Environmental Impacts of Selenium Contamination: A Review on Current-Issues and Remediation Strategies in an Aqueous System

Abstract

In both aquatic and terrestrial environment, selenium contamination may exist at concentrations above the micronutrient limit. Since there is such a narrow bandwidth between which selenium concentration is acceptable, the health of the public may be at risk of selenium toxicity once the concentration increases beyond a threshold. Selenium contamination in an aqueous environment can occur due to anthropogenic activities and/or from natural sources. This study presents a review of the forms of selenium, inorganic and organic selenium contamination, mobilization, analytical methods for various forms of selenium and remediation strategies. The review also provides recent advances in removal methods for selenium from water including bioremediation, precipitation, coagulation, electrocoagulation, adsorption, nano-zerovalent iron, iron co-precipitation and other methods. A review of selenomethionine and selenocysteine removal strategy from industrial wastewaters is presented. Selenium resource recovery from copper ore processing has been discussed. Various analytical methods used for selenium and heavy metal analysis were compared. Importantly, existing knowledge gaps were identified and prospective areas for further research were recommended.

Microbe–Mineral Interaction-Induced Microorganism-Augmented Permeable Reactive Barriers for Remediation of Contaminated Soil and Groundwater: A Review

“…Selenium (Se) is an essential nutrient . It is used in ceramics, metallurgy, glass industries, and other industries . Se is beneficial in reducing heart disease, maintaining the normal function of the heart, and preventing cancer .…”

“…95 It is used in ceramics, metallurgy, glass industries, and other industries. 96 cancer. 95 However, it becomes toxic at high concentrations and may cause brain diseases and cancer.…”

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

“…It is not included in the European Commission's Dangerous Substance Directive's list of substances of concern. Moreover, among 41 chemicals that are subject to Environmental Quality Standards in Europe, Se is not included (Okonji et al, 2021 ). The US Se guidelines for marine waters allow a maximum concentration of 300 g/L and a continuous concentration of 71 g/L, despite planned revisions.…”

Biofortification of Horticultural Crops With Selenium

“…Amount of Se vary in soils and depends upon various factors like type of soil, organic matter, and rainfall (Sors et al 2005). Natural and anthropogenic activities are responsible for addition of selenium in environment (Winkel et al 2012;Tan et al 2016;Okonji et al 2021). Natural activities like volcanic eruptions, forest fires and soil erosion and anthropogenic activities like burning of fossil fuels, plastics, rubbers, and paper etc.…”