Migration of l-Selenomethionine in the Water-Soil Interface Dominated by Iron Oxides.

Organic selenium (Se) accounts for up to 10-80% of total Se in soils, and l-selenomethionine (SeMet) is a typical organic Se species. However, the migration of SeMet in soils remains elusive. This study investigated the solid-liquid distribution, adsorption, desorption by phosphate, and self-oxidization of SeMet in solution under the influence of ferrihydrite, goethite, and hematite through batch experiments.

Microbial metabolic limitation of rhizosphere under heavy metal stress: Evidence from soil ecoenzymatic stoichiometry.

Slow nutrient turnover and destructed soil function were the main factors causing low efficiency in phytoremediation of heavy metal (HM)-contaminated soil. Soil ecoenzymatic stoichiometry can reflect the ability of soil microorganisms to acquire energy and nutrients, and drive nutrient cycling and carbon (C) decomposition in HM-contaminated soil. Therefore, for the first time, we used the enzymatic stoichiometry modeling to examine the microbial nutrient limitation in rhizospheric and bulk soil of different plants (Medicago sativa, Halogeton arachnoideus and Agropyron cristatum) near the Baiyin Copper Mine.

Facile fabrication of MOF(Fe)@alginate aerogel and its application for a high-performance slow-release N-fertilizer.

In this work, a novel MOF(Fe)@NaAlg aerogels composite were fabricated by a facile method of ion cross-linking, and characterized via Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS) and BET surface area analysis. The MOF(Fe)@NaAlg aerogels loaded by ammonium (NH) was prepare to the slow-release fertilizer (SRF). The adsorption capacity and swelling of MOF(Fe)@NaAlg(2:10) were 29.

Impact of low-molecular weight organic acids on selenite immobilization by goethite: Understanding a competitive-synergistic coupling effect and speciation transformation.

The interactions between low-molecular weight organic acids (LMWOAs) and selenium (Se) on mineral/water interfaces affect the release, immobilization and bioavailability of Se in nature. Herein, the effects of three environmentally relevant LMWOAs (i.e.

High-quality Al@Fe-MOF prepared using Fe-MOF as a micro-reactor to improve adsorption performance for selenite.

High-quality Al@Fe-MOF was prepared by in situ modification of Fe-MOF with Al to improve the adsorption performance for selenite (Se(Ⅳ)). The structures and properties of Al@Fe-MOF were characterized by powder X-ray diffraction, high resolution transmission electron microscope, X-ray photoelectron spectroscopy (XPS), nitrogen isothermal adsorption-desorption measurement and zeta potential. The adsorption performance of Al@Fe-MOF for Se(Ⅳ) was studied by batch adsorption experiments.

[Interactions between Goethite and Humic Acid and the Stability of Goethite-Humic Acid Complex].

Goethite-humic acid complex was prepared in a suspension containing goethite and humic acid. X-ray diffraction (XRD) results showed that the crystal structure of this complex had no obvious changes compared to pure goethite, but the peak intensity of the complex was slightly reduced. Transmission electron microscopy (TEM) images indicated that the surface of the goethite was coated by particles of humic acid.

[Adsorption Properties of Fluorine onto Fulvic Acid-Bentonite Complex].

Fulvic Acid-Bentonite (FA-BENT) complex was prepared using coprecipitation method, and basic properties of the complex and sorption properties of fluorine at different environmental conditions were studied. XRD results showed that the d₀₀₁ spacing of FA- BENT complex had no obvious change compared with the raw bentonite, although the diffraction peak intensity of smectite in FA-BENT complex reduced, and indicated that FA mainly existed as a coating on the external surface of bentonite. Some functional groups (such as C==O, −OH, etc.

[Adsorption Characteristics for Humic Acid by Binary Systems Containing Kaolinite and Goethite].

In this study, the binary systems of kaolinite-goethite mixture (KGM) and kaolinite-goethite complex (KGC) were prepared by different methods, and the surface properties and humic acid adsorption of the samples were investigated. Results showed that the specific surface area (SSA) of the samples followed the order of goethite> KGC> KGM> kaolinite, and the SSAs increased significantly for KGC while slightly for KGM when compared to the average value of kaolinite and goethite. The isoelectric point (IEP) of kaolinite, goethite, KGM and KGC appeared around 3.

[Surface properties and adsorption characteristics for fluoride of goethite, kaolinite and their association].

The basic properties of goethite, kaolinite and their association were characterized using X-ray diffraction (XRD) , scanning electron microscopes (SEM), Fourier transform infrared spectroscopy (FT-IR), potentiometric titrations, specific surface area (SSA) and micropore analysis. Moreover, the adsorption capacity and adsorption models of fluoride by the investigated samples were studied. Results show that when kaolinite and goethite presented simultaneously in the same suspension system, goethite was apt to coat the surface of kaolinite and the interactions between them could occur rapidly.