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

本研究的主要目的是系统地确定通过生物和非生物耦合过程动员Cr （III）的潜在途径/机制，并评估其对Cr迁移的相对意义。铬（Cr）是全世界关注的主要污染物，因为它具有致癌性和毒性，并且在许多危险废物场所中普遍存在。Cr在水生环境中常见的氧化态有Cr （VI）和Cr （III）。由于Cr （VI）比Cr （III）更具水溶性和毒性，因此修复工作主要集中在原位还原Cr （VI）到Cr （III）。然而，最近的研究表明，某些自然过程可能氧化和调动Cr (III)，潜在地影响还原性处理的长期稳定性。本项目从以下方面研究了环境中Cr（III）的迁移性：(1)通过非氧化机制调动Cr(III)；(2)锰氧化物氧化活化铬（III）；(3)生物/非生物耦合过程对复杂系统中Cr迁移率的影响。研究结果将有助于环境管理者评估还原处理后Cr的长期稳定性，以及Mn氧化物对地下Cr （III）的氧化是否有助于观察到地下水中Cr （VI）的变化。PI将在实验室培训本科生，并计划在附近的密苏里林肯大学招收代表性不足的少数族裔。林肯大学是1890年授予的一所历史上的黑人学院和大学。

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.