Table 3.

Chemical composition (EDS) of pure CuO and electroplating sludge.

Sample	Element (wt%)
	C	O	Cu	Mg	P	S	Ca	Cr	Ni	Total
CuO	8.54	13.89	77.57	-	-	-	-	-	-	100
Sludge	16.09	37.99	3.7	0.88	5.47	2.2	11.51	11.57	10.59	100