A method of removing a metal ion from water is disclosed. The method includes treating the water with a nanocomposite to absorb the metal ion with the nanocomposite, forming a polymer-metal ion composite and removing the polymer-metal ion composite from the water. The nanocomposite includes aluminum oxide dispersed in a matrix of an uncrosslinked graft copolymer that includes a chitosan backbone and side chains of poly(itaconic acid) grafted to the chitosan backbone. The chitosan backbone has a plurality of amino groups that are acetylated by itaconic acid.

The invention relates to a photocatalyst that is active under irradiation with UV light, visible light and sunlight, comprising a powder or a ready-to-use nanometric suspension of nitrogen-doped TiO.sub.2, wherein the brookite crystalline phase is also present and whose doping nitrogen content (% by weight) is sufficient to ensure photocatalytic activity in the visible region. The photocatalyst can be easily applied to substrates of varying nature.

The invention relates to a photocatalyst that is active under irradiation with UV light, visible light and sunlight, comprising a powder or a ready-to-use nanometric suspension of nitrogen-doped TiO.sub.2, wherein the brookite crystalline phase is also present and whose doping nitrogen content (% by weight) is sufficient to ensure photocatalytic activity in the visible region. The photocatalyst can be easily applied to substrates of varying nature.

A method of treating a fluid, which method includes the steps of: (a) contacting a fluid containing at least one sulfide with a sulfide-reducing amount of a composition comprising an lignocellulosic liquor comprising one or more lignin-derived compounds and one or more hemicellulose sugar monomers and/or oligomers and (b) allowing the lignocellulosic liquor to react with at least a portion of the sulfide in the fluid.

Provided herein are methods and compositions for water disinfection. The methods and compositions, which can include a peracid and a source of copper ions, are useful for treatment of water contaminated with recalcitrant microbes.

Provided herein are methods and compositions for water disinfection. The methods and compositions, which can include a peracid and a source of copper ions, are useful for treatment of water contaminated with recalcitrant microbes.

A method of brewing coffee includes the following steps:—requesting a user to select a coffee-based beverage on an input device coupled to a coffee brewing apparatus; selecting a suitable water recipe from a database comprising a plurality of water recipes suited for brewing coffee, wherein the selected water recipe is suited to the selected coffee-based beverage, wherein the water recipe defines a set mineral concentration of brewing water to be prepared; requesting a water preparation unit to prepare a brewing water based on the water recipe, wherein the water preparation unit is adapted to mineralize the brewing water according to the set mineral concentration of the water recipe; preparing brewing water based on the water recipe; and brewing the coffee-based beverage with the brewing water prepared according to the water recipe.

A method of brewing coffee includes the following steps:—requesting a user to select a coffee-based beverage on an input device coupled to a coffee brewing apparatus; selecting a suitable water recipe from a database comprising a plurality of water recipes suited for brewing coffee, wherein the selected water recipe is suited to the selected coffee-based beverage, wherein the water recipe defines a set mineral concentration of brewing water to be prepared; requesting a water preparation unit to prepare a brewing water based on the water recipe, wherein the water preparation unit is adapted to mineralize the brewing water according to the set mineral concentration of the water recipe; preparing brewing water based on the water recipe; and brewing the coffee-based beverage with the brewing water prepared according to the water recipe.

Systems and methods for treating wastewater with an oil-specific viscosifier composition and separating viscosified oil, undissolved solids and/or particulates, and/or other waste materials in such wastewater are provided. The methods further include: providing wastewater that includes oil; mixing the wastewater with an oil-specific viscosifier composition to form a viscosified oil; and separating at least a portion of the viscosified oil from the wastewater to provide treated water.

Systems and methods for treating wastewater with an oil-specific viscosifier composition and separating viscosified oil, undissolved solids and/or particulates, and/or other waste materials in such wastewater are provided. The methods further include: providing wastewater that includes oil; mixing the wastewater with an oil-specific viscosifier composition to form a viscosified oil; and separating at least a portion of the viscosified oil from the wastewater to provide treated water.