Research Article

Optimization and Modeling of Cr (VI) Removal from Tannery Wastewater onto Activated Carbon Prepared from Coffee Husk and Sulfuric Acid (H2SO4) as Activating Agent by Using Central Composite Design (CCD)

Figure 7

3D image for Cr (VI) adsorption, (a) dose (g/L) vs. pH, (b) contact time (hr.) vs. pH, (c) contact time (hr.) vs. dose (g/L).
(a)
(b)
(c)