Table 5.

Effect of pH on biosorption efficiency (%) of the heavy metals Ni²⁺, Cr⁶⁺ and Zn²⁺ by live and dead biomass of Nocardiopsis sp. MORSY1948 and Nocardia sp. MORSY2014.

Biosorbent	Heavy metal	Biosorption efficiency (%) at different pH values
		2	4	6	7	8	9	10	11
Nocardiopsis sp. MORSY1948 (live cells)	Ni2+	19.23	27.08	39.4	42.54	39.59	17.50	11.65	7.15
Cr6+	8.14	20.51	28.0	35.72	31.00	26.23	11.47	9.07
Zn2+	12.06	18.93	37.9	41.40	46.91	34.72	20.51	12.32
Nocardiopsis sp. MORSY1948 (dead cells)	Ni2+	25.39	42.17	60.5	87.90	87.90	70.04	53.58	50.05
Cr6+	18.50	20.36	47.5	63.75	63.75	52.57	38.35	19.49
Zn2+	14.92	29.08	67.8	75.15	84.15	68.31	40.01	32.28
Nocardia sp. MORSY2014 (live cells)	Ni2+	5.08	18.40	49.32	59.65	61.46	42.70	38.24	22.70
Cr6+	11.54	22.00	38.47	60.85	62.52	60.38	31.90	12.04
Zn2+	18.72	35.09	50.32	64.30	67.91	54.02	40.85	26.16
Nocardia sp. MORSY2014 (dead cells)	Ni2+	14.85	47.95	80.30	88.71	93.53	80.81	51.93	30.78
Cr6+	20.04	34.78	75.52	84.57	95.22	77.10	70.07	42.05
Zn2+	25.37	50.03	76.87	87.95	90.37	85.20	61.44	50.00