Simultaneous Bioremediation of Arsenic and Chromium from Soil Using Bacteria: Assessment of Plant Growth, Chlorophyll, and Effects of Extraction Medium

Arsenic and chromium have been known to cause a wide range of health problems, including cancer. This study focused on the removal of arsenic and chromium(VI) from contaminated soil using two bacteria, Pseudomonas aeruginosa strain K7Pb and Prоteus alimentоrum strain ТY6. Arsenic was extracted from soil using CаCl2, distilled water (DW), and aqua regia (AR), whereas NaOH, DW, and AR were used for the extraction of Cr(VI). Plant growth, chlorophyll content, and metal(loid) uptake were also evaluated. For arsenic, CaCl2 was the most effective extraction agent, with a maximum efficiency of 61.82 ± 2.47% for As(III) and 64.18 ± 3.21% for As(V). For Cr(VI), NaOH showed the highest removal efficiency, with maximum values of 54.54 ± 2.73% and 56.06 ± 2.80% for TY6 and K7Pb, respectively, after 15 days. The removal efficiency in this study was defined as the original concentration minus the total arsenic or chromium extracted from the contaminated soil matrix and subsequently transferred to and detected in the aqueous phase. The results revealed that both bacteria can be effectively used for the removal of arsenic and Cr(VI) from soil and may also promote plant growth.