Basaleh Abdullah, Hassan Amjed, Tawabini Bassam, Mahmoud Mohamed, Alghamdi Fahad, Althubiti Abdulmogni, Alrayaan Muhammad, Al-Nasser Rayan
Geosciences Department, College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum & Minerals (KFUPM), P.O. Box 5070, Dhahran 31261, Saudi Arabia.
Center for Integrative Petroleum Research, College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum & Minerals (KFUPM) institution, P.O. Box 5070, Dhahran 31261, Saudi Arabia.
ACS Omega. 2024 Dec 26;10(1):509-519. doi: 10.1021/acsomega.4c06974. eCollection 2025 Jan 14.
Methyl tertiary-butyl ether (MTBE) and BTEX (benzene, toluene, ethylbenzene, and xylenes) are common groundwater contaminants that pose significant health risks. This study investigated the efficiency of a colloidal activated carbon (CAC) material in removing MTBE and BTEX from contaminated water using batch and continuous core flooding systems. In the batch system, a mixture of sand and carbonate was coated with 1-3 g of CAC for the removal of contaminants. The core flooding system was packed with similar materials and mixed with 10 g of CAC. X-ray diffraction (XRD) revealed that the carbonate consists of more than 97% calcite, with traces of clay and quartz minerals. On the other hand, the sandstone sample showed around 89% quartz, 8% clay minerals, and traces of feldspar. The CAC has a surface area of 1050 m/g, mean particle size of 31.8 μm, density of 1.0976 (g/cm), viscosity of 24.4 mPa·s, and a negative surface charge. Spiked water samples with 2000 ppb MTBE and BTEX concentrations ranging between 1000 and 200 ppb were injected through the system at rates of 0.5 and 1.0 mL/min. The results showed that the type of packing materials and flow rate have a significant impact on contaminant removal. For example, the removal efficiency was higher in sandstone due to uniform particle shapes facilitating better water distribution and CAC accessibility within the pore medium. A lower injection rate (0.5 mL/min) resulted in higher removal efficiencies due to increased contact time between contaminants and CAC. At 1 mL/min, the maximum removal of 94% and 65% for MTBE and benzene was achieved in carbonate, while 99% and 96% were achieved in sandstone, respectively. At 0.5 mL/min, complete MTBE removal and over 95% benzene removal were achieved in both materials. Overall, the CAC demonstrated excellent MTBE and BTEX removal capabilities, exceeding 95%, offering a promising approach for in situ groundwater remediation.
甲基叔丁基醚（MTBE）和BTEX（苯、甲苯、乙苯和二甲苯）是常见的地下水污染物，会带来重大健康风险。本研究使用间歇式和连续岩心驱替系统，研究了一种胶体活性炭（CAC）材料从受污染水中去除MTBE和BTEX的效率。在间歇式系统中，用1 - 3克CAC包覆沙子和碳酸盐的混合物以去除污染物。岩心驱替系统填充了类似材料并与10克CAC混合。X射线衍射（XRD）显示，碳酸盐中方解石含量超过97%，还有微量的粘土和石英矿物。另一方面，砂岩样品中石英含量约为89%，粘土矿物含量为8%，还有微量长石。CAC的表面积为1050平方米/克，平均粒径为31.8微米，密度为1.0976（克/立方厘米），粘度为24.4毫帕·秒，且表面带负电荷。将MTBE浓度为2000 ppb以及BTEX浓度在1000至200 ppb之间的加标水样以0.5和1.0毫升/分钟的流速注入系统。结果表明，填充材料类型和流速对污染物去除有显著影响。例如，砂岩中的去除效率更高，因为其颗粒形状均匀，有利于在孔隙介质中更好地分布水以及使CAC更易接触到污染物。较低的注入流速（0.5毫升/分钟）由于污染物与CAC之间的接触时间增加，导致去除效率更高。在流速为1毫升/分钟时，碳酸盐中MTBE和苯的最大去除率分别达到94%和65%，而砂岩中分别达到99%和96%。在流速为0.5毫升/分钟时，两种材料中MTBE均实现完全去除，苯的去除率超过95%。总体而言，CAC表现出优异的MTBE和BTEX去除能力，超过95%，为原位地下水修复提供了一种有前景的方法。
