Removal efficiency of Pb, Cd, Cu and Zn from polluted water using dithiocarbamate ligands

Peer review under responsibility of Taibah University.

Figures & data

Scheme 1 The dithiocarbamate (a–c) and thioureide (d) tautomers.

Scheme 2 Structure of the dithiocarbamate ligands.

Scheme 3 The ligand-to-metal ratio in complex formation (M = Cu, Cd, Pb, Zn).

Fig. 1 Determination the of Cu ratio to (C₂H₅)₂NCS₂Na ligand.

Fig. 2 Determination of Cu ratio to (C₆H₅)₂ NCS₂Na ligand.

Table 2 Metal removal efficiency of diethyldithiocarbamate.

Metal	Initial concentration (ppm)	Remaining concentration in aqueous solution (ppm)	pH	Removal efficiency (%)
Cd	4.00	4.00	3.00	0.00
		0.531	5.30	86.72
		1.372	7.30	65.70
Pb	5.00	0.559	3.00	88.82
		2.703	5.30	45.94
		2.441	7.30	51.18
Zn	5.00	1.240	3.00	75.20
		2.493	5.30	50.14
		1.477	7.30	70.46
Cu	5.00	0.100	3.00	98.00
		0.229	5.30	95.42
		0.079	7.30	98.42

Table 3 Metal removal efficiency of dibenzyldithiocarbamate.

Metal	Initial concentration (ppm)	Remaining concentration in aqueous solution (ppm)	pH	Removal efficiency (%)
CD	4	0.591	3.00	85.22
		0.491	5.30	87.72
		0.481	7.30	87.97
		0.502	8.50	87.45
		0.508	11.00	87.30
Pb	5	0.554	3.00	88.90
		0.928	5.30	81.44
		0.652	7.30	86.96
		0.588	8.50	88.24
		0.330	11.00	93.40
Zn	5	0.572	3.00	88.56
		0.868	5.30	82.64
		0.231	7.30	95.38
		0.296	8.50	94.08
		0.212	11.00	95.76
Cu	5	0.098	3.00	98.04
		0.200	5.30	96.00
		0.070	7.30	98.60
		0.001	8.50	99.98
		0.345	11.00	93.10

Table 4 Metal removal efficiency using activated carbon.

Metal	Initial concentration (ppm)	Remaining concentration in aqueous solution (ppm)	pH	Removal efficiency (%)
Cd	4.00	3.347	3.00	16.32
		3.644	5.30	8.90
		2.495	7.30	37.62
Pb	5.00	2.883	3.00	42.34
		2.387	5.30	52.26
		1.768	7.30	64.64
Zn	5.00	3.761	3.00	24.78
		4.105	5.30	17.90
		3.702	7.30	25.96
Cu	5.00	2.866	3.00	42.68
		1.381	5.30	72.38
		0.124	7.30	97.52
		0.167	8.50	96.66
		0.542	11.00	89.16

Table 1 pH values of solutions having highest metal removing efficiency.

Metal	pH
Cd	7.30
Pb	11
Zn	11
Cu	8.50

Table 5 Comparison of metal removing efficiency by dithiocarbamate ligands and activated carbon at temp. 26 °C and for 5 min time period.

Metal (concn., ppm)	pH	Aliphatic ligand efficiency (%)	Aromatic ligand efficiency (%)	Activated carbon efficiency (%)
Cd (4 ppm)	3.00	0.00	85.22	16.38
	5.30	86.72	87.72	8.90
	7.30	65.70	87.97	37.62
	8.50	86.02	87.45	48.40
	11.00	86.35	87.30	50.14
Pb (5 ppm)	3.00	88.82	88.92	42.34
	5.30	49.94	81.44	52.26
	7.30	51.18	86.96	64.64
	8.50	75.60	88.24	89.80
	11.00	94.86	93.40	61.44
Zn (5 ppm)	3.00	75.20	88.56	24.78
	5.30	50.14	82.64	17.90
	7.30	70.46	95.38	25.96
	8.50	67.46	94.08	41.36
	11.00	95.52	95.76	74.30
Cu (5 ppm)	3.00	98.00	98.04	42.68
	5.30	95.42	96.00	72.38
	7.30	98.42	98.60	97.52
	8.50	96.68	99.98	96.66
	11.00	91.50	93.10	89.16