2890 results about "Chlorine dioxide" patented technology

On-Line and Off-Line methods of simultaneously cleaning and disinfecting an industrial water system are described and claimed. The methods involve the addition to the water of the industrial water system of a Compound selected from the group consisting of the alkali salts of chlorite and chlorate and mixtures thereof; and an acid, followed by allowing the water in the industrial water system to circulate for several hours. The reaction of the alkali salts of chlorite and chlorate and acid produces chlorine dioxide in-situ in the water of the industrial water system. The chlorine dioxide kills microorganisms and the acid acts to remove deposits upon the water-contact surfaces of the equipment. An alternative method involves the use of a chelating agent and a biocide. Other possible cleaning and disinfection reagents may be added as needed including corrosion inhibitors, chelating agents, biocides, surfactants and reducing agents. These cleaning and disinfecting methods work in a variety of industrial water systems including cooling water and boiler water systems.

A process for bleaching mechanical wood pulp is provided comprising subjecting the wood pulp to at least one bleaching stage with one or more bleaching agents in the presence of one or more optical brightening agent, wherein the bleaching agents are selected from the group consisting of oxidative bleaching agents other than chlorine based bleaching agents such as chlorine dioxide, elemental chlorine or a combination thereof, reductive bleaching agents or any combination of two or more thereof.

An aqueous solution of metal chlorate, mineral acid and a reducing agent are continuously or intermittently sprayed, in a pattern to achieve intimate mixing, into a spherical chamber creating an aqueous foam reaction mixture generating chlorine dioxide which is removed in a direction 90 degrees to the axis of the spray nozzles. A baffle plate may be used to reduce the open cross sectional area of the exit port to increase reaction efficiency. The reactants are a mineral acid and an alkali metal chlorate or chloric acid and a reducing agent such as hydrogen peroxide. The mineral acid is either diluted or concentrated sulfuric acid, hydrochloric acid, acetic acid, nitric acid or a blend thereof. The ratio of acid is greater than one and less than 3 kg acid per kg of ClO2 formed. The chlorine dioxide may be removed with a stripper column.

The invention described relates to gelled chlorine dioxide compositions comprising water, an acid, a water-soluble chlorite salt and a gelling agent in two parts A and B, wherein the gelling agent is xanthan gum or a mixture of xanthan gum and an acid stable gelling agents. Compositions according to the invention are storage stable for at least 6 months, preferably at least about year.

Various devices allow for sanitization or disinfection by exhausting a dry fog biocide agent into an ambient environment. A nebulizer, for instance a vibrator that oscillates or vibrates at ultrasonic frequencies, nebulizes a biocide agent, for instance chlorine dioxide, peracetic acid, hydrogen peroxide, to create the dry fog. Such devices may withdraw the dry fog or biocide agent from the ambient environment after some period of time. Operational parameters of the devices may be tracked or monitored. Each device may implement tracking or monitoring. Additionally or alternatively, a separate tracking or monitoring system may track or monitor the operational parameters of one or more devices. Tracking or monitoring may include exception reporting, as well as other reporting.

The invention relates to a chemical industry park's wastewater bio-treatment apparatus and a method thereof. The apparatus contains an equalizing tank, a primary settling tank, an improved ABR apparatus, a first-stage anoxic pool, a first-stage powdered active carbon aeration tank, a secondary-stage anoxic pool, a secondary-stage aeration tank, a secondary sedimentation tank, an ozone oxidation pool, a coagulation pool, a rotary disk filter, a chlorine dioxide disinfection pool and a sludge thickener. An UASB reactor is adopted in a first-grid reaction zone of the improved ABR apparatus so as to increase the first-grid sludge concentration and raise shock load resistance of an anaerobic reactor and biodegradability of wastewater. According to the two-stage A / O treatment technology, powdered active carbon is added into the first-stage aeration tank to enrich microorganisms and simultaneously absorb part of poisonous and harmful substances, thus mitigating or eliminating the inhibition effect of the poisonous and harmful substances on microorganisms in subsequent units; and the second-stage A / O system operates to further remove nitrogen and organic matters. An effluent in the secondary sedimentation tank undergoes depth treatments such as ozone oxidation, coagulation-filtration, disinfection and the like so as to further remove organic matters and suspended matters. The effluent is reused according to requirements.