The present disclosure provides a method for synthesizing fibrous silica nanospheres, the method can include, in sequence, the steps of: a) providing a reaction mixture comprising a silica precursor, a hydrolyzing agent, a template molecule, a cosurfactant and one or more solvents; b) maintaining the reaction mixture under stirring for a length of time; c) heating the reaction mixture to a temperature for a length of time; d) cooling the reaction mixture to obtain a solid, and (e) calcinating the solid to pro duce fibrous silica nanospheres, wherein desirable product characteristics such as particle size, fiber density, surface area, pore volume and pore size can be obtained by controlling one or more parameters of the method. The present disclosure further provides a method for synthesizing fibrous silica nanospheres using conventional heating such as refluxing the reactants in an open reactor, thereby eliminating the need for microwave heating in a closed reactor or the need for any pressure reactors.

This invention is directed to amorphous and crystalline titanosilicate materials that have an unexpected selectivity for cesium and strontium, especially in the presence of high levels of competing ions. The titanosilicates of this invention show very high, unexpected selectivity in the presence of such competing cations such as sodium, calcium, magnesium and potassium, such as present in seawater.

The present invention relates to a zeolite absorbent comprising at least one FAU zeolite with hierarchical porosity and comprising barium or barium and potassium, and the external surface area of which is greater than 20 m.sup.2.Math.g.sup.−1, and the non-zeolite phase content being between 6% and 12% by weight with respect to the total weight of the absorbent. The present invention also relates to the use of such a zeolite absorbent as an adsorption agent, as well as the method for separation of para-xylene from aromatic isomer fractions with 8 carbon atoms.

The present invention refers to the method for synthesis an absorbent material consisting of a phase of tetravalent manganese feroxyhyte (δ-Fe.sub.(1-x)Mn.sub.xOOH) with a negatively charged grain surface in which a percentage of iron has been isomorphically substituted by manganese atoms at 0.05-25%. Its' production is carried out in two continuous flow stirred-tank reactors arranged in serial configuration, where mild acidic conditions (pH 5-6) prevail in the first reactor and mild alkaline conditions (pH 9-10) together with high redox potential (600-700 mV) in the second reactor. The material can be used to uptake mercury, as well as other heavy metals from both water and hot gas streams. Specifically, the adsorption capacity is determined by the magnitude of the negative surface charge and the isoelectric point that can be both adjusted by the synthesis process parameters.

A filter medium is provided with a layer (A) provided with non-impregnated active carbon, a layer (B) with a solid carrier material that is impregnated with a permanganate salt, and a layer (C) with alkaline impregnated active carbon. The layer (B) and the layer (C) are arranged such that a gas flowing through the filter medium flows through the layer (B) before flowing through the layer (C). The layer (A) is arranged such that the gas flowing through the filter medium flows through the layer (A) before flowing through the layer (B) or the gas flowing through the filter medium flows through the layer (A) after flowing through the layer (C).

Provided is a method of purifying a monomer composition that contains a polycyclic aromatic vinyl compound including at least two monocycles selected from the group consisting of aromatic hydrocarbon monocycles and aromatic heteromonocycles. The purification method includes an impurity removal step of removing at least sulfur from the monomer composition.

The present invention relates to an adsorbent comprising an alumina support and at least one alkali element, said adsorbent being obtained by introducing at least one alkali element, identical to or different from sodium, onto an alumina support the sodium content of which, expressed as Na.sub.2O equivalent, before the introduction of the alkali element or elements, is comprised between 1000 and 5000 ppm by weight with respect to the total weight of the support. The invention also relates to processes for the preparation of said adsorbent and use thereof in a process for the elimination of acidic molecules such as COS and/or CO.sub.2.

The invention relates to a method for separating meta-xylene from C8 aromatic fractions, using a zeolitic adsorbent based on sodium-exchanged or sodium-and-lithium-exchanged agglomerated crystals of zeolite Y, with a large external surface area.

Compositions containing a porous organic polymer and a heavy metal chelating moiety are provided for binding heavy metals, for example in remediation and purification. The compositions can be stable and recyclable. The compositions can contain heavy metal chelating moieties such as a thiol, a sulfide, an amine, a pyridine, or a combination thereof. The compositions can bind heavy metals such as lead, cadmium, and mercury. The compositions can have a large surface area greater than about 20 m.sup.2/g. The compositions can be used for remediation and purification to remove heavy metals from a solution. The compositions can have a maximum metal uptake capacity of more than 500 mg g.sup.−1 and/or a metal distribution coefficient of at least 1×10.sup.7 mL g.sup.−1 at 1 atm and 296 K. Methods of making the compositions are provided. Methods of binding heavy metals in remediation and purification are also provided.

The present invention is directed to a method of removing uranium from a uranium containing aqueous medium. The method comprises a step of contacting the medium with magnetic mesoporous silica nanoparticles. The nanoparticles comprise mesoporous silica and iron oxide. The nanoparticles may also comprise a functionalized surface obtained by grafting or covalently bonding a functional molecule to the nanoparticle.