A resin is provided for selectively binding to perchloride and related anions (e.g., TcO.sub.4.sup.−, ReO.sub.4.sup.− and I.sup.−) in aqueous solution. The resin may take the form of microparticles or beads. The beads are prepared by cross-linking macromolecules such as hyperbranched PEI, and quaternizing the amines with hydrocarbon substituents.

A method for producing ultrapure water includes supplying raw water (industrial water, tap water, well water, or used ultrapure water discharged from semiconductor plants) to a pretreatment system for treating the raw water to produce water, supplying the water to a primary water purification system having a reverse osmosis membrane separation unit to produce a primarily purified water, and supplying the primarily purified water to a secondary purification system to produce ultrapure water.

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 and a free radical removal system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The free radical removal system can comprise use of a reducing agent. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized to regulate addition of the precursor compound, the intensity of the actinic radiation, and addition of the reducing agent to the water.

Provided are a method and an apparatus for producing pure water in which water that has been subjected to an ultraviolet oxidation treatment performed with an ultraviolet oxidation device is brought into contact with a platinum-group metal catalyst, the method and apparatus eliminating the likelihood of the catalyst being degraded and enabling decomposition of hydrogen peroxide to be performed for a prolonged period of time in a consistent manner. Water-to-be-treated is subjected to an ultraviolet oxidation treatment performed with an ultraviolet oxidation device and subsequently subjected to a hydrogen peroxide removal treatment performed with a hydrogen peroxide removal device including a platinum-group metal catalyst. The TOC concentration in water fed to the ultraviolet oxidation device is 5 ppb or less. An anion exchange resin tower is installed in a stage following the ultraviolet oxidation device.

Fine particles that are contained in ultrapure water supplied to a point of use is further reduced.

Ultrapure water production system has ultrapure water supply line that is connected to point of uses, wherein ultrapure water flows through ultrapure water supply line; and first ion exchange apparatus, membrane filtration apparatus and second ion exchange apparatus that are arranged in series on ultrapure water supply line. Membrane filtration apparatus is arranged between first ion exchange apparatus and second ion exchange apparatus. At least a part of the ultrapure water that flows out from membrane filtration apparatus is treated by second ion exchange apparatus before the at least a part of the ultrapure water is supplied to point of uses.

Various examples related to electrokinetic dewatering (EKD) of suspensions such as, e.g., phosphatic clay suspensions are provided. In one example, a system for continuous EKD includes cake dewatering unit having a lower conveying belt extending across a dewatering chamber; an upper conveying belt extending across at least a portion of the dewatering chamber; and a sludge inlet configured to supply a sludge suspension on the first end of the lower conveying belt. The conveying belts can extend across the dewatering chamber at an angle. Rotation of the conveying belts draws the sludge suspension through an electric field where the sludge suspension is dewatered. The electric field can be established between an upper anode and a lower cathode. The upper and lower conveying belts can include the anode and cathode. A suspension thickening unit can provide a thickened sludge suspension the cake dewatering unit for enhanced dewatering.

A water quality management method for managing the concentration of impurity ions contained in the water to be analyzed includes connecting the ion adsorption device in which the ion adsorbent and the accumulated flow rate meter are provided to the blanch pipe, passing the water being analyzed from the blanch pipe to the ion adsorbent for a predetermined period of time to the ion adsorption device and adsorbing ions contained in the water being analyzed an ion adsorbent sample. In the ion adsorption device, an accumulated flow rate meter is provided on the downstream side of the flow direction of the water being analyzed of the ion adsorbent.

A method, system and composition is described for treating waste generated from manufacturing operations including at least one of Printed Circuit Boards Fabrication (PCB FAB), General Metal Finishing (GMF), semiconductors manufacturing, chemical milling, and Physical Vapour Deposition (PVD). The method, system and composition are used to create zero liquid discharge recycling.

A hand-holdable portable water purifying and dispensing unit is described comprising at least a housing, a purified water inlet, a further-purified water dispense outlet, a dispense operator, a reservoir, one or more water further-purification devices, and an internal water recirculation pump and pathway, said pathway including the reservoir and the one or more water further-purification devices. Optionally, the reservoir has a volume in the range 100 ml to 2000 ml, preferably in the range 200 ml and 1000 ml.

In a system for decomposing organic compounds in water for use in semiconductor manufacturing, a chemical reactor vessel having a fluid inlet and a fluid outlet, a persulfate anion addition system upstream of the reactor vessel, and a light emitting device contained within the reactor vessel. The light emitting device provides light capable of decomposing persulfate anions.