The methods disclosed generally relate to treatment of process water using chlorine dioxide. Specifically, reactants may be fed asynchronously into a diluent line or a tank where the reactants may mix and react to form chlorine dioxide. The chlorine dioxide levels may fluctuate in the diluent line or the tank thereby inhibiting or reducing the growth of microbes.

Systems and methods for producing chlorine dioxide in a two stage system and single stage system that provides high chlorate to chlorine dioxide efficiency with a compact design and low sulfuric acid requirements.

A method of sanitising a body of water including the steps of adding sodium chlorite and/or sodium chlorate to the body of water and converting the sodium chlorite and/or sodium chlorate to chlorine dioxide in an electrolysis cell which is in fluid communication with a water circulation system of the body of water.

A method for boosting the efficiency of chlorine dioxide production in a chemical facility. A chloride donor is introduced into a feed of sulfuric acid or a reducing agent, both of which are injected into the recirculation lines, or other areas, of a chlorine dioxide producing facility. The chloride donor provides the intermediate chemical species necessary for the efficient generation of chlorine dioxide at high acidities and/or the high local acidity in the wake zone of the acid injection location, thereby enabling greater efficiency in the reduction of chlorine dioxide from sodium chlorate.

This invention relates to aqueous solutions that contain chlorine dioxide, particularly ultrapure aqueous solutions of chlorine dioxide that can be used, for example, in the field of human and veterinary medicine to disinfect surfaces, devices and instruments, as well as a process for producing such aqueous solutions of chlorine dioxide. In particular, this invention is a process for producing an aqueous solution of chlorine dioxide in which a previously produced aqueous solution of chlorine dioxide is treated so that an ultrapure aqueous solution of chlorine dioxide is obtained. The invented process can be applied to all previously produced aqueous solutions of chlorine dioxide, regardless of the process used to produce these. The invented process can be used in particular to produce ultrapure aqueous solutions of chlorine dioxide much more easily and inexpensively from previously produced aqueous solutions of chlorine dioxide. Surprisingly, it was discovered that the aqueous solutions of chlorine dioxide produced using the invented process show a high level of purity and a surprisingly high level of stability.

Preparation of an aqueous chlorine dioxide solution that reaches a first chlorine dioxide concentration during a first time period, and reaches a terminal concentration thereafter. A dilute solution of aqueous sodium chlorite or chlorate with predetermined concentration is produced, which yields the terminal chlorine dioxide concentration once an acid activator is added. The dilute solution is transferred through a conduit into a sanitization zone. The acid activator is injected into the conduit at a rate and concentration selected to reach the first chlorine dioxide concentration at the end of the first time period, with a flow rate such that the activated dilute solution of aqueous sodium chlorite has passed through the conduit prior to reaching the first chlorine dioxide concentration, which thereby limits exposure of the conduit to levels less than the first chlorine dioxide concentration.

A gaseous species can be separated from an aqueous donor mixture and absorbed in an aqueous recipient mixture using a membrane separation apparatus while maintaining a large temperature difference (e.g. greater than 30° C.) between the two aqueous mixtures. A composite membrane is employed which comprises a non-porous membrane adjacent a porous membrane. The non-porous membrane is permeable to the gaseous species. The porous membrane has a porosity greater than 50% and is hydrophobic. In one embodiment, the composite membrane is oriented such that the porous membrane faces the aqueous recipient mixture and is impermeable thereto at the recipient mixture pressure. The invention is particularly suitable for separating chlorine dioxide from chlorine dioxide reaction liquor and absorbing in chilled water.

The present disclosure generally relates to methods of treating process water using a reactor for generating chlorine dioxide onsite. The onsite generation system may include double ensured precursor feeding, effective reactor, automated control/alarm, and effective product delivery. The reactor may include a mixing device, a first feed line connected to the mixing device, and a second feed line connected to the mixing device. The reactor may include a proximal portion in fluid communication with the mixing device and a distal portion in fluid communication with a motive water line. The mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line may be positioned within the motive water line.

A method of producing chlorine dioxide is disclosed. The method may include feeding a reaction mixture into a separator. The reaction mixture may follow a helical path through the separator and produce gaseous chlorine dioxide within the separator. Gaseous chlorine dioxide may be withdrawn from the separator and used to disinfect process water.

A method of producing chlorine dioxide is disclosed. The method may include feeding a reaction mixture into a separator. The reaction mixture may follow a helical path through the separator and produce gaseous chlorine dioxide within the separator. Gaseous chlorine dioxide may be withdrawn from the separator and used to disinfect process water.