Process, apparatus and article for treating an aqueous solution containing biological contaminants. The process includes contacting an aqueous solution containing a biological contaminant with an aggregate composition comprising an insoluble rare earth-containing compound to form a solution depleted of active biological contaminants. The aggregate includes more than 10.01% by weight of the insoluble rare earth-containing compound. The insoluble rare earth-containing compound can include one or more of cerium, lanthanum, or praseodymium. A suitable insoluble cerium-containing compound can be derived from a cerium carbonate, a cerium oxalate or a cerium salt. The composition can consist essentially of cerium oxides, and optionally, a binder and/or flow aid. The aggregate includes no more than two elements selected from the group consisting of yttrium, scandium, and europium when the aggregate is to be sintered. Although intended for a variety of fluid treatment applications, such applications specifically include removing or deactivating biological contaminants in water.

Apparatus and process for treating an aqueous solution containing biological contaminants

A method uses anionic and cationic polymers added in, any order or simultaneously, to aqueous media for the removal of substances. The sequential addition of the two biopolymers, anionic xanthan, followed by cationic chitosan, causes the rapid formation of very large and cohesive fibrillar aggregates that may exhibit high solids to liquid ratios and that quickly settle out from the aqueous media. The aqueous media can be easily separated from the large fibrillar aggregates by settling under gravity or by filtration through a porous containment device, such as a synthetic or non-synthetic woven or non-woven fabric including a geotextile fabric or a solid containment device containing a solid mesh screen.

Use of a dual polymer system for enhanced water recovery and improved separation of suspended solids and other substances from an aqueous media

The present invention is directed to the removal of one or more selected target materials from various streams using a rare earth metal-containing fixing agent.

Target material removal using rare earth metals

Arsenic is removed from water and other aqueous feeds by (1) treating the feed with a compound containing cerium in the +4 oxidation state, preferably cerium dioxide, to oxidize arsenic in the +3 oxidation state to arsenic in the +5 oxidation state and (2) removing the arsenic in the +5 oxidation state from the aqueous phase, normally by contacting the treated feed with alumina or other precipitating agent containing cations in the +3 oxidation state.

Process for removing arsenic from aqueous streams

An aggregate composition and process for making the aggregate composition. The aggregate composition includes an insoluble rare earth-containing compound and a polymer binder. The insoluble rare earth-containing compound can include one or more of cerium, lanthanum, or praseodymium. A suitable insoluble cerium-containing compound can be derived from cerium carbonate or a cerium salt. In a specific embodiment, the aggregate composition consists essentially of one or more cerium oxides, the polymer binder and optionally a flow aid. A process for making the composition includes mixing the insoluble rare earth-containing compound with a polymer binder to form a mixture, and subjecting the mixture to mechanical, chemical and/or thermal treatment to adhere the rare earth compound to the polymer binder. The aggregate composition can be used in a variety of fluid treatment applications to remove one or more chemical and biological contaminants in a fluid.

Composition and process for making the composition

The invention is a new composition and process for lanthanum oxide concentrate that is used to significantly reduce arsenic and/or selenium concentration levels in aqueous solutions. The lanthanum oxide concentrate is a mixture of lanthanum oxide and one or more oxides from the following group: neodymium oxide, cerium oxide, parseodymiun oxide, strontium oxide, calcium oxide and sodium oxide. The process of manufacture comprises the steps of sintering the lanthanum oxide concentrate, then washing the resultant media. The process of use is the contact of the lanthanum oxide concentrate with an aqueous solution containing arsenic and/or selenium whereby the lanthanum oxide concentrate removes at least a portion of the arsenic and/or selenium from the aqueous solution.

John F. Harck

Papers

Composition and process for removing arsenic and selenium from aqueous solution