A water treatment system includes a water tank, a water filtration media, and an ozone gas source. A control system operates a service mode of the water treatment system during which an external water source is filtered by the filtration media. The control system also operates a regeneration mode of the water treatment system for regenerating the filtration media. The regeneration mode includes a first backwash mode to backwash the filtration media with the external water source. The regeneration mode includes a draw mode subsequent to the first backwash mode to draw ozone into the water tank and into contact with the filtration media. The regeneration mode includes a second backwash mode subsequent to the draw mode to expel ozone from the water tank and the filtration media prior to switching the system back into the service mode for filtration of the water source with the regenerated filtration media.

A wastewater treatment system includes a circulating fluidized bed evaporator defining a longitudinal axis vertical with respect to gravity. The evaporator has a wastewater inlet to provide wastewater to the circulating fluidized bed evaporator. A heat inlet is axially below the wastewater inlet to provide heat to the circulating fluidized bed evaporator for evaporating the wastewater. An outlet is axially above the wastewater inlet and the heat inlet.

Compositions and methods for treating waste water produced by copper mining operations are described herein. Slag from steel making operations and other industrial waste materials that include alkali metal and/or alkaline earth elements have been found to both raise pH of the waste water and also reduce arsenic content. Following such treatment the spent slag or industrial waste can be utilized as a source of valuable metals or incorporated into stabilized building materials.

The present invention provides for a system for removing arsenic from an arsenic contaminated aqueous solution, and its use thereof. The system comprises an anode comprising iron and a cathode comprising iron or an electricity conducting metal that is electropositive relative to iron in contact with the arsenic contaminated aqueous solution. The system is used by running an electric current through the water via the anode and cathode to cause the formation of iron (hydr)oxide from the iron of the anode which then forms an insoluble arsenic-iron (hydr)oxide complex which can be separated from the aqueous solution.

The present invention relates to a method of removing chromate ions from an ion-exchange effluent, the method comprising: (i) providing an ion-exchange effluent comprising chromate ions obtained from the regeneration of an ion-exchange material, (ii) admixing the ion-exchange effluent with a source of alkali metal dithionite to form a first precipitate, and (iii) removing the first precipitate

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.

A filter media for the filtration of potable water; specifically, for the removal of arsenic from potable water using iron-impregnated activated carbon enhanced with titanium oxide, such as the titanium oxide mixture used in the commercial product Metsorb®. The activated carbon is subjected to a wet impregnation process using an iron salt solution of approximately 6% of iron(III) chloride FeCl.sub.3 solution and 1.25% of NaOH solution.

Methods for removing one or more contaminants from an aqueous stream comprising: adding one or more hydraulic binders and one or more promoters to the aqueous stream, and separating the contaminants from the aqueous stream are provided. The methods may be used for removing contaminants that are arsenic-based, selenium-based, cadmium-based, zinc-based, mercury-based, iron-based, chromium-based and/or phosphate-based.

According to present disclosure, there is disclosed an algae growth and cultivation system that provides a cost-efficient means of producing algae biomass as feedstock for algae-based products, such as, biofuel manufacture, and desirably impacts alternative/renewable energy production, nutrient recovery from waste streams, and valued byproducts production. The system as discussed herein is an integrated systems approach to wastewater treatment, algal strains selection for byproducts production, and recycle of algal-oil extraction waste or additional algae harvested as feedstock for fertilizer production. Embodiments of a system as discussed herein present an economically viable algae production system and process that allows algae-derived products such as biofuels, fertilizer, etc. to compete with petroleum products in the marketplace.

In one embodiment, a treatment system for removing dissolved contaminants (e.g., arsenic) from a contaminated fluid (e.g., water) utilizes in-situ generation of adsorption filtration media or reactive components. Corrosion materials (e.g., iron oxide complexes) that serve as the adsorption filtration media or reactive components are generated by supplying a flow of contaminated fluid, and injecting air, into a generator vessel containing pieces of an oxidizable source (e.g., zero-valent iron spheres). The pieces of the oxidizable source are agitated to release particulates of corrosion materials from their surface into solution with the contaminated fluid. Simultaneous to the ongoing generation of corrosion materials, dissolved contaminants in the contaminated fluid are adsorbed on the corrosion materials. New particulate compounds generated by adsorption of the dissolved contaminants on the corrosion materials precipitate from the solution, and are filtered out, thereby removing the contaminants, and yielding treated fluid (e.g., potable water).