Controlling metal ion migration in contaminated groundwater with Iraqi clay barriers for water resource protection

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 Pb2+ 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-1 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(-1) 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.

Automated summary

This study examines the effectiveness of using Iraqi clay as a low-permeability layer to prevent the migration of lead and nickel ions in groundwater. Batch operation tests were conducted to determine the ideal conditions for removing Pb2+ and Ni2+ ions. The Langmuir formula was found to be the most effective sorption model, with sorption capacities of 1.75 mg/g for nickel ions and 137 mg/g for lead ions. Finite element analysis simulations showed that the clay barrier created low-discharge zones downstream, reducing the rate of pollutant migration and protecting water sources.