A critical analysis of sources, pollution, and remediation of selenium, an emerging contaminant

Abstract

Selenium (Se) is an essential metalloid and is categorized as emerging anthropogenic contaminant released to the environment. The rise of Se release into the environment has raised concern about its bioaccumulation, toxicity, and potential to cause serious damages to aquatic and terrestrial ecosystem. Therefore, it is extremely important to monitor Se level in environment on a regular basis. Understanding Se release, anthropogenic sources, and environmental behavior is critical for developing an effective Se containment strategy. The ongoing efforts of Se remediation have mostly emphasized monitoring and remediation as an independent topics of research. However, our paper has integrated both by explaining the attributes of monitoring on effective scale followed by a candid review of widespread technological options available with specific focus on Se removal from environmental media. Another novel approach demonstrated in the article is the presentation of an overwhelming evidence of limitations that various researchers are confronted with to overcome achieving effective remediation. Furthermore, we followed a holistic approach to discuss ways to remediate Se for cleaner environment especially related to introducing weak magnetic field for ZVI reactivity enhancement. We linked this phenomenal process to electrokinetics and presented convincing facts in support of Se remediation, which has led to emerge ‘membrane technology’, as another viable option for remediation. Hence, an interesting, innovative and future oriented review is presented, which will undoubtedly seek attention from global researchers.

Understanding the Effect of Single Atom Cationic Defect Sites in an Al2O3 (012) Surface on Altering Selenate and Sulfate Adsorption: An Ab Initio Study

“…Details for all species present in adsorbed_cell and desorbed_cell for all configurations and protonation are listed in Table S1. We only computed adsorption energies of fully deprotonated oxo anions (SeO 4 2– and SO 4 2– ) as they are the only species present at pH > 2, i.e., all environmentally relevant pHs. , …”

“…) as they are the only species present at pH > 2, i.e., all environmentally relevant pHs. 56,57 For a given configuration ΔE was calculated using eq 1:…”

Selenium volatilization in plants, microalgae, and microorganisms

“…Studies have indicated that the discharge of selenate (Se (Ⅵ)) and selenite (Se (Ⅳ)) into the environment can lead to significant pollution, particularly in terms of water quality [ 2 , [34] , [35] , [36] ]. The presence of Se in water can pose a severe threat to aquatic organisms, wildlife, and humans due to its tendency to accumulate and magnify within the biological system [ [37] , [38] , [39] ], leading to a decrease in fish biomass and drastic changes in population structure [ 33 , 40 , 41 ]. When exposed to high levels of Se for a long time, it can cause toxic reactions including congenital disability, reproductive disorders, liver failure, skin damage, respiratory failure, and hair and nail loss [ [42] , [43] , [44] , [45] , [46] ].…”

Molybdenum-Oxysulfide-Functionalized MgAl-Layered Double Hydroxides─A Sorbent for Selenium Oxoanions

“…8 These activities enable the deposition of selenium into the atmosphere and its subsequent leaching into the aquatic environment. 9 In aquatic systems, selenium mainly remains as soluble oxoanions, such as selenate (Se VI ) and selenite (Se IV O 3 2− ), and is important to remove for the safeguard of biological systems.…”

“…On the other hand, human-related contributions to selenium contamination are mainly linked to industrial activities, such as mining operations and the burning of fossil fuels . These activities enable the deposition of selenium into the atmosphere and its subsequent leaching into the aquatic environment . In aquatic systems, selenium mainly remains as soluble oxoanions, such as selenate (Se VI O 4 2– ) and selenite (Se IV O 3 2– ), and is important to remove for the safeguard of biological systems.…”