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Remediation of Selenium-Polluted Soils and Waters by Phytovolatilization
Published in Norman Terry, Gary Bañuelos, of Contaminated Soil and Water, 2020
Adel Zayed, Elizabeth Pilon-Smits, Mark deSouza, Zhi-Qing Lin, Norman Terry
Selenate is the highly bioavailable form of soluble Se that is most commonly found in soils and subsurface drainage waters. Selenate is believed to be taken up and assimilated by the enzymes of the sulfate assimilation pathway. Metabolism of Se through this pathway leads to the formation of Se analogs of the S-containing amino acids (e.g., selenocysteine, selenocystathionine, selenohomocysteine, and selenomethionine). There is evidence that Se analogs of S compounds compete for various enzymes in the S-assimilation pathway. Ng and Anderson (1978) demonstrated that selenide inhibits the synthesis of cysteine and sulfide inhibits the synthesis of selenocysteine. Dawson and Anderson (1988) showed that the enzyme cystathionine γ-synthase (which catalyzes the synthesis of cystathionine from cysteine) has a greater affinity for selenocysteine than for cysteine. McClusky et al. (1986) found that the enzyme cystathionine β-lyase (which catalyzes the production of homocysteine from cystathionine) metabolizes selenocystathionine with a similar affinity to cystathionine. Figure 4.1 summarizes the possible steps in the assimilation pathway for selenate in Se nonaccumulator plants. Details of this pathway are given elsewhere (Terry and Zayed, 1994).
Detoxification of exogenous selenate in cadmium-contaminated soil with pak choi
Published in Gary Bañuelos, Zhi-Qing Lin, Dongli Liang, Xue-bin Yin, Selenium Research for Environment and Human Health: Perspectives, Technologies and Advancements, 2019
M.X. Qi, M.K. Wang, Y. Liu, N.N. Liu, Q.T. Dinh, D.L. Liang*
Selenium (Se) is not essential for plant growth but it can stimulate plant growth, improve the quality of agricultural products at low dose, and also alleviate a variety of environmental pressures, including heavy metal accumulation. At higher concentrations, Se can be used as oxidant and cause damage to plants (Saidi et al. 2014). In contrast, studies have demonstrated that the addition of Se is also a safe and effective way to reduce the accumulation of Cd in plants (Gao et al. 2018, Zhao et al. 2019, Rahman et al. 2019). Bian et al. (2018) showed that Se application in Cd-contaminated soil can increase biomass production and reduce the absorption of Cd in peanuts. Selenate is commonly used in biofortification strategies because of its availability for absorption by plants. Therefore, the aim of this study was to explore the possible detoxification ability of selenate in native Cd-contaminated soil.
Delftia lacustris under aerobic conditions
Published in Shrutika Laxmikant Wadgaonkar, Novel bioremediation processes for treatment of seleniferous soils and sediment, 2018
Growth was routinely monitored by measuring absorbance at 600 nm using UV-Vis spectrophotometry (Shimadzu UV-2501 PC, Groningen, Netherlands). The samples were filtered through a 0.22 μm syringe filter and analysed for selenate, selenite and lactate. Selenite was analysed by UV-Vis spectrophotometry using ascorbic acid reagent (Mal et al., 2016). Selenate was measured by an ion chromatograph equipped with AS14A 3 mm analytical column (Dionex ICS series AS-DV, USA) using 8 mM sodium carbonate and 1 mM sodium bicarbonate as eluant with a flow rate of 0.5 mL min−1 (Dessì et al., 2016). The retention time for selenate was 8.5 min.
The occurrence, transformation and control of selenium in coal-fired power plants: Status quo and development
Published in Journal of the Air & Waste Management Association, 2022
Shuangchen Ma, Fang Xu, Dao Qiu, Shuaijun Fan, Ruimin Wang, Yang Li, Xiangyang Chen
In the desulfurization wastewater treatment industry, chemical precipitation is the most commonly used method because of its reliability and low price. For this method, the wastewater flows through three series tanks for neutralization, precipitation, and flocculation. This method is also called “three-linked tanks” Zou et al. (2020). It can remove most heavy metals (such as mercury, lead, chromium) and suspended solids. In terms of selenium pollution control, because of the low reactivity of selenate, the removal effect of chemical precipitation on selenate is weak. Selenite has higher reactivity and can be removed with higher efficiency. Zhong et al. (2011) Therefore, chemical precipitation treatment of selenium-containing wastewater in the WFGD system is a simple treatment method for high selenite. In other cases, since the effect of removing selenium is unsatisfactory, it is more suitable as a pretreatment.
Biogenic synthesis: a sustainable approach for nanoparticles synthesis mediated by fungi
Published in Inorganic and Nano-Metal Chemistry, 2023
Anuj Chauhan, Jigisha Anand, Vipin Parkash, Nishant Rai
Selenium (Se0) is an insoluble metalloid that can be synthesized biologically and chemically. Selenium is considered to be a promising alternative to selenite (Se+4) and selenate (Se+2) due to its lower toxicity.[64] Vetchinkina et al.[65] reported that Lentinula edodes, a medicinal mushroom can be used to synthesize spherical nanoparticles using inorganic and organic compounds. Macrofungi such as Pleurotus ostreatus, Ganoderma lucidum, and Grifila frondosa also possess the capability of formation of NPs by cultivation on selenium (Na2SeO3) and germanium (GeO2) containing media.
DFT analysis of the active site in catalytic metabolic redox reactions of mononuclear molybdenum enzymes
Published in Journal of Coordination Chemistry, 2018
This reduction is associated with the respiratory electron transfer chains that generate an electro-chemical gradient across the cytoplasmic membrane of bacteria [14, 16]. Selenate is the oxidized form of selenium which is highly soluble and can present significant hazards to health and the environment (Supplementary Material, figure S1) [17].