Fig. 3. Removal of COD and BOD in different strengths of wastewater in tomato
aquaponics at the termination of the experiment. Unlike superscripts (a–d or A–E)
denote significant difference between treatment means at 5% level (
P < 0.05) among
different strengths of wastewater and vice versa.
and 100% wastewater was significant (one way ANOVA,
P < 0.05;
Tukey’s test,
P < 0.05; Fig. 3).
3.6. BOD removal efficiency
BOD as a dependent variable of COD also declined in all strengths
of wastewater. Its average removal ranged from 61.61% (25%
wastewater) to 72.03% (100% wastewater) irrespective of control (−4%) (Fig. 3). The removal efficiency increased significantly (one
way ANOVA,
P < 0.05; Tukey’s test,
P < 0.05) with increasing the
strength of wastewater, except between 25% and 50% wastewater