Design of a fixed-bed ion-exchange process for the treatment of rinse waters generated in the galvanization process using Laminaria hyperborea as natural cation exchanger

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

Authors

Vítor J. P. Vilar (Author) FEUP; Luciana P. Mazur (Author) Other; Tatiana Pozdniakova (Author) Other; Diego A. Mayer (Author) Other; Rui A. R. Boaventura (Author) FEUP

Journal

Title: Water Research

Vol. 90

Pages: 354-368

ISSN: 0043-1354

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 9 Citations

ISI Web of Science

Scopus - 22 Citations

Scientific classification

CORDIS: Technological sciences > Technology > Environmental technology

Associated Projects

LA 20 - PROJECTO ESTRATÉGICO - LA 20 - 2013-2014

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-24E

DOI: 10.1016/j.watres.2015.12.027

Abstract (EN): In this study, the removal of zinc from galvanization wastewaters was performed in a fixed bed column packed with brown macro-algae Laminaria hyperborea, acting as a natural cation exchanger (resin). The rinse wastewater presents a zinc concentration between 9 and 22 mg/L, a high concentration of light metals (mainly Na and Ca), a high conductivity (0.5-1.5 mS/cm) and a low organic content (DOC = 7 -15 mg C/L). The zinc speciation diagram showed that approximately 80% of zinc is in the form of Zn2+ and congruent to 20% as ZnSO4, considering the effluent matrix. From all operational conditions tested for zinc uptake (17 < bed height <27 cm, 4.5 < flow rate < 18.2 BV/h, 0.8 < particle equivalent diameter < 2.0 mm), the highest useful capacity (7.1 mg Zn/g algae) was obtained for D/dp = 31, LID = 11, 9.1 BV/h, tau = 6.4 min, corresponding to a service capacity of 124 BV (endpoint of 2 mg Zn/L). Elution was faster and near to 100% effective using 10 BV of HCl (1 M, 3.0%, 363 g HCl/L of resin), for flow rates higher than 4.5 BV/h. Calcium chloride solution (0.1 M) was selected as the best regenerant, allowing the reuse of the natural resin for more than 3 saturation/elution/regeneration cycles. The best operation conditions were scaled-up and tested in a pre-pilot plant. The scale-up design of the cation exchange process was proposed for the treatment of 2.4 m(3)/day of galvanization wastewater, resulting in an estimated reactants cost of 2.44 (sic)/m(3).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15