Open Access

ARTICLE

Treatment of Agate Dyeing Wastewater Using an Immobilized Gel Mixture with Nano-Fe₃O₄ Sulfate-Reducing Bacteria

by Xuying Guo^1,*, Guoliang Jiang², Saiou Fu³, Zhiyong Hu³, Junzhen Di², Yanrong Dong², Ying Li⁴

1 College of Science, Liaoning Technical University, Fuxin, 123000, China
2 College of Construction Engineering, Liaoning Technical University, Fuxin, 123000, China
3 College of Mining Engineering, Liaoning Technical University, Fuxin, 123000, China
4 Liaoning Fourth Geological Team Limited Liability Company, Fuxin, 123000, China

* Corresponding Author: Xuying Guo. Email:

Journal of Renewable Materials 2021, 9(11), 2015-2032. https://doi.org/10.32604/jrm.2021.015878

Received 20 January 2021; Accepted 02 March 2021; Issue published 04 June 2021

Abstract

To solve the problems of high Cr⁶⁺, Cr³⁺, SO₄^2– and H⁺ concentrations, pollution and processing costs associated with agate dyeing industrial drainage, we prepared an immobilized gel mixture for the treatment of such drainage on the basis of microbial immobilization technology. The immobilized gel mixture was composed of sulfate-reducing bacteria (SRB), corn cob, and nano-Fe₃O₄ (nFe₃O₄). We used a single-factor experiment to determine the optimal dose of each matrix component. We analyzed the mechanism underlying the treatment of agate dyeing wastewater with an immobilized gel mixture by X-ray diffraction and scanning electron microscopy detection. The results of the single-factor test showed that the best treatment was obtained under the following conditions for each matrix component: SRB mass percentage of 30%, nFe₃O₄ dose of 3%, and corn cob mesh size of 100 and dose of 3%. On this basis, we conducted an L₉(3⁴ ) orthogonal experiment to determine the optimal proportion of each matrix component. The results showed that the best treatment was obtained when the gel mixture met the following conditions: SRB mass percentage of 40%, nFe₃O₄ dose of 4%, and corn cob dose of 1% and mesh size of 100. Accordingly, the SO₄^2– , Cr⁶⁺ and Cr³⁺ removal rates from the agate dyeing drainage were 70.54%, 84.75%, and 73.80%, respectively; the total Fe and chemical oxygen demand releases were 1.086 mg·L^–1 and 1104 mg·L^–1 , respectively; and the pH was 6.27. The gel mixture had the best treatment effect on agate dyeing wastewater under this composition ratio.

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