Faisal Ayad A H, Al-Ridah Zaid Abed, Al-Ansari Nadhir, Hassan Waqed H, Al-Hashimi Osamah, Ghfar Ayman A, Hashim Khalid
Department of Environmental Engineering, College of Engineering, University of Baghdad Baghdad Iraq
College of Engineering, Al-Qasim Green University Babylon Iraq
RSC Adv. 2023 May 30;13(24):16196-16205. doi: 10.1039/d3ra01773g.
This study investigates the effectiveness of using Iraqi clay as a low-permeability layer to prevent the migration of lead and nickel ions in groundwater-aquifers. Tests of batch operation have been conducted to determine the optimal conditions for removing Pb ions, which were found to be 120 minutes of contact time, a pH of 5, 0.12 g of clay per 100 mL of solution, and an agitation of 250 rpm. These conditions resulted in a 90% removal efficiency for a 50 mg L initial concentration of lead ions. To remove nickel ions with an efficiency of 80%, the optimal conditions were 60 minutes of contact time, a pH of 6, 12 g of clay per 100 mL of solution, and an agitation of 250 rpm. Several sorption models were evaluated, and the Langmuir formula was found to be the most effective. The highest sorption capacities were 1.75 and 137 mg g for nickel and lead ions, respectively. The spread of metal ions was simulated using finite element analysis in the COMSOL multiphysics simulation software, taking into account the presence of a clay barrier. The results showed that the barrier creates low-discharge zones along the down-gradient of the barrier, reducing the rate of pollutant migration to protect the water sources.
本研究调查了使用伊拉克粘土作为低渗透层来防止铅和镍离子在地下水含水层中迁移的有效性。进行了间歇操作试验以确定去除铅离子的最佳条件，发现接触时间为120分钟、pH值为5、每100 mL溶液中粘土用量为0.12 g以及搅拌速度为250 rpm。对于初始浓度为50 mg/L的铅离子，这些条件下的去除效率达到了90%。为了以80%的效率去除镍离子，最佳条件为接触时间60分钟、pH值为6、每100 mL溶液中粘土用量为12 g以及搅拌速度为250 rpm。评估了几种吸附模型，发现朗缪尔公式最为有效。镍离子和铅离子的最高吸附容量分别为1.75和137 mg/g。在COMSOL多物理场模拟软件中使用有限元分析模拟了金属离子的扩散情况，同时考虑了粘土屏障的存在。结果表明，该屏障在屏障的下坡方向形成了低排放区，降低了污染物的迁移速率，从而保护了水源。
