The present invention relates to the use of particulate mineral material comprising barite for scavenging heavy metal anions from a liquid medium, wherein the heavy metal anions form water-insoluble barium salts with barium cations of the barite, and wherein the particulate mineral material has a specific surface area of from 0.1 m.sup.2/g to 100 m.sup.2/g, measured using nitrogen sorption and the BET method.

A water purification chamber is provided. In one embodiment, a system comprises a purification chamber comprising a selective adsorbent activated carbon fiber fabric including one or more selective functional groups that bind arsenic.

A reagent system for treating heavy metal-contaminated materials is provided and includes an oxidizer, a soluble phosphate, and an alkaline hydroxide source, such as a caustic soda or lime. A method of treating mine waste bearing one or more heavy metals is also provided and includes the step of admixing a reagent system with heavy metal-containing material to preferentially reduce the leachability of heavy metals and form precipitates and complexes of low metal solubility that remain stable within the host solid matrix for long durations in acidic and abrasive conditions.

A process for the treatment of thick fine tailings that include constituents of concern (CoCs) and suspended solids is provided. The process includes subjecting the thick fine tailings to treatments including chemical immobilization of the CoCs, polymer flocculation of the suspended solids, and dewatering. The chemical immobilization can include the addition of compounds enabling the insolubilization of the CoCs. Subjecting the thick fine tailings to chemical immobilization and polymer flocculation can facilitate production of a reclamation-ready material, which can enable disposing of the material as part of a permanent aquatic storage structure (PASS).

Copper based nanoparticle composite compositions, methods, and systems for purification and sterilization of contaminated water are provided.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

The invention relates to a method for the precipitation of arsenic and heavy metals from acidic, in particular sulphuric acid, process water (12), containing both arsenic and heavy metals, comprising a precipitation method phase (II) with a sulphide precipitation stage (C) in which arsenic and at least one primary heavy metal are precipitated together, wherein a sulphide precipitating agent (16) is added to the process water (12) such that arsenic is precipitated as arsenic sulphide and the at least one primary heavy metal is precipitated as metal sulphide. The sulphide precipitation stage (C) comprises a first sulphide precipitation step (C.1) in which a sulphide precipitating agent is added to the process water (12) in a first sulphide precipitation reactor (14), whereby an intermediate fluid (22) is generated still containing arsenic or still containing arsenic and the primary heavy metal. The intermediate fluid (22) is transferred into a second sulphide precipitation reactor (30) after the first sulphide precipitation step (C.1). The sulphide precipitation stage (C) comprises a second sulphide precipitation step (C.2) in which a sulphide precipitating agent is added to the intermediate fluid (22) in the second precipitation reactor, whereby a residual fluid (32) is generated which is substantially free from arsenic.

Solid-supported trithiol compounds are prepared. The solid-supported trithiol compounds have formula (I): ##STR00001##
in which R is a linker moiety, X is a solid support, and n≧1. The compounds of formula (I) may be incorporated into methods for removing heavy metals from solutions and into batch systems or filtration apparatus that remove heavy metals from solutions.

The present invention relates in part to a filter comprising a tubular housing having a proximal end, a distal end and a housing lumen therethrough; a tubular membrane having a proximal end, a distal end and a membrane lumen therethrough, wherein the tubular membrane is positioned within the housing lumen; a contaminated fluid sample inlet fluidly connected to the proximal end of the membrane, and a contaminated fluid sample outlet fluidly connected to the distal end of the membrane, thereby creating a sample flow-path from the sample inlet through the membrane lumen to the sample outlet; and a purification material inlet fluidly connected to a distal region of the housing lumen, and a purification material outlet fluidly connected to a proximal region of the housing lumen, thereby creating a purification material flow-path from the purification material inlet through the housing lumen to the purification material outlet; wherein the direction of the sample flow-path is in the opposite direction of the purification material flow-path. The invention also relates a method of purifying a contaminated fluid using said filter.

The present invention relates to a medium material for eliminating arsenic pollution from groundwater, which is a granular material having an average particle diameter of 1 to 3 cm, prepared from manganese ore, meerschaum, straws, animal excrements, active sludge and active bacterium agent in a mass ratio of 1:0.2˜0.5:0.5˜1:0.2˜0.4:0.2˜0.4:0.0005˜0.002 via mixing, composting, carbonizing and crushing. The prevent invention also discloses a process for producing the above-mentioned medium material. The medium material of the present invention can eliminate multivalent arsenic from groundwater, has a long service life, and does not cause secondary pollution to groundwater.