Figure 5

Three-dimensional surface plot of Cu2+ removal % by Azotobacter nigricans NEWG-1, showing the interactive effects of two variables at a time of the three tested variables factors, holding the third factor at the center point.
Three-dimensional surface plot of Cu2+ removal % by Azotobacter nigricans NEWG-1, showing the interactive effects of two variables at a time of the three tested variables factors, holding the third factor at the center point.