Acid Mine Drainage Remediation: Aluminum Chelation Using Functional Graphenic Materials

Abstract

Acid mine drainage (AMD) is a pervasive source of metal pollution that severely impacts freshwater ecosystems and has a direct impact on human health. Conventional active and passive methods work very well for removing iron in AMD remediation, which is typically the highest metallic impurity. However, conventional passive remediation fails to remove all aluminum, which has severe ecological implications. Removal of aluminum ions using chelation, which traditionally uses small molecules that bind metals tightly for sequestration, holds promise. Yet, chelation strategies are limited because once introduced into surface water, small molecules are difficult to reclaim and often persist in the environment as pollutants. To address this, we have designed six unique scaffolds based on functional graphenic materials (FGMs) to create nonsoluble materials that could be placed at the end of a passive remediation process to remove persistent aluminum. When tested for efficacy, all six FGMs successfully demonstrated a reversible capacity to remove aluminum from acidic water, chelating up to 21 μg of Al/mg of FGM. Furthermore, when they were exposed to E. coli as an approximation for environmental compatibility, viability was unaffected, even at high concentrations, suggesting these FGMs are nontoxic and viable candidates for passive chelation-based remediation.

Functionalization of Silica Nanoparticles by 5-Chloro-8-quinolinol as a New Nanocomposite for the Efficient Removal and Preconcentration of Al3+ Ions from Water Samples

“…Found Concentration (Practically) Total Concentration (Theoretically) 100 (12) In addition, % RSD (relative standard deviation) was determined by eq 13.…”

“…In the literature, various procedures for extraction and preconcentration of aluminum prior to analysis, such as liquid–liquid extraction, co-precipitation, single-drop microextraction, cloud point extraction, and solid-phase removal, have been defined. − Solid-phase removal was employed for the extraction of numerous kinds of contaminants from aqueous solutions since it provides many advantages, such as easy operation, high selectivity, cheap cost, minimal time, and the ability to be combined with various modern detection techniques . Recently, some adsorbents were used for the removal and preconcentration of aluminum ions from aqueous solutions, such as Linde type-A zeolite, magnetic activated carbon/tungsten nanocomposite, iron-modified activated carbons, cellulose modified with gallic acid, montmorillonite, spent mushroom substrate, functional graphene materials, bio-sorbents derived from the stems of plants, activated carbon, natural zeolite, and polymeric resins. − In recent years, the fabrication of eco-friendly and green adsorbents with high separation capacities for harmful metal ions has posed a significant challenge to the control of environmental pollution. − In this regard, Bulgariu and Bulgariu synthesized a novel adsorbent via the functionalization of soy waste biomass by an industrial sulfur-based chelating agent for the removal of Pb­(II), Cu­(II), and Ni­(II) ions from aqueous media . Nowadays, silica is a widely utilized adsorbent with multiple uses in separation processes.…”

A simple, cost-effective colorimetric assay for aluminum ions via complexation with the flavonoid rutin

“…1A) and other flavonoids makes it uniquely equipped to chelate metals. As a ligand, rutin features weakly acidic phenol moieties that bind metal ions to form acid-stable complexes (Tristantini & Amalia, 2019;Jomova et al, 2019;Karpinsky et al, 2020). In the case of rutin, phenols on ring B (Pekal & Pyrzynska, 2014; Kasprzak, Erxleben & Ochocki, 2015;Jomova et al, 2019) and the phenol and keto group on rings A and C, (Pekal & Pyrzynska, 2014;Kasprzak, Erxleben & Ochocki, 2015;Tristantini & Amalia, 2019;Jomova et al, 2019) respectively, are potential sites for chelation.…”