Method and apparatus for controlling microorganisms
US5424032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 1993 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Dec 13, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2301/046
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Water in a process water system, such as a cooling tower or pulp and paper processing plant, is treated to destroy biological microorganisms by diverting the portion of the water flowing through the system to a side stream. In the side stream, chemicals are added such as halide ions or sodium chlorite. The water is then passed through an electrolysis unit or a UV radiation unit to oxidize the precursor to form an active oxidant. Advantageously, the pH of the side stream can be lowered to significantly improve the oxidization of the halide ions. When a very small portion of the flow rate is passing through the side stream, the acid added does not significantly alter the pH of the entire system. In a preferred embodiment, the acid added is phosphonic acid which acts as an antiscalant. Also included in the present invention is a method to inject oxidant precursors into a process water system through an oxidant generation station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.