UV-Assisted Digestion of Petrochemical Industry Effluents Prior to the Determination of Zn, Cd, Pb and Cu by Differential Pulse Anodic Stripping Voltammetry

Domingos, Daniela; Ferreira Neta, Maria de Lourdes S.; Massa, Ana Rosa C. G.; Reboucas, Marcio V.; Teixeira, Leonardo S. G.

doi:10.5935/0103-5053.20160039

Acessibilidade / Reportar erro

Brasil

Journal of the Brazilian Chemical Society

Español English

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Articles • J. Braz. Chem. Soc. 27 (9) • Sept 2016 • https://doi.org/10.5935/0103-5053.20160039 copy

UV-Assisted Digestion of Petrochemical Industry Effluents Prior to the Determination of Zn, Cd, Pb and Cu by Differential Pulse Anodic Stripping Voltammetry

Authorship SCIMAGO INSTITUTIONS RANKINGS

A petrochemical effluent is usually a matrix of very high complexity and composition variability, requiring robust and suitable methods for routine analysis. In this paper, the feasibility of applying a voltammetric technique for the determination of metals species in the petrochemical industry effluent was demonstrated after UV-assisted digestion procedure. Voltammetric (electrolyte volume, deposit time, pulse time, pulse amplitude and scan rate) and digestion variables (hydrogen peroxide volume, nitric acid volume and digestion time) were studied using a 2-level factorial design. The developed voltammetric method using anodic stripping voltammetry (ASV) presented limits of quantification of 11, 5, 15 and 5 µg L⁻¹ for Zn, Cd, Pb and Cu, respectively, and was effective to analyze petrochemical effluents after UV-digestion.

Keywords:
petrochemical effluent; voltammetry; determination of metals; experimental design; ultraviolet-digestion

Experiment	Order	HNO₃ / µL	H₂O₂ / µL	time / s	C_residual / (mg L^-1)	Zn / (mg L^-1)
1	5	0	0	30	1435	1.18
2	1	100	0	30	1742	1.33
3	7	0	50	30	1736	1.28
4	3	100	50	30	1197	1.31
5	4	0	0	120	1756	0.71
6	9	100	0	120	< LOQ	1.32
7	6	0	50	120	786	1.30
8	2	100	50	120	1905	1.35
9	11	50	25	75	725	1.34
10	8	50	25	75	848	1.35
11	10	50	25	75	884	1.36

Experiment	Order	Volume of electrolyte / mL	Deposition time / s	Pulse time / s	Pulse amplitude / mV	Sweep rate / (V s^-1)	Zn / (mg L^-1)	Cd / (mg L^-1)	Pb / (mg L^-1)	Cu / (mg L^-1)	Sum
1	10	0.5	20	0.02	20	0.03	0.487	0.458	0.439	0.484	1.868
2	15	9.5	20	0.02	20	0.03	0.466	0.461	0.464	0.490	1.881
3	5	0.5	160	0.02	20	0.03	0.469	0.460	0.428	0.484	1.841
4	18	9.5	160	0.02	20	0.03	0.203	0.184	0.296	0.172	0.855
5	3	0.5	20	0.06	20	0.03	0.447	0.432	0.432	0.448	1.760
6	7	9.5	20	0.06	20	0.03	0.454	0.474	0.494	0.495	1.918
7	21	0.5	160	0.06	20	0.03	0.410	0.458	0.443	0.477	1.789
8	33	9.5	160	0.06	20	0.03	0.455	0.470	0.468	0.492	1.886
9	8	0.5	20	0.02	70	0.03	0.467	0.450	0.431	0.465	1.813
10	23	9.5	20	0.02	70	0.03	0.378	0.490	0.493	0.471	1.832
11	28	0.5	160	0.02	70	0.03	0.358	0.400	0.424	0.485	1.667
12	1	9.5	160	0.02	70	0.03	0.434	0.463	0.470	0.485	1.852
13	31	0.5	20	0.06	70	0.03	0.479	0.460	0.440	0.476	1.855
14	14	9.5	20	0.06	70	0.03	0.472	0.456	0.473	0.469	1.870
15	25	0.5	160	0.06	70	0.03	0.398	0.463	0.446	0.473	1.779
16	29	9.5	160	0.06	70	0.03	0.414	0.487	0.463	0.484	1.848
17	35	0.5	20	0.02	20	0.09	0.482	0.460	0.484	0.477	1.902
18	12	9.5	20	0.02	20	0.09	0.484	0.421	0.427	0.442	1.775
19	11	0.5	160	0.02	20	0.09	0.485	0.491	0.467	0.447	1.891
20	17	9.5	160	0.02	20	0.09	0.382	0.264	0.479	0.434	1.559
21	26	0.5	20	0.06	20	0.09	0.485	0.468	0.464	0.496	1.914
22	2	9.5	20	0.06	20	0.09	0.398	0.473	0.454	0.483	1.807
23	13	0.5	160	0.06	20	0.09	0.396	0.480	0.449	0.477	1.802
24	27	9.5	160	0.06	20	0.09	0.446	0.461	0.450	0.466	1.822
25	34	0.5	20	0.02	70	0.09	0.490	0.483	0.460	0.496	1.929
26	19	9.5	20	0.02	70	0.09	0.454	0.460	0.491	0.487	1.893
27	16	0.5	160	0.02	70	0.09	0.408	0.453	0.460	0.477	1.797
28	9	9.5	160	0.02	70	0.09	0.435	0.473	0.485	0.496	1.889
29	6	0.5	20	0.06	70	0.09	0.485	0.473	0.467	0.490	1.916
30	30	9.5	20	0.06	70	0.09	0.463	0.466	0.462	0.486	1.878
31	20	0.5	160	0.06	70	0.09	0.378	0.466	0.450	0.463	1.757
32	24	9.5	160	0.06	70	0.09	0.414	0.488	0.495	0.486	1.884
33 (CP)^a a CP: Central point.	32	5.0	90	0.04	45	0.06	0.471	0.460	0.468	0.478	1.877
34 (CP)^a a CP: Central point.	4	5.0	90	0.04	45	0.06	0.472	0.460	0.481	0.481	1.893
35 (CP)^a a CP: Central point.	22	5.0	90	0.04	45	0.06	0.496	0.436	0.445	0.452	1.829

