Selenium (Se 79 34) is an essential element in living organisms.It is the 30th most abundant naturally occurring metalloid element on the Earth's crust. Selenium is present in the earth's crust at an estimated amount of 0.05–0.5 mg Se kg − 1 (Lemly, 2004), with total selenium concentrations in rocks amounting to 40% of the total earth's crust …

The whitish–yellow obtained product, i.e., MIL-53 (Fe) was then recovered and used for carrying out all selenium removal experimentation. Selenium removal study Adsorption experiment. About 0.1-mg/mL adsorbent dosage, i.e., 20 mg of MIL-53 (Fe) was ultrasonicated in 200-mL solution with different selenite concentrations. About 7 mL of …

A comprehensive literature review is conducted to analyze various studies that have explored the use of modified biochars, iron oxides, and other non-conventional biosorbents for selenium removal. The assessed biosorbents include biomass, microalgae-based, alginate compounds, peats, chitosan, and biochar/modified biochar …

The wastewaters were used "as received" or pre-treated. Tests ran for about 120 bed volumes with an empty bed contact time (EBCT) of 10-20 minutes. Selenium removal efficiency was highly dependent on the wastewater, ranging from poor removal to removal (see Table). Based on the results of the screening level tests, field pilot tests ...

Here, we review methods for selenium removal from water, wastewater, and industrial effluents. Technologies are based on zero-valent iron, iron-oxy-hydroxides, supported materials, nanofiltration ...

Here, we review methods for selenium removal from water, wastewater, and industrial effluents. Technologies are based on zero-valent iron, iron-oxy-hydroxides, supported materials, nanofiltration ...

Adsorbents as magnetic nanomaterials used for dissolved‑selenium removal were summarized in this review. Section snippets Magnetic nanoparticles. Nanotechnology is a highly concerned technology with fast development [33]. MNPs are nano-scale particles having magnetic properties that facilitate the reuse of the sorbents, which have been ...

Selenium removal from aqueous medium can also be achieved using biological methods. In a first approach, these kinds of methods appear to be attractive, low-cost, and eco-friendly, since few chemicals are required. Biological volatilization can occur in soils, sediments and water. It is based on the natural ability of bacteria, fungi and …

A follow-up pilot-scale study done by Cantafio et al. (1996) used a packed-bed bioreactor inoculated with the bacterium Thauera selenatis for the removal of selenium from the drainage wastewater and achieved a removal rate and performed a complete conversion of selenate to elemental selenium. The removal of selenium was …

Direct electrochemical reduction provides a novel strategy for selenium removal from complex wastewaters. While electrochemical Se(IV) reduction is thermodynamically favorable, anion structure ...

The lack of terms directly related to possible technologies for selenium removal from water during the analysis of the most frequently used keywords was at least partially solved when the cluster Adsorption was examined (Figures S7 and S9). This cluster appeared in the third subperiod (2012–2019) and had continuity until the last …

Anthropogenic-driven selenium (Se) contamination of natural waters has emerged as severe health and environmental concern. Lowering Se levels to safe limits of 40 μg-L −1 (recommended by WHO) presents a critical challenge for the scientific community, necessitating reliable and effective methods for Se removal. The primary …

Several conventional bioreactor systems can be used to remove selenate and selenite from wastewater and form selenium nanoparticles. However, the selenium …

Veolia has developed the Tracer Se process (patent pending), which is a new method for selenium removal based on biological reduction of selenium to selenite, …

Selenium removal from well water (closed due to high selenium concentrations, 0.1 mg/L) by the composite, brought levels to below the WHO limit (0.01 mg/L) and was selective for selenium even in ...

This article outlines 7 health benefits of selenium, all backed by science. 1. Acts as a powerful antioxidant. Antioxidants are compounds in foods that prevent cell damage caused by free radicals ...

First Online: 29 April 2021. 569 Accesses. 10 Citations. Part of the book series: Environmental Chemistry for a Sustainable World ( (ECSW,volume 66)) Abstract. After …

Selenium is used as a paint and varnish remover, and as a solvent for rubber resins and other organic substances. Selenium catalysts, due to their high efficiency, moderate reaction conditions, good functional compatibility and excellent selectivity, have attracted a lot of interest over the past two decades as recently …

The solution to the removal circuit has a typical composition of 100 g/L copper sulfate, 125 g/L sulfuric acid and, reporting at most 100 mg/L of selenium. It was reported by Qin (2005) that 20 to 40% of the selenium to …

The data from another bench-scale test outlines an example of selenium reduction potential from oil refinery wastewater: 24.4 μg/L from untreated wastewater; . 2.5 μg/L from treated wastewater. In many states (California, for example), groundwater is being regulated for selenium discharge, creating challenges for industrial facilities.

