在碳化合物污染的含水层中,活性升高
Amy K Wiersma1, Glen Hook2, Madeleine Mathews3
1Environmental Chemistry and Technology Program, Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Environmental science & technology
|June 7, 2023
概括
碳化合物泄漏可以通过改变含水层的地质化学来增加地下水中的 (Ra). 铁和的减少过程与高的Ra活动有关,突出显示了污染地点微量元素监测的必要性.
科学领域:
- 环境科学 环境科学
- 地质化学 地质化学
- 水文地质学 水文地质学
背景情况:
- 地下碳化合物泄漏会改变水表地质化学,形成生物地质化学区域.
- 这些区域,包括铁 (Fe ((III)) 和 (Mn ((III/IV)) (氧化水减少),可以调动地质污染物.
- (Ra) 同位素 (226Ra,228Ra) 是自然存在的放射性核酸,在地下水中引起关注.
研究的目的:
- 在受碳化合物泄漏影响的含水层中调查活动.
- 确定碳化合物污染,生物地化学条件和动员之间的关系.
- 评估辐射在受污染的含水层中的运输和运输.
主要方法:
- 利用多层监测系统测量地下水中的活动.
- 分析了含水层的地化学参数,包括pH值,总溶解固体和氧化还原条件.
- 采用地化学建模来理解分离机制.
主要成果:
- -226 (226Ra) 活动高达背景水平的10倍,距离源区60米的下降辐射.
- 较高的Ra活性与较低的pH值,较高的总溶解固体和甲原性条件相关.
- Fe和Mn (水氧) 氧化物的降解和吸位的竞争被确定为增加Ra的可能驱动因素.
- 在Fe (III) /SO42-减少区,Ra活动恢复到了600米下降的背景水平.
- 地化学模型表明,对二级矿物阶段 (例如,粘土) 的吸附对于Ra封存至关重要.
结论:
- 碳化合物污染对水层中的行为产生重大影响.
- 生物地质化学过程,特别是Fe和Mn的减少,影响的调动和减弱.
- 虽然Ra活动低于饮用水标准,但较高的水平强调了监测碳化合物影响地区微量元素的重要性.
- 吸附到二级阶段在保持在含水层内起着关键作用.
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