(a) Aeration chamber
(b) Clarifier
(c) Chlorination chamber
(d) SO2 chamber
Figure 5: ((a)–(d)) UV-Vis spectra of samples spiked with 5, 10, and 15 mL of 0.5 ppm Cr(VI) standard solution from the four treatment stages: aeration, clarifier, chlorination chamber, and sulfur dioxide chamber.