Polymer-clay composites were designed to adsorb selenium from water. The highest adsorption efficiency was obtained for chitosan-montmorillonite composites. These composites were characterized by XRD, zeta potential, and FTIR measurements. Adsorption isotherms of selenate on the composite, on Al-oxide and on Fe-oxide were in good agreement with the Langmuir model, yielding a somewhat higher capacity for the composite, 18.4, 17.2 and 8.2 mg/g, respectively. In addition, adsorption by the composite was not pH dependent while its adsorption by the oxides decreased at high pH. 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 the presence of sulfur (13 mg/L). Selenium adsorption by the composite was higher than by the Al-oxide due to high adsorption of sulfur by the later. Unlike employment in batch Al-oxide is more suitable for employment in filtration columns due to its high hydraulic conductivity. A semi-pilot columns experiment demonstrated selenium removal from the well water below the recommended limit (first 400 pore volumes) by Al-oxide columns. Regeneration of Al-oxide and of the composite was studied and readsorption of selenium was demonstrated.
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http://dx.doi.org/10.1016/j.jhazmat.2010.07.065 | DOI Listing |
Molecules
January 2025
College of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045, China.
To address cadmium pollution in China's cultivated land, chitosan, inorganic and organic selenium were used to modify rice husk charcoal for cadmium inhibition. Basic physicochemical properties of rice husk carbons were characterized (BET, FTIR, XRD, Zeta potential). Kinetic and isothermal adsorption experiments studied the adsorption of Cd by modified biochar under different pH and dosages.
View Article and Find Full Text PDFJ Environ Manage
January 2025
BQE Water, Vancouver, BC, Canada.
Biological semi-passive mine water treatment technologies are used in the mining industry as an alternative to or in conjunction with active treatment systems to remediate mine impacted water (MIW) containing nitrate and selenium oxyanions such as selenate and selenite. In semi-passive biological treatment systems, MIW is pumped through a saturated, porous media (either a gravel bed or waste rock) which provides ample surface area for biofilm growth and the creation of anoxic, subaqueous environments. Additional nutrients and carbon sources are pumped into the system to encourage the growth of microbes that biochemically reduce selenate and selenite to insoluble reduced Se species such as selenium nanoparticles (SeNP) by respiring selenate and selenite.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China; College of Chemical Engineering and Technology, Yantai Nanshan University, Yantai 265713, China. Electronic address:
The contamination of water resources by selenium (Se), particularly in the highly toxic Se(IV) oxidation state, poses a significant environmental and public health concern due to its detrimental impacts on humans and aquatic ecosystems. In this work, we report a novel composite foam (CFC) by incorporating chitosan (CS), cellulose nanofibers (CNF) and iron oxyhydroxide (FeOOH) nanoparticles through a one-pot fabrication process. The CFC foam features a three-dimensional porous structure, conferring both exceptional mechanical strength and superior adsorption performance for Se(IV), with a maximum equilibrium adsorption capacity of 90 mg/g achieved within 3 h.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
The development of cost-effective point-of-use (POU) devices that effectively remove lead (Pb) from drinking water is imperative in mitigating the threat of Pb contamination to public health in underdeveloped regions. Herein, we have successfully transformed inexpensive natural kaolinite as hydroxy-sodalite (HySOD) via a simple hydrothermal process, achieving an impressive yield of 91.5 %.
View Article and Find Full Text PDFJ Control Release
January 2025
State Key Laboratory of Food Science and Resources, China-Canada Joint Lab of Food Science and Technology (Nanchang), Key Laboratory of Bioactive Polysaccharides of Jiangxi Province, Nanchang University, Nanchang 330047, China.
Selenium deficiency associated with a high risk of many diseases remains a global challenge. Owing to the narrow margin between "nutrition-toxicity" doses of selenium, it is imperative to achieve accurate selenium supplement. Nano‑selenium (SeNPs) is a novel form of selenium supplement with low toxicity, but it could be trapped and removed by intestinal mucus, thus limiting its oral delivery.
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