Sample	Zinc / (mg L^-1)		Copper / (mg L^-1)
Sample	ICP OES	Voltammetry	ICP OES	Voltammetry
1	1.75 ± 0.02	1.75 ± 0.06	0.02 ± 0.01	0.022 ± 0.002
2	1.78 ± 0.01	2.26 ± 0.07	0.01 ± 0.01	< 0.005
3	0.34 ± 0.01	0.28 ± 0.01	0.02 ± 0.01	0.032 ± 0.003
4	0.66 ± 0.01	0.76 ± 0.05	0.02 ± 0.01	0.014 ± 0.001
5	0.27 ± 0.01	0.36 ± 0.04	0.02 ± 0.01	0.020 ± 0.002
6	0.35 ± 0.01	0.42 ± 0.06	0.02 ± 0.01	< 0.005
7	0.32 ± 0.01	0.41 ± 0.01	< 0.01	< 0.005
8	0.16 ± 0.01	0.20 ± 0.02	0.03 ± 0.01	< 0.005
9	0.67 ± 0.03	0.80 ± 0.03	< 0.01	0.010 ± 0.001
10	0.66 ± 0.01	0.62 ± 0.02	0.03 ± 0.01	0.028 ± 0.003
11	0.75 ± 0.01	0.75 ± 0.02	0.01 ± 0.01	0.012 ± 0.001
12	0.46 ± 0.01	0.52 ± 0.01	0.02 ± 0.01	0.024 ± 0.002
13	0.67 ± 0.01	0.63 ± 0.02	0.02 ± 0.01	0.024 ± 0.002
14	0.63 ± 0.01	0.64 ± 0.07	0.02 ± 0.01	0.018 ± 0.002
15	0.67 ± 0.01	0.62 ± 0.04	0.02 ± 0.01	0.021 ± 0.002
16	1.10 ± 0.01	0.99 ± 0.11	0.02 ± 0.01	0.013 ± 0.001
17	0.68 ± 0.01	0.61 ± 0.05	0.02 ± 0.01	0.021 ± 0.002
18	1.60 ± 0.01	1.87 ± 0.02	< 0.01	0.017 ± 0.001

Sociedade Brasileira de Química Instituto de Química - UNICAMP, Caixa Postal 6154, 13083-970 Campinas SP - Brazil, Tel./FAX.: +55 19 3521-3151 - São Paulo - SP - Brazil
E-mail: office@jbcs.sbq.org.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *e-mail: lsgt@ufba.br