Removal of Uranium from Effluent Acidic Solution Using Manganese Oxide Coated Modified Talc (MOCMT)

Research Article

Austin Chem Eng. 2023; 10(2): 1101.

Removal of Uranium from Effluent Acidic Solution Using Manganese Oxide Coated Modified Talc (MOCMT)

MS Nagar*; KF Mahmoud; WM Yousef; AA Abdou

Nuclear Materials Authority, El Maadi, Cairo, Ehypt

*Corresponding author: MS Nagar Nuclear Materials Authority, PO Box 530, El Maadi, Cairo, Egypt. Email: [email protected]

Received: July 03, 2023 Accepted: August 11, 2023 Published: August 18, 2023

Abstract

In this study, the unique manganese dioxide coated modified talc (MOCMT) adsorbent was easily synthetic. (MOCMT) was evaluated as an adsorbent for the removal of U (VI) from effluent (=10 ppm) solution. To fit the adsorption results, the Langmuir and Freundlich isotherm models were applied, as well as the kinetic parameters of the adsorption process, which were measured and fitted. Five adsorption/desorption cycles with 0.3 M H2SO4 as an eluent were performed to test the reusability. The MOCMT was used to extract uranium from effluent solution produced after a four-cycle leaching/adsorption during the uranium milling process in the Gattar project.

Keywords: Uranium; Manganese dioxide; Talc; Adsorption

Introduction

Uranium is a naturally occurring radioactive element that has been mined and used for over a thousand years for its chemical properties. It is presently largely used as a fuel for electricity-generating nuclear reactors. Uranium is a non-degradable element with high fluidity and a lengthy history of chemical and biological contamination. Some uranium will enter the body through drinking water and the food chain, accumulating primarily in the liver, kidney, and bone [1]. Chemical poisoning and internal radiation will induce a variety of acute and chronic disorders [2]. The WHO has set a maximum contaminant value of 9μg L-1 for uranium, and the US EPA has set a recommended value of 30μg L-1 for a U (VI) maximum concentration limit in drinking water [3]. As a result, removing uranium from waste has become a pressing and vital issue for environmental and human health protection.

Several studies have been carried out to remove uranium from nonconventional sources such as seawater, industrial effluent, and other wastes [4-8]. On the other hand, the nuclear industry's activities have released excessive amounts of uranium into the environment [9]. For many years, uranium's toxicity has been a public health concern [10]. As a result, uranium must be removed, recovered, concentrated, and purified in order to meet future energy demand and avoid radioactive contamination of the environment. The removal of U (VI) ions from aqueous solutions has been reported using a variety of treatment approaches. Because it is environmentally acceptable, easy to purify, generally available, and highly efficient [11,12], the sorption process of U(VI) onto different solid materials has been thoroughly researched [13-16].

Due to their great removal capabilities for harmful ions for environmental remediation, nanostructured materials in environmental treatment have recently gained a lot of attention due to they introduce new functions that are absent for bulk materials [17-22].

Few investigations have been done on the adsorption properties of U(VI) in talc. Mg3Si4O10(OH)2 is the chemical formula for talc. It is made up of three layers: a magnesium hydroxide layer (MgOH2O) sandwiched between two silicate layers (SiO2) [23]. The platy structure of talc is created by weak van der Waals interactions connecting adjacent layers. The talc surfaces' low-energy silicate layers, [001] crystal domains, are hydrophobic, but the edges showing hydroxyl groups (–SiOH) and (–MgOH) are more hydrophilic [24,25]. It is clear that surface adsorption has a significant effect. Furthermore, specific surface functional groups of talc, such as Si-O-Si and O-Si-O, can bind with heavy metal ions and aid in the removal of heavy metal ions from talc [26]. In the manufacturing of paints, lubricants, plastics, cosmetics, medicines, and ceramics, talc is extensively employed as a filler, coating, and dusting agent [27].

Unmodified talc has been used in the chemical adsorption processes of many elements, and among these processes is the use of talc in the adsorption of heavy elements from water by Yunfeng Xu [28] investigated the adsorption of divalent lead ions in water using talc. According to studies, talc has a high rate of Pb2+ adsorption in lead-contaminated wastewater. In batch adsorption studies, Myroslav Sprynskyy et al., [29] investigated the adsorption of uranium in aqueous solution by talc. The study reveals that uranium adsorbs on talc in large clusters or molecules. Yunfeng Xu and colleagues [30] employed talc in their study of nickel-containing waste water adsorption in water, and they explored the impacts optimum conditions on nickel adsorption onto talc.

When talc is modified, its specific surface area can be raised to enhance the active functional group, and some features can be added, allowing the modified talc to be utilised for a variety of applications. Hannatu Abubakar Sani et al [31] used ZnO nanoparticles to modify talc to create ZnO/talc nanocomposites to examine the adsorption efficacy of Pb(II) in aqueous solution. According to the findings, ZnO/talc nanocomposites have a high adsorption capability. Cu(II), Ni(II), and Pb(II) ions were removed from aqueous solutions using Fe3O4/talc nanocomposites. The initial concentrations of heavy metal ions Cu (II), Ni (II), and Pb (II) were 100, 92, and 270 mg/L, respectively, according to the results [32]. To efficiently remove lead (II) and nickel (II) from aqueous solutions, a new polysulfone/Fe3O4-talc nanocomposite hybrid matrix membrane was used [33].

Through adsorption and co-precipitation processes, hydrous manganese oxides usually play a key role in limiting trace metal concentrations. They have a huge surface area, a microporous structure, and a high affinity for metal ions, which makes them an efficient heavy metal scavenging pathway [34]. Because manganese dioxide occurs in the form of fine particles, it is difficult to separate solids from liquids, making it unsuitable as a filtering medium [35]. Its doping on solid support will improve its ability to separate metal ions; for example, under column testing, manganese dioxide coated zeolite was employed to remove uranium (VI), copper (II), and lead (II) [36,37]. Table 1 summaries published results on the adsorption of various cations by manganese dioxide coated onto various sorbents [38-47].