Next Article in Journal
Plasma Enabled Fe2O3/Fe3O4 Nano-aggregates Anchored on Nitrogen-doped Graphene as Anode for Sodium-Ion Batteries
Next Article in Special Issue
Development of Porous Titania Structure with Improved Photocatalytic Activity: Response Surface Modeling and Multi-Objective Optimization
Previous Article in Journal
A Novel Biocompatible Titanium–Gadolinium Quantum Dot as a Bacterial Detecting Agent with High Antibacterial Activity
Previous Article in Special Issue
Photoexcitation Processes in Oligomethine Cyanine Dyes for Dye-Sensitized Solar Cells—Synthesis and Computational Study
Open AccessArticle

Photocatalytic Reduction of Cr(VI) in the Presence of Humic Acid Using Immobilized Ce–ZrO2 under Visible Light

1
Department of Chemistry, University of Torino, Via P.Giuria 7, 10125 Torino, Italy
2
LiqTech International A/S, Industriparken 22 C, 2750 Ballerup, Denmark
3
Chemical Engineering Department, Federal University of Minas Gerais, Av.Antônio Carlos 6627, 30000-000 Belo Horizonte, Brazil
*
Author to whom correspondence should be addressed.
Nanomaterials 2020, 10(4), 779; https://doi.org/10.3390/nano10040779
Received: 27 March 2020 / Revised: 10 April 2020 / Accepted: 16 April 2020 / Published: 18 April 2020
Cr(VI) has several industrial applications but it is one of the most dangerous pollutants because of its carcinogenicity and high toxicity. Thus, the removal of Cr(VI) by photocatalytic reduction was investigated. The catalyst applied, Ce–ZrO2, was immobilized, through a sol–gel process on a silicon carbide (SiC) support, to increase the efficiency and avoid using suspended nanoparticles. The influence of initial pH, humic acid (HA), and catalyst dosage was investigated for Cr(VI) containing solutions. Then, a real galvanizing industry effluent (Cr(VI) = 77 mg L-1mg.L−1, Zn = 1789 mg L−1) was treated. It was observed that Cr(VI) adsorption and photoreduction are greatly favored at low pH values. HA can decrease Cr(VI) adsorption but also acts as holes scavenger, reducing the electron–hole recombination, favoring then the photoreduction. With the immobilized Ce–ZrO2, more than 97% of Cr(VI) was removed from the diluted effluent. These results indicate the feasibility to treat Cr(VI) effluents even in the presence of other metals and natural organic matter. The developed material has great chemical and mechanical resistances and avoids the use of nanoparticles, dangerous for the environment and hard to recover. Moreover, solar light can be used to drive the process, which contributes to the development of more sustainable, cleaner, and cost-effective wastewater treatments. View Full-Text
Keywords: hexavalent chromium; photocatalysis; zirconia; humic acid; photoreduction; zinc; natural organic matter; catalyst immobilization hexavalent chromium; photocatalysis; zirconia; humic acid; photoreduction; zinc; natural organic matter; catalyst immobilization
Show Figures

Graphical abstract

MDPI and ACS Style

Bortot Coelho, F.E.; Candelario, V.M.; Araújo, E.M.R.; Miranda, T.L.S.; Magnacca, G. Photocatalytic Reduction of Cr(VI) in the Presence of Humic Acid Using Immobilized Ce–ZrO2 under Visible Light. Nanomaterials 2020, 10, 779.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop