A method and system of providing ultrapure water for semiconductor fabrication operations is provided. The water is treated by utilizing a free radical scavenging system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized to regulate a continuously variable intensity of the actinic radiation.

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 for enhancing biochemical water treatment by a powder carrier includes: (i) screening the powder carrier by removing impurities to obtain a screened powder carrier; (ii) dissolving the screened powder carrier by stirring to prepare a slurry, enabling the screened powder carrier to completely absorb moisture to obtain a soaked powder carrier slurry; (iii) adjusting the pH value and adding the soaked powder carrier slurry into a bioreactor or a biological reaction structure; (iv) distributing the soaked powder carrier slurry uniformly through a hydraulic agitation; (v) loading a microorganism on the inner pore and wrapping on the surface of the soaked powder carrier slurry to obtain powder-loaded biological floccules; (vi) settling the powder-loaded biological floccules in a sedimentation zone and separating the powder carrier from the microorganism for reuse.

Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.

Methods for removing polymers from treatment fluids for use in subterranean formations are provided. In one or more embodiments, the methods include providing a treatment fluid comprising an aqueous base fluid and a polymer comprising polyvinylpyrrolidone or a derivative thereof; and adding a precipitant to the treatment fluid to form a precipitate with at least a portion of the polymer.

The present inventors have developed systems and processes for reducing the overall carbon consumption needed for the generation of low COD treated water. In certain aspects, the systems and processes described herein include an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or a combination thereof for oxidation) between a first activated carbon stage and a second activated carbon stage to reduce a total carbon consumption within the associated system or process.

An atmospheric water generation system comprises water vapor consolidation systems configured to increase the relative humidity of a controlled air stream prior to condensing water from the controlled air stream. The water vapor consolidation system comprises a fluid-desiccant flow system configured to decrease the temperature of the desiccant to encourage water vapor to be absorbed by the desiccant from an atmospheric air flow. The desiccant flow is then heated to encourage water vapor evaporation from the desiccant flow into a controlled air stream that circulates within the system. The humidity of the controlled air stream is thereby increased above the relative humidity of the atmospheric air to facilitate condensation of the water vapor into usable liquid water.

A capture unit for use with an antimicrobial application unit may include an upstream filter and a downstream filter. The upstream filter may be positioned to receive effluent from the application unit and to filter solid components from the effluent. The resultant upstream effluent filtrate may then be passed downstream to the downstream filter. The downstream filter may be used to filter an antimicrobial component from the upstream effluent filtrate and the resultant downstream effluent filtrate may be suitable for disposal as wastewater discharge. The antimicrobial is preferably a quaternary ammonium compound, is more preferably an alkylpyridinium chloride, and is most preferably cetylpyridinium chloride.

The present embodiments generally relate to the treatment of produced water comprising one or more water soluble polymers, wherein such treatment comprises: adding to the produced water at least one iron complex; and degrading at least a portion of the one or more water soluble polymers. This treatment may result in a reduction of the viscosity of said produced water and/or the degradation of the water soluble polymers which are contained therein.

Disclosed herein is a method for remediating sewage that contains persistent contaminants. The method comprises ozofractionating the sewage under conditions whereby a foam fractionate comprising persistent contaminants is produced and separated from an ozofractionated wastewater, quiescing the ozofractionated wastewater, whereby a residual ozone content of the ozofractionated wastewater is reduced, and contacting the quiesced ozofractionated wastewater with a microorganism population under conditions effective to biologically remediate the ozofractionated wastewater.