Department of Applied Geosciences, Hydrogeology Research Group, Technische Universität Berlin , 10587 Berlin, Germany.
Environ Sci Technol. 2016 Aug 2;50(15):8028-35. doi: 10.1021/acs.est.6b00335. Epub 2016 Jul 12.
Although karst aquifers are far more susceptible to contamination than porous aquifers, with the transport of particulate matter being an important factor, little is known about the attenuation of solutes within karst aquifers and even less about the attenuation of particulate matter. These in situ investigations have therefore aimed to systematically identify the processes that influence the transport and attenuation of particles within a karst aquifer through multitracer testing, using four different types of 1 μm fluorescent particles and the fluorescent dye uranine. Each of the types of particles used were detected at the observed spring, which drains the investigated aquifer. However, the transport behavior varied significantly between the various particles and the uranine dye, with the breakthrough of particles occurring slightly earlier than that of uranine. Attenuation was determined from the tracer recovery and attributed to filtration processes. These processes were affected by the hydrophobicity and surface charge of the particles. Carboxylated polystyrene particles with a density and surface charge comparable to pathogenic microorganisms were found to be mobile in groundwater over a distance of about 3 km. No attenuation was observed for plain silica particles. Particles with these characteristics thus pose a major threat to karst spring water as they might occur as contaminants themselves or facilitate the transport of other contaminants.
虽然岩溶含水层比多孔含水层更容易受到污染，颗粒物质的传输是一个重要因素，但对于岩溶含水层中溶质的衰减以及颗粒物质的衰减知之甚少。因此，这些现场调查旨在通过使用四种不同类型的 1μm 荧光颗粒和荧光染料尿嘧啶的多示踪剂测试，系统地识别影响岩溶含水层中颗粒传输和衰减的过程。所使用的每种类型的颗粒都在观察到的泉水处被检测到，该泉水排泄着被研究的含水层。然而，各种颗粒和尿嘧啶之间的传输行为差异很大，颗粒的突破时间略早于尿嘧啶。衰减是根据示踪剂的回收来确定的，并归因于过滤过程。这些过程受到颗粒的疏水性和表面电荷的影响。发现具有与致病性微生物相当的密度和表面电荷的羧基化聚苯乙烯颗粒在地下水中能够迁移约 3 公里。普通二氧化硅颗粒没有观察到衰减。具有这些特征的颗粒对岩溶泉水构成了重大威胁，因为它们本身可能是污染物，或者促进其他污染物的传输。
