(279c) Recovery of High-Value Elements from Produced Water Using Ligand Modified Silica Nanoparticle

Recent advances in crude oil production have unlocked significant petroleum reserves, and the amount of produced water (PW) generated with it has increased dramatically. Oil and gas production in Oklahoma alone generates over 100,000 acre-feet per year of PW. Data from the Oklahoma Corporation Commission (OCC) indicate that nearly 3 billion barrels of PW in Oklahoma were injected into the earth in 2017. Deep injection has led to increased seismicity and other issues in several regions of the world. PW has various valuable elements including lithium (Li), cobalt (Co), iodine (I) and rare earth elements (REE) including lanthanum (La), neodymium (Nd), and europium (Eu). These elements are critical materials for numerous technologies including consumer electronics, automotive, energy, and defense. PW is an attractive potential source for REE and lithium production. This work seeks to develop an adsorbent that is capable of removing these valuable elements from aqueous systems. Hydrophilic silica nanoparticles were modified using N-[(3-trimethoxysilyl) propyl] ethylenediamine triacetic acid (TMS-EDTA). This modified silica was used for the adsorption and separation of these valuable elements from aqueous solutions. The presence of the EDTA on the surface of the nanoparticles was confirmed using FTIR. Batch studies were conducted to determine the adsorption capacity, effect of pH, temperature, dosage and kinetics of adsorption. The mechanism of adsorption would be verified using existing models along with the kinetics of adsorption and thermodynamic parameters.