A silicon-modified zinc oxide material, wherein the silicon-modified zinc oxide material (i) has a BET surface area of at least 50 m.sup.2/g, (ii) has a Si:Zn atomic ratio in the range of 0.001 to 0.5:1 and (iii) is in the form of a shaped unit selected from a pellet, extrudate or granule, or a wash-coat on a monolith support. The silicon-modified zinc oxide material has improved resistance to thermal sintering and may be used as a catalyst or sorbent material.

Disclosed herein are transition and/or heavy metal cation-capturing membranes constructed from zinc imidazole salicylaldoxime (ZIOS) nanosheets deposited on membrane supports, and methods of making and using such metal cation-capturing membranes. In a non-limiting embodiment, the membrane support comprises polyvinylidene fluoride (PVDF) membranes which have been modified with polydopamine (PDA) and polyethyleneimine (PEI). Three exemplary methods for fabricating the metal cation-capturing membranes include (1) in-solution hydrothermal growth, (2) vacuum-assisted coordination growth, and (3) interfacial coordination growth methods. The membranes may be tuned regarding textural properties and the adhesion of the ZIOS to the membrane support.

Disclosed herein are composite materials and methods of making and use thereof. The composite materials comprise: a carbon nanotube and a plurality of ferrihydrite particles disposed on the carbon nanotube, the composite material comprising the plurality of ferrihydrite particles and the carbon nanotube in a weight ratio of from 5:95 to 95:5. The weight ratio can be selected such that the composite material has a desired balance between specific surface area and specific capacitance. Also disclosed herein are methods comprising: making a plurality of the composite materials, the weight ratio of the plurality of ferrihydrite particles and the carbon nanotube being different for each composite material; and determining and comparing the specific surface area and specific surface capacitance for the plurality of composite materials to determine the weight ratio at which the composite material has a desired balance between the specific surface area and the specific capacitance.

A method of oxidizing a component of an aqueous medium is provided. The method includes adding an effective amount of an oxidizing composition to the aqueous medium. The oxidizing composition includes an ingredient, such as hydrogen peroxide, a percarbonate salt, a peroxy compound, a chlorite or alkali metal salt thereof, a chlorate or alkali metal salt thereof, or any combination thereof. The method also includes oxidizing the component. The component may be a metal, a mineral, a microbial metabolite, an organic molecule, or combination thereof. The method also includes modulating the application of the oxidizing composition based on a measured aqueous medium parameter.

A method of removing a contaminant from water may include contacting contaminated water, including a heavy metal and/or an organic pollutant, with a nanocomposite including graphitic C.sub.3N.sub.4, MnO.sub.2, and MgAl.sub.2O.sub.4 in a mass relationship to each other in a range of from 5 to 15:2 to 7:75 to 95, thereby adsorbing the heavy metal and/or the organic pollutant onto the nanocomposite, as an adsorbed material. The method may further include removing the adsorbed material from the contaminated water, thereby reducing a concentration of the heavy metal in the contaminated water by at least 2 percent by weight (wt. %), the heavy metal may include Cd, Cr, Cu, Fe, Pb, Ni, Ag, Zn, and/or U, and the organic pollutant may include a dye.

A method of treating water to remove selenium and/or mercury that is dissolved in the water. The method includes adding an acid to the water to reduce the pH, adding a metal reagent to the water that is effective to reduce the selenium and/or mercury to a lower oxidation state, and then removing the reduced selenium and/or mercury from the water.

A method of separating and recovering a cobalt salt and a nickel salt includes a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least both the cobalt salt and the nickel salt as rare metals, in which the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25 C., individually permeate through the nanofiltration membrane at an operating pressure of 0.5 MPa.

Compositions and methods for removing phosphates, nitrates and heavy metals from aqueous solutions.

A highly permeable sorbent platform based on polysulfone and polystyrene-b-poly(acrylic acid) composite membranes. The membranes possess a fully interconnected network of poly(acrylic acid)-lined pores, which enables the surface chemistry to be tailored through sequential attachment of polyethyleneimine moieties and metal-binding terpyridine ligands. The polyethyleneimine moieties increase the saturation capacity, while the addition of terpyridine enables high-affinity binding to a diversity of transition metal ions. This membrane platform removes such metal contaminants from solution. The metal capture performance of the functionalized membranes persists even in high concentrations of competitive ions. Also, fluorescence quenching of the terpyridine moiety upon metal ion complexation offers an in-situ probe to monitor the extent of sorbent saturation. The permeability, capacity, and affinity of these membranes, with high-density display of a metal-binding ligand, offer a chemically tailored platform to address the challenges that arise in ensuring clean water.

An adsorption filter according to the present invention is an adsorption filter including a molded body containing activated carbon and a binder. A pore volume of the adsorption filter at a pore diameter of 15 m or more and 30 m or less at a volume basis of the adsorption filter under measurement by mercury intrusion porosimetry is 0.06 cm.sup.3/cc to 0.30 cm.sup.3/cc.