| Full text | |
| Author(s): |
Kallyni Irikura
[1]
;
Marcelo Braga Bueno Guerra
[2]
;
Nerilso Bocchi
[3]
;
Romeu Cardozo Rocha-Filho
[4]
;
Elaine Kikuti
[5]
;
Sonia Regina Biaggio
[6]
Total Authors: 6
|
| Affiliation: | [1] Universidade Federal de São Carlos. Departamento de Química - Brasil
[2] Black Hills State University. School of Natural Sciences - Estados Unidos
[3] Universidade Federal de São Carlos. Departamento de Química - Brasil
[4] Universidade Federal de São Carlos. Departamento de Química - Brasil
[5] Universidade Federal de Uberlândia. Faculdade de Ciências Integradas do Pontal - Brasil
[6] Universidade Federal de São Carlos. Departamento de Química - Brasil
Total Affiliations: 6
|
| Document type: | Journal article |
| Source: | Química Nova; v. 41, n. 3, p. 340-345, 2018-03-00. |
| Abstract | |
Residual solutions containing Cr(VI) ions can be harmful to the environment as well as to human health. Hence, practical and efficient methods for the treatment of such solutions are welcome. In this note, the treatment with commercial steel wool pads of a Cr(VI) residual solution from electrochemical coloration processes of stainless steel is described in detail. Successful treatment was achieved when an amount of steel wool equivalent to 20% in excess in relation to the theoretical stoichiometric amount was used, followed by chemical precipitation with sodium hydroxide up to pH 10-11 and separation by filtration under reduced pressure. The treatment yielded a final solution with concentrations of Cr(III) and Cr(VI) ions of only 0.29 ± 0.02 mg L-1 and < 0.01 mg L-1, respectively. These concentration values are significantly lower than the maximum limits established by CONAMA for industrial wastewaters, attesting the efficiency of the treatment. (AU) | |