Chromium(III) Oxidation and Mobilization Through Coupled Biotic/Abiotic Processes

CBET-0828411 Deng，Baolin University of Missouri-Columbia该提案的主要目标是通过耦合生物和非生物过程系统地识别Cr（III）动员的潜在途径/机制，并评估其对Cr流动性的相对重要性。铬（Cr）是全世界关注的关键污染物，因为其致癌和有毒的性质以及在许多危险废物场地中的常见情况。水环境中常见的铬氧化态是Cr（VI）和Cr（III）。由于Cr（VI）物种比Cr（III）物种更易溶于水且毒性更大，因此修复工作集中在将Cr（VI）原位还原为Cr（III）。然而，最近的研究表明，某些自然过程可能会氧化和动员铬（III），可能会影响还原处理的长期稳定性。本项目调查了环境中三价铬物种的流动性：（1）通过非氧化机制进行的三价铬流动;（2）通过锰氧化物氧化进行的三价铬流动;生物/非生物耦合过程对复杂系统中铬迁移的影响。研究结果将有助于环境管理者评估长期的长期稳定的铬还原处理后，以及是否铬（III）氧化在地下锰氧化物有助于观察到的铬（VI）在地下水中。PI将在实验室培训本科生，并在附近的密苏里州林肯大学（一所1890年授予土地的HBCU（历史上的黑人学院和大学）机构）为代表性不足的少数民族制定了招聘计划。

CBET- 0828411Deng, Baolin University of Missouri-ColumbiaThe principal objectives of this proposal are to systematically identify potential pathways/mechanisms for Cr (III) mobilization via coupled biotic and abiotic processes and to evaluate their relative significance for Cr mobility. Chromium (Cr) is a key contaminant of concern throughout the world because of its carcinogenic and toxic nature combined with common occurrence at numerous hazardous waste sites. Common Cr oxidation states in the aquatic environment are Cr (VI) and Cr (III). Since Cr (VI) species are more water soluble and toxic than Cr (III) species, remediation efforts have focused on the in-situ reduction of Cr (VI) to Cr (III). However, recent studies indicate that certain natural processes may oxidize and mobilize Cr (III), potentially affecting the long-term stability of reductive treatments. This project investigates the mobility of Cr(III) species in the environment in terms of (1) Chromium(III) mobilization through non-oxidative mechanisms; (2) Chromium(III) mobilization through oxidation by Mn oxides; and (3) Impact of coupled biotic/abiotic processes on Cr mobility in complex systems.Research results will be useful for environmental managers in assessing long-term stability of Cr following reductive treatment and whether Cr (III) oxidation in the subsurface by Mn oxides contributes to the observed Cr (VI) in groundwater. The PI will train undergraduates in the lab and has a recruitment plan for underrepresented minorities at nearby Lincoln University of Missouri, an 1890 land grant HBCU (Historically Black Colleges and Universities) institution.