On November 22, Professor Ye Hengpeng from the School of Resources and Environmental Science published his latest research inWater Research, titled “Effect of sulfate-reducing bacteria (SRB) and dissimilatory iron-reducing bacteria (DIRB) coexistence on the transport and transformation of arsenic in sediments” (https://doi.org/10.1016/j.watres.2024.122834). Sun Yan, a graduate from South-Central Minzu University and now a Ph.D. student at Huazhong University of Science and Technology, is the first author. Professor Ye Hengpeng and Assistant Researcher Lan Jirong from The Hong Kong Polytechnic University are the corresponding authors, with South-Central Minzu University as the primary institution.
According to the paper, the dissolution and release of arsenic in sediments are major causes of high-arsenic groundwater. The migration and transformation of arsenic are influenced by groundwater redox conditions, coexisting ions, iron and manganese oxides, and microbial activity. This paper investigates the mechanisms of arsenic migration and transformation in sediments under the synergistic regulation of two key microorganisms: sulfate-reducing bacteria (SRBs) and dissimilatory iron-reducing bacteria (DIRBs). The study reveals the patterns of arsenic migration and transformation by SRB and DIRB alone and in combination, particularly elucidating complex environmental chemical processes in groundwater systems, such as groundwater-microbe-iron/sulfur mineral transformation-arsenic migration (Figure 1).
Figure 1. Mechanism of Arsenic Migration and Transformation in Sediments Mediated by SRB and DIRB.
The research identifies three distinct stages in the arsenic release process. In the first stage, mixed bacteria significantly promote the release of arsenic and iron, affecting the behavior of As(V) in the subsequent stages. In the second stage, interactions among mixed bacteria significantly hinder the synthesis of sulfate reductase, reducing the formation of secondary iron minerals and arsenic fixation. In the third stage, mixed microbes secrete large amounts of organic acids to counteract toxic substances, leading to the decomposition of iron oxides and the release of adsorbed arsenic. These findings explain the complex interactions between DIRBs and SRBs within bacterial communities and clarify their synergistic role in inducing arsenic migration and transformation. The results are significant for understanding arsenic cycling in sediments and can help mitigate arsenic release and reduce related environmental risks by adjusting the concentration and activity of SRB or DIRB.
Water Researchis one of the two most prestigious and influential international journals in environmental science and engineering, recognized by the Nature Index, and ranked in the top tier (Q1) by the Chinese Academy of Sciences with an impact factor of 11.4. It is classified as an A-level journal by the university. In recent years, leveraging strengths in chemistry, materials, and engineering, the university has consistently published high-quality papers in environmental and ecological sciences, significantly advancing the discipline into the top 1% globally in ESI rankings and enhancing its academic standing and international influence.
