The present invention provides compositions and methods of reducing cyanuric acid levels in recreational water systems.

Method and plant for treating water implementing a contact vessel (21) for putting water into contact with a granular adsorbent material and a clarification, granular adsorbent material is constituted by agglomerates of active carbon particles, said agglomerates having an average size of 200 μm to 600 μm and a specific surface area of 800 to 1000 m.sup.2/g, a screen (9) being provided in the upper part of the contact vessel (21) comprising a layer of porous material having a thickness of 1 to 5 mm and a cut-off threshold of 100 μm to 200 μm, said contact vessel (21) having a hopper-shaped lower part (21a), purging means (21b) and stirring means (22) to stir the content of the upper part of this contact vessel (21) without stirring the content of the lower hopper-shaped part.

The present disclosure provides a method for relieving a corrosive environment of a boiling water reactor, the method including a step of injecting hydrogen and a noble metal compound into water to be replenished into the reactor pressure vessel during a period of a generating operation of a boiling water nuclear power plant including the reactor pressure vessel. In the method, the hydrogen is injected into water to be supplied into the reactor pressure vessel, and the noble metal compound is injected into water in a line of the boiling water nuclear power plant in which a concentration of oxygen or hydrogen peroxide is stoichiometrically higher than the concentration of hydrogen at which hydrogen undergoes a chemical reaction to turn to water. Thus, when a noble metal is injected into a boiling water reactor, the noble metal can be restrained from adhering onto a pipe for an injection and other pipes, and thereby can increase the amount of the noble metal to be injected into a cooling water in a reactor pressure vessel.

A ballast water treatment operating apparatus includes a ballast water treatment unit for performing a certain treatment of ballast water flowing in from the outside for a ballast operation or performing a certain treatment of ballast water discharged into the outside for a de-ballast operation; a positional information receiving unit for receiving positional information; a control unit for confirming a ship's position by using positional information received from the positional information receiving unit and then determining whether to operate the ballast water treatment unit during a ballast operation or during a de-ballast operation, thereby being capable of preventing an unnecessary energy consumption.

The present invention relates to a bio-electrochemical system (BES) and a method of in-situ production and removal of H.sub.2O.sub.2 using such a bio-electrochemical system (BES). Further, the invention relates to a method for in-situ control of H .sub.2O.sub.2 content in an aqueous system of advanced oxidation processes (AOPs) involving in-situ generation of hydroxyl radical (OH) by using such a bio-electrochemical system (BES) and to a method for treatment of wastewater and water disinfection. The bio-electrochemical system (BES) according to the invention comprises:—an aqueous cathode compartment comprising a first cathode and a second cathode,—an aqueous anode compartment comprising an anode at least partly covered in biofilm, wherein the first cathode is connected to a first circuit and the second cathode is connected to a second circuit, wherein the first and the second circuit are connected to the system by an external switch.

Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.

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.

Method and system for treating wastewater includes treating sludge with ozone in a plug-flow type reactor to cause lysis of biosolids in the sludge. The ozonated sludge may be provided to an anaerobic or anoxic section of the wastewater treatment system to aid the denitrification processes occurring in the anaerobic or anoxic section of the wastewater treatment system or to other sections of the wastewater treatment system such as a fermenter, an aerobic digester, or an anaerobic digester.

Methods and systems for treating oil sands tailings streams at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises providing a tailings stream including 10-55% solids by total weight, increasing the pH of the tailings stream by combining the tailings stream with lime to produce a lime-tailings mixture having a pH of at least 11.0, and dewatering the lime-tailings mixture to produce a first stream having 10% or less solids by total weight and a second stream having 50% or more solids by total weight. The first stream can correspond to a release water stream, and the second stream can correspond to a cake. The lime slurry can include about 10% lime by total weight, and can comprise lime hydrate, quicklime, or a combination thereof. Dewatering the lime-tailings mixture can include routing the lime-tailings mixture to a centrifuge unit and/or a pressure or vacuum filtration unit.

A liquid purification system includes a raw liquid supply line with a sorbent dispenser connected to an inlet of a filtration cartridge with a precoated layer of sorbent formed and removable by flushing and a purified liquid line connected to a purified liquid output of the filtration cartridge. The system is configured to decant spent sorbent and return most of the flushing liquid to the raw liquid supply line. A flushing liquid and sorbent separation device is connected to a flushing liquid outlet of the filtration cartridge, and a clarified flushing liquid outlet of the flushing liquid and sorbent separation device is connected to the raw liquid supply line. The filtration cartridge is made as a hollow-fiber cartridge.