Biological reduction of selenium oxyanions is widely used for selenium removal from wastewater. The process is, however, limited by the availability of a suitable, efficient and low cost electron donor. In this study, selenite and selenate reduction by waste activated sludge using hydrogen as the electron donor was investigated.

Selenium removal from wastewater is an issue that many industrial sites trying to achieve discharge requirements must address. Selenium is a naturally-occurring element, however certain industrial activities can elevate selenium levels in both waste and process water. These activities include mining, refining, coal combustion, and other ...

The Se removal efficacy can be enhanced by: 1) Combining biological treatment with chemical or physical methods to optimize Se removal and to ensure …

The Se removal efficacy can be enhanced by: (i) reorienting the future research focus towards novel techniques effective specifically towards overcoming the reduction competition among ions (by pretreatment of inhibiting species and/or Se …

Recently, sorption processes have been successfully used for selenium removal. The operating cost for media and maintenance for sorption processes may be high and should be considered in the life ...

An MBBR is a biological method to remove selenium that can operate with the same support material for over 20 years, while granulated activated carbon in other biological methods may need to be replaced regularly. The MBBR does not require back-washing; it can tolerate high suspended solids concentrations in the feed and is not …

Here, we review methods for selenium removal from water, wastewater, and industrial effluents. Technologies are based on zero-valent iron, iron-oxy-hydroxides, supported materials, nanofiltration ...

Selenium Removal for Electrical Utilities. SeQuester can be employed to remove selenite and selenate from power plant flue gas desulfurization (FGD), ash-sluicing, ash pond, and landfill leachate wastewaters. It also reduces the concentration of other priority pollutants in these water streams under standard operating parameters.

In selenium water treatment, selenite and selenate are reduced to insoluble selenium that is removed along with biomass and feed suspended solids by downstream liquid/solids separation. This process is effectively used for selenium removal from mining wastewater and other difficult industrial applications.

Schematic of dissolved‑selenium removal using nano-magnetic particles. 2.1. Nanosized zero-valent iron (nZVI) Zero-valent iron (ZVI) is a ubiquitous substance in nature, which can be used as a removal agent for a variety of pollutants [38, 39].

The removal of selenium from superficial and waste water is a worldwide problem. The maximum limit according to the World Health Organization (WHO) for the selenium in the water is set at a concentration of 10 μg/L. Carbon based adsorbents have attracted much attention and recently demonstrated promising performance in removal …

An iron coprecipitation unit at the industrial scale. This technology is a well-known and well-accepted chemical process for the removal of metals and metalloids, including the removal of selenium and arsenic, and has been widely implemented in various industries; briefly, a ferric salt is added to the effluent, forming an amorphous iron oxyhydroxide precipitate; …

Current industrial efforts for selenium removal are mainly based on biological and chemical approaches, whereas physical methods (e.g., nanofiltration and reverse osmosis) have not captured much ...

Integration of microalgae with nanoparticles used in the removal of chromium and selenium metal ions was discussed in the present review with the removal mechanism. The economic perspectives, advantages and challenges of using the integral magnetic microalgal system in the treatment process were also evaluated in the present …

For this purpose, a batch airlift reactor with air stirring was used. The sacial electrodes were made of iron to generate the necessary ferrous ions for the process. The results indicated a selenium removal of 90% from the wastewater after 6 h of treatment, achieving a decrease in concentration from 0.30 mg L-1 to 0.03 mg L-1. The …

USBR investigated selenium removal technologies from 2003 to 2006. Investigations included laboratory bench-testing and field pilot-testing to reduce selenium concentrations in local agricultural drainage water near Firebaugh, California. USBR issued a Record of Decision in 2007, which selected a drainage alternative based upon a reverse ...

Technologies based on zero-valent iron, iron-oxy-hydroxides, supported materials, nanofiltration, reverse osmosis, chitosan-enhanced ultrafiltration, electrodialysis, and …

Moreover, bioreactor configurations and operation strategies greatly influence the selenium removal and recovery efficiency. Several conventional bioreactor systems can be used to remove selenate and selenite from wastewater and form selenium nanoparticles. However, the selenium nanoparticles are mostly entrapped in the …