulation of iron solution was performed in accordance with the set of
parametric conditions acquired by experimental matrix design using L 16 orthogonal
array methodology. The removal efficiency of iron using monopolar electrocoagulation process was analyzed statistically for an assessment of the importance of the
model selected for optimization and the effects of separate process parameters on
the response by means of ANOVA studies. ANOVA is a dynamic technique used to
inspect the importance of a discrete parameter and selected the optimization model
for the establishment of a mathematical model equation. It emphasizes on the analysis
of the variance around the mean of the performance features and is accomplished
by assessing the Fischer’s test value (F-value). The influence of any parameter is
elucidated by its F-value and the corresponding sum of squares (Shah et al. 2017).
Higher F-value and sum of squares of any parameter specify its comparative importance in the procedure of the response. Contrariwise, the extents of acquired values
of these tests are entirely owed to response signals and are assured by a p-value. The
p-value simplifies the probability of attaining an F-value of this order due to noise
values below 0.05 or 5% confirms the significance of the specific process parameter
(Pundir et al. 2018).