Enhanced bioleaching efficiency of vanadium from stone coal vanadium ore by adding biochar and plasma treatment

To address the common problem of low vanadium bioleaching efficiency from stone coal, different enhanced bioleaching methods were used in this study. In the single enhancement treatment of adding biochar, plasma pretreatment, and adding sodium dodecyl sulfate (SDS), the addition of 1 g of biochar had the best effect on vanadium leaching by Bacillus mucilaginosus (B. mucilaginosus), with a 9.8% higher vanadium leaching rate compared to the blank group. While, the compound enhanced treatment method, including plasma treatment of stone coal for 6 min and adding 0.1 g/L biochar in bioleaching system, can further improve vanadium leaching. At 20 days of bioleaching, the vanadium leaching rate was 21.7% higher than that of the blank group. It was found that biochar can facilitate bacterial attachment through microbial immobilization and increase bacterial biomass. The flourier transform infrared (FTIR) spectroscopy results show that the plasma pretreatment can introduce oxygen-containing functional groups such as hydroxyl and carboxyl groups to modify the surface of the stone coal, which reduced the contact angle of the stone coal by 22.1 degrees and improved its surface hydrophilicity and reactivity, enhancing the interface reaction between B. mucilaginosus and stone coal vanadium ore. Hence, this work significantly promoted the vanadium bioleaching performance through compound enhanced bio-leaching mothed, which appears very promising for the development of practical applications.

Automated summary

To improve the efficiency of vanadium bioleaching from stone coal, this study explored different enhanced bioleaching methods. Results showed that adding 1 g of biochar had the best effect on vanadium leaching, with a 9.8% higher leaching rate compared to the control group. A compound enhanced treatment method including plasma treatment and the addition of 0.1 g/L biochar further improved vanadium leaching, with a 21.7% higher leaching rate compared to the control group. The use of biochar facilitated bacterial attachment and the plasma pretreatment modified the surface of stone coal to enhance the reaction between bacteria and vanadium ore.