For the trade press
Warrendale - Monday, June 09, 2008
AWWA 2008
Chlorination as a Drinking Water Disinfectant: 100 Years and Counting
This year marks the 100th anniversary of one of the most significant public health advancements of the millennium: the introduction of drinking water chlorination on a large scale. In 1908, the Jersey City, New Jersey Water Works became the first U.S. water system to chlorinate on a permanent basis. The practice spread to other areas of the country, virtually eliminating waterborne diseases such as cholera, typhoid, dysentery and hepatitis A. Sodium hypochlorite (chlorine bleach) in the parts-per-million level was added to water to eliminate the micro-organisms that caused the waterborne disease outbreaks. Hypochlorite, however, was not easy to handle, and application at low feed rates was difficult and often unreliable. This problem was solved in 1913 by the Wallace & Tiernan Company with the invention of a chlorine gas feeder they aptly named the chlorinator.
Using special materials, a unique control valve and an inverted, siphon-type flow meter, the chlorinator proved to be a reliable way to feed pure chlorine gas, and by 1920, the company had completed over 2,000 successful installations. The ability to feed relatively inexpensive and stable chlorine gas, compared to hypochlorite, led to the rapid, safe disinfection of water supplies on a global scale. Wallace & Tiernan went on to develop a variety of disinfection products for various applications in the municipal, industrial and commercial markets.
Now offered as part of the Chemical Feed Group at Siemens Water Technologies, Wallace & Tiernan products include a wide range of chemical feed and disinfection equipment for virtually every water or wastewater treatment application. These include chlorine gas dispensing and vaporizing equipment, analytical and control equipment for disinfection systems, liquid metering and dosing pumps, dry chemical feeders, pre-engineered systems for lime slaking, polymer-feed (liquid and dry) systems, OSEC on-site hypochlorite generators, chlorine-dioxide generators, ultraviolet (UV) disinfection systems, fluoridation systems, sulphur dioxide and ammonia gas feeders, chlorine gas detectors, and flow meters.
The products are manufactured in the United States, United Kingdom and Germany, with business and distribution centers in Canada, Australia and China as well as manufacturer’s agents and representatives around the world.
OSEC is a trademark of Siemens and/or its affiliates in some countries.
The Siemens Industry Sector (Erlangen, Germany) is the world's leading supplier of production, transportation and building systems. Integrated hardware and software technologies combined with comprehensive industry-specific solutions enable Siemens to enhance the productivity and efficiency of its customers in industry and infrastructure. The Sector comprises six Divisions: Building Technologies, Industry Automation, Industry Solutions, Mobility, Drive Technologies and Osram. In fiscal 2007 (ended September 30), Siemens Industry generated sales of approximately EUR40 billion (pro forma, unconsolidated) with around 209,000 employees worldwide. http://www.siemens.com/industry
With the business activities of Siemens VAI Metal Technologies, (Linz, Austria), Siemens Water Technologies (Warrendale, Pa., U.S.A.), and Industry Technologies, (Erlangen, Germany), the Siemens Industry Solutions Division (Erlangen, Germany) is one of the world's leading solution and service providers for industrial and infrastructure facilities. Using its own products, systems and process technologies, Industry Solutions develops and builds plants for end customers, commissions them and provides support during their entire life cycle.
Further information and downloads at: http://www.siemens.com/water