Enhanced synergistic mineralization of uranium, arsenic, and cadmium in uranium tailings pond wastewater through bio-oxidation of arsenic (III) by Brevundimonas spp.

Synergistic mineralization is a new remediation method for dealing with multi-metal(loid)s pollutants. Here, a novel remediation strategy of enhanced synergistic mineralization of Uranium (U), Arsenic (As), and Cadmium (Cd) in U tailings pond wastewater through bio-oxidation of As(III) by Brevundimonas spp was proposed. A novel strain of As(III)-oxidizing bacteria ( Brevundimonas ) with highly resistant to U, As, and Cd was isolated. One biological removal test group was set with U-As(III)-Cd (UAs III Cd- Brevundimonas ), and two chemical removal test groups composed of U-As(V)-Cd (UAs V Cd), and U-As(III)-Cd (UAs III Cd), respectively. The results showed that A(V) in the UAs V Cd group could combine with U and Cd to enhance their removal rates and promote synergistic mineralization to form the more stable precipitations (Cd(UO 2 ) 2 (AsO 4 ) 2 ·nH 2 O) compared to As(III). Further, We achieved biological oxidation of As(III) to A(V) by isolated As(III)-oxidizing bacteria Brevundimonas , which contributed to the subsequent synergistic mineralization of U and Cd to form precipitates similar to those in chemical methods (UAs V Cd group), ultimately increasing the removal of U, As, and Cd by 5.90, 2.40, and 6.19 times than without adding Brevundimonas spp. The results will help to design more effective bioremediation strategies for U-As-Cd multi-metal(loid)s contamination. Download: Download high-res image (198KB) Download: Download full-size image