Envirex Inc.

Siemens Water Technologies Holding Corp.

Other

Evoqua Water Technologies Pte. Ltd.

Usfilter Corporation

Charles Stark Applegate

David W Dubey

Michael L Doyle

George W Smith

Peter J Petit

Paul R Erickson

William H Boyle

Marc E Roehl

Mark F Pamperin

Christopher K Waul

Richard E Wullschleger

Mark Franklin Pamperin

Christopher S Waul

Aeration discs used in water treatment and methods of using same are disclosed. According to one or more embodiments, an aeration disc may comprise projections and depressions located on at least one of its surfaces. The aeration discs may be incorporated into aeration devices and water treatment systems.

Aeration discs and methods for using same

A wastewater treatment method. The method includes establishing a setpoint value of oxidation-reduction potential of a mixed liquor, measuring a measured value of oxidation-reduction potential of the mixed liquor, comparing the measured value of oxidation-reduction potential and the setpoint value of oxidation-reduction potential, generating a control signal based at least in part on the step of comparing, controlling operation of an aeration device using the control signal, acquiring at least one value corresponding to the control signal and adjusting the setpoint value of oxidation-reduction potential using the at least one value. The value includes a frequency of operation of the aeration device.

Wastewater treatment control

A method and apparatus for conditioning a sensor to measure an oxidation reduction potential of an aqueous solution such that the time to obtain a reliable oxidation reduction potential measurement is substantially reduced. Such conditioning is often necessary when the sensor is moved from potentiometric equilibrium (e.g., the sensor is cleaned, the sensor is exposed to air, and the like). The method may comprise generating a current through a measurement electrode and a reference electrode of the sensor for a duration of time. A reliable oxidation reduction potential measurement can be made as the voltage across the measurement electrode and the reference electrode stabilizes after the duration of time. Depending on the aqueous solution, the stabilized value can be constant or variable.

Method and apparatus for conditioning a sensor for measuring oxidation reduction potential

Wastewater treatment controls that maintain the ORP of a mixed liquor at a relatively stable value during a wastewater treatment process such as an aerated-anoxic wastewater treatment process. The wastewater treatment control may compare a setpoint value of ORP and a measured value of ORP of the mixed liquor, generate a control signal based at least in part on the comparison, and control a biological nutrient removal control parameter using the control signal. Values corresponding to the control signal may be acquired and utilized to adjust the setpoint value of ORP to maintain stable operating conditions of the wastewater treatment process.

A dissolved gas flotation system for treatment of wastewater or contaminated water and having an improved flow pattern wherein the subnatant discharge outlet and the inlet distribution structures are located adjacent one another. Such a structural design takes advantage of the fluid flow patterns within the tank to maximize the effect of the air bubbles in separating solids from the fluid.

Dissolved gas floatation device

An antifouling electrochemical gas sensor is disclosed in which the sensor has a cell containing two spaced apart electrodes immersed in an electrolyte and a membrane over an opening in the end of the cell which is immersed in a medium containing varying concentrations of a gas to be sensed, typically oxygen. The electrodes are also connected to an external electrical circuit which indicates the current flow between the electrodes as a result of oxidation and reduction reactions at the electrodes caused by oxygen diffusing through the membrane into the cell. The sensor has a sensing mode during which it functions to indicate the amount of oxygen in the medium. The sensor also has a cleaning mode in which the current flow across the electrodes is in an opposite direction to cause a reaction at one of the electrodes producing a biocidal gas. The biocidal gas diffuses through the membrane from the interior of the cell to the exterior surface of the membrane to kill biological growths and organic deposits on the surface of the membrane and thereby clean the surface of the membrane.

Antifouling electrochemical gas sensor

A process for removing colloidal and soluble contaminants from impure water moving through a hollow, cylindrical microscreen under a positive head pressure, comprising dispersing insoluble, finely divided particulate matter into the impure water and rotating the microscreen at a rate that will form, during each rotation thereof, an intermixed layer of contaminants and particulate matter over substantially the entire inner surface of the microscreen through which the impure water is passing. The intermixed layer forms a filter substantially impermeable to contaminants and particulate matter of a size that could pass through the microscreen pores, but it is not impermeable to water. Preferably, the finely divided particulate matter can be a sorbent material, e.g. powdered activated carbon, so that contaminants are both filtered and sorbed from the water.

Growing community of inventors

Brookfield, WI, United States of America

Charles Stark Applegate