Determination of Hexavalent Chromium (Cr(VI)) Concentrations via Ion Chromatography and UV-Vis Spectrophotometry in Samples Collected from Nacogdoches Wastewater Treatment Plant, East Texas (USA)

Table 3

Comparison of Cr(VI) concentrations to other literature studies in river, wastewater, and drinking waters.

Samples	[Cr(VI)] amounts	Reference
River samples	3.7–3.31 ppb	[7]
	4.2 ppb	[8]
	Below detection limits	[9]
	0.03–2 ppb	[10]
	0.097–9.84	[11]
	31–498 ppm (in lakes)	[12]
	21–984 ppm (in tap water)	[12]
Wastewater samples	25.1–45.5 ppb	[13]
	1.2–6.7 ppm	[14]
	567.2 ppb	[15]
	4–9 ppb	This study
Drinking water samples	0.12–20 nM	[16]
	14 nM	[16]
	0.3–1.0 ppb	[17]