Removal of hexavalent chromium from electroplating wastewaters using marine macroalga Pelvetia canaliculata as natural electron donor

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Fabíola V. Hackbarth (Author) Other; Danielle Maass (Author) Other; Antônio Augusto U. de Souza (Author) Other; Vítor J. P. Vilar (Author) FEUP; Selene M. A. Guelli U. de Souza (Author) Other

Journal

Title: Chemical Engineering Journal

Vol. 290

Pages: 477-489

ISSN: 1385-8947

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 26 Citations

ISI Web of Science

Scopus - 42 Citations

INSPEC

Scientific classification

CORDIS: Technological sciences > Technology > Environmental technology

FOS: Engineering and technology > Environmental engineering

Associated Projects

LSRE-LCM - Laboratório de Processos de Separação e Reação - Laboratório de Catálise e Materiais

ALGAEVALUE - Valorização de macroalgas marinhas na separação e recuperação de iões metálicos tóxicos presentes em água

Other information

Authenticus ID: P-00K-4SZ

DOI: 10.1016/j.cej.2016.01.070

Abstract (EN): This paper reports a treatment strategy for an electroplating wastewater containing high amounts of hexavalent and trivalent chromium and zinc, and residual iron. The brown macroalga Pelvetia canaliculata was used as a natural electron donor for the reduction of Cr(VI) to Cr(III) at acidic pH, and as a natural cation exchanger for zinc, iron and trivalent chromium sequestration. The strategy adopted for the wastewater treatment involves: (i) the reduction of Cr(VI) to Cr(III) using the macroalga as electron donor; (ii) trivalent chromium, zinc and iron precipitation at pH 8.5; and (iii) the removal of residual zinc ions (13 mg/L) by cation exchange at pH 8.5, using the negatively charged functional groups present at the surface of P. canaliculata. The Cr(VI) reduction was evaluated as a function of the biomass and Cr(VI) concentration, pH and temperature. The reaction was promoted through biomass oxidation in acidic medium. The Cr(VI) reduction capacities of raw and protonated P. canaliculata were around 1.8 and 2.3 mmol/g and the values for the Cr (III) uptake capacity of the oxidized biomass were 0.8 and 1.9 mmol/g, respectively. The results suggest that the oxidation of the biomass during Cr(VI) reduction generates new negatively charged active sites for cation binding. The continuous treatment of the wastewater containing Cr(VI) was evaluated in a column packed with raw P. canaliculata, and a maximum Cr(VI) reduction capacity of around 2.1 mmol/g was achieved. After the Cr(VI) removal step, 100% (below the detection limit) and 95% of the remaining trivalent chromium and zinc, respectively, can be eliminated by precipitation at pH 8.5.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13