US 7,678,238 B2 · Method and apparatus for underwater decomposition of organic content of electrically conductive aqueous waste solutions

Abstract

The object of the present invention is a method and an apparatus for underwater decomposition of organic content of aqueous waste solutions, involving the measurement and, if necessary, adjustment of the pH and electric conductivity of the solution, maintaining optimum pH and/or electric conductivity during the process, and further involving the partial or total decomposition of organic materials contained by the solution. The apparatus comprises a feed tank, at least one decomposition loop, and a storage tank. The method according to the invention is characterized by submerging electrodes in the solution, producing and maintaining an electric arc between the electrodes and the electrically conductive the solution, where the arc is produced by an electric current of at least 0.5 A/cm2 current density at a voltage of at least 70 V and by a symmetrical alternating current having preferably a frequency of at least 10 Hz; and by decomposing the organic content of the solution into water, carbon dioxide, and nitrogen.

Claims20

Dependent claims

A method for underwater decomposition of organic content of aqueous waste solutions, involving the measurement and, if necessary, the adjustment by means of a pretreating solution of the pH and electric conductivity of the solution, maintaining optimum pH and/or electric conductivity during the process, and further involving the total or partial decomposition of organic content of the solution, comprising:

submerging electrodes including a working electrode and an auxiliary electrode into the solution, and producing and maintaining an electric arc between the electrodes and the electrically conductive solution by applying electric current of at least 0.5 A/cm2 current density at a voltage of at least 70 V, and applying symmetrical alternating current having a frequency of at least 10 Hz;
and
decomposing the organic content of the solution into water, carbon dioxide, and nitrogen,
wherein the total surface area of the working electrode is smaller than the total surface area of the auxiliary electrode, and plasma is generated close to the working electrode where the current density is higher.

1 more element

An apparatus for underwater decomposition of organic content of electrically conductive aqueous waste solutions, comprising a feed tank, at least one decomposition loop, and a storage tank, the feed tank and the storage tank being connected to said decomposition loop through a feed pump, and the decomposition loop being connected with a pretreating solution tank through an adjusting unit and a feed pump;

and the decomposition loop comprising electrodes being submerged into the waste solution, wherein said electrodes are connected to a current source, and comprising a batch-mode decomposition loop comprising a post-decomposing batch reactor, a buffer tank, and a circulation pump, with a splash condenser connected to the batch reactor, wherein said splash condenser condenses and at least partially recycles into said batch reactor vapors produced therein, and with electrodes being submerged into the waste solution in said batch reactor, wherein said electrodes are connected to a current source supplying electric current of at least 0.5 A/cm2 current density at a voltage of at least 70 V that is capable of producing and maintaining an electric arc between the electrodes and the waste solution, with said current source producing symmetrical alternating current having a frequency of at least 10 Hz.

Dependencies are inferred from the claim text.

Method and apparatus for underwater decomposition of organic content of electrically conductive aqueous waste solutions

Life of this patent

Method and apparatus for underwater decomposition of organic content of electrically conductive aqueous waste solutions

Life of this patent

Abstract

Claims20