Fig. 9

Pareto chart of standardized effect on Cr⁶⁺ removal by TAM using Plackett–Burman design (response is percentage removal, α = 0.05). (A: Contact time (min.); B: Cr concentration (mg L⁻¹); C: pH; D: Temperature (°C); E: Biomass dosage (g); F: Static-Agitation).