Radium in hydraulic fracturing wastewater: distribution in suspended solids and implications to its treatment by sulfate co-precipitation
Radium in hydraulic fracturing wastewater: distribution in suspended solids and implications to its treatment by sulfate co-precipitation
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DOI：
10.1039/c8em00311d
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发表时间：
2019-02-01
影响因子：
5.5
通讯作者：
Feng, Xiahong
中科院分区：
文献类型：
--
作者：
Ouyang, Bingjie;Renock, Devon J.;Feng, Xiahong
高浓度的钡（Ba）、锶（Sr）和镭（Ra）存在于水力压裂产生的废水的液体和悬浮固体部分中。这些高浓度通常需要特殊处理，其中固体和液体部分被分离，然后在处置之前被单独处理。固体通常在垃圾填埋场中处置，而液体被进一步处理、回收用于未来的水力压裂或经由注入威尔斯处置。寻找固体和液体组分的最佳处理方法需要彻底了解处理过程中形成的原始悬浮固体和矿物沉淀物的潜在Ra流动性。使用顺序提取程序，我们发现，未经处理，超过50%的Ra-226在悬浮固体与可溶性盐和易交换馏分。当废水的液体部分通过与含有高硫酸盐浓度的酸性矿山排水（AMD）混合来处理时，在混合物溶液中发现约80-97%的总Ra-226存在于沉淀物的不溶性硫酸盐部分中。在沉淀的固体硫酸盐馏分中螯合的Ra-226的活性与废水-AMD溶液的Sr/Ba比正相关。我们讨论了这些研究结果的影响，有效的长期管理的固体和液体废物中的高镭。
High concentrations of barium (Ba), strontium (Sr) and radium (Ra) are present in both the liquid and suspended solid portions of wastewater produced from hydraulic fracturing. These high concentrations often require special treatment in which the solid and liquid portions are separated and then independently treated prior to disposal. The solids are typically disposed in landfills while the liquids are further treated, recycled for future hydraulic fracturing, or disposed via injection wells. Finding optimal treatment methods of both the solid and the liquid fractions requires a thorough understanding of potential Ra mobility from both the raw suspended solids and mineral precipitates formed during treatment. Using a sequential extraction procedure, we found that, without treatment, more than 50% of Ra-226 in the suspended solids was associated with soluble salts and readily exchangeable fractions. When the liquid portion of the wastewater was treated by mixing with acid mine drainage (AMD), which contained high sulfate concentrations, approximately 80-97% of the total Ra-226 in the mixture solution is found in the insoluble sulfate fraction of the precipitate. The activity of Ra-226 sequestered in the precipitated solid sulfate fractions is positively correlated with the Sr/Ba ratio of the wastewater-AMD solution. We discuss implications of these findings for effective long-term management of elevated radium in both solid and liquid wastes.