US 2014/0174942 A1 · Electrochemical System and Method for On-Site Generation of Oxidants at High Current Density

Abstract

An electrochemical system and method are disclosed for On Site Generation (OSG) of oxidants, such as free available chlorine, mixed oxidants and persulfate. Operation at high current density, using at least a diamond anode, provides for higher current efficiency, extended lifetime operation, and improved cost efficiency. High current density operation, in either a single pass or recycle mode, provides for rapid generation of oxidants, with high current efficiency, which potentially allows for more compact systems. Beneficially, operation in reverse polarity for a short cleaning cycle manages scaling, provides for improved efficiency and electrode lifetime and allows for use of impure feedstocks without requiring water softeners. Systems have application for generation of chlorine or other oxidants, including mixed oxidants providing high disinfection rate per unit of oxidant, e.g. for water treatment to remove microorganisms or for degradation of organics in industrial waste water.

Claims52

Dependent claims

A system for On-Site Generation (OSG) of an oxidant solution for chemical water treatment and disinfection comprising:

an electrochemical cell comprising an anode and a cathode defining an active area of the cell, at least the anode being a conductive diamond anode;
an input port and flow control means for injecting an aqueous electrolyte feedstock between the electrodes, said electrolyte feedstock consisting essentially of a salt solution having a concentration in the range greater than 0.5 Molar to 3 Molar, said salt being selected for electrochemical generation of an oxidant comprising one or more of hypochlorite, other free and available chlorine (FAC), hydrogen peroxide, ozone, mixed oxidant and peroxydisulfate;
current means for supplying current for electrolyzing the aqueous feedstock electrolyte at a current density in the range from 150 mA/cm2 to 1000 mA/cm2 to produce an oxidant solution containing said oxidant;
and
an output port for supplying the oxidant solution from the electrochemical cell.

2 more elements

Dependencies are inferred from the claim text.

Electrochemical System and Method for On-Site Generation of Oxidants at High Current Density

Life of this patent

Electrochemical System and Method for On-Site Generation of Oxidants at High Current Density

Life of this patent

Abstract

Claims52