Optimization of Precious Metals Recovery from Electronic Waste by Chromobacterium violaceum Using Response Surface Methodology (RSM)

Table 1

Levels and factors variables in the experimental design.

Factors	Variables	Units	Code levels
			−1	0	+1
X1	Oxygen level	(mgL^−1)	0.0	0.5	1.0
X2	E-waste pulp density	(%)	0.50	2.75	5.00
X3	Glycine concentration	(mgL^−1)	0.750	2.625	4.500