Treatment of Wastewater by Ozone Produced in Dielectric Barrier Discharge

Table 2

Concentrations of lead, cadmium, and chromium before and after treatment by ozone.

Sample ID	Lead		Cadmium		Chromium
	Before ozonation	After ozonation	Before ozonation	After ozonation	Before ozonation	After ozonation
B1	0.07	ND (<0.01)	0.02	ND (<0.003)	0.03	0.04
B2	0.05	ND	0.01	ND	0.09	0.03
B3	0.02	ND	ND	ND	0.06	ND (<0.02)
B4	0.02	ND	ND	ND	0.06	ND
B5	0.02	ND	ND	ND	0.05	0.02
A1–A5	ND	ND	ND	ND	ND	ND

ND: not detected.