compared to conventional chlorination methods which apply chlorine at water treatment plant, booster chlorination has almost solved the problems of high dosages of chlorine residuals near water sources and lack of chlorine residuals in the remote points of a water distribution system (wds). however, control of trihalomethane (thm) formation as a potentially carcinogenic disinfection by-product ...

BACKGROUND: The practice of using disinfectants to safeguard against the acute effects of waterborne disease are well established and regulated in the United States. New regulations designed to minimize the risks associated with chronic exposure to disinfection by-products (DBPs), however, are changing the current regulatory framework. Changes in disinfection practices meant to comply with thes...

Concerns have been raised regarding disinfection by-products (DBPs) formed as a result of the reaction of halogen based disinfectants with DBP precursors. In order to appreciate the chemical and biological tradeoffs, it is imperative to understand the formation trends of DBPs and their spread in the distribution network. However, the water at a point in a complex distribution system is a mixtur...

infection by m. tuberculosis can be demonstrated by tuberculin testing. on sequential ppd some person show a marked increase in the size of their skin reactions which may not be due to recent or past tuberculous infection. this phenomenon (booster effect) can occur as soon as a week after the initial test and persist for as long as a year. methods and materials: the purpose of this research is ...

Mussel control in cooling water systems is generally achieved by means of chlorination. Chlorine is applied continuously or intermittently, depending on cost and discharge criteria. In this paper, we examined whether mussels will be able to survive intermittent chlorination because of their ability to close their valves during periods of chlorination. Experiments were carried out using three co...

This study investigated the effects of preozonation on disinfection by-products (DBPs) formation during chlorination and chloramination of the water collected from Tai Lake. Results showed that the high ozone dose (0.6-1.0 mg O₃/mg DOC) pretreatment reduced the yields of trihaloacetic acids (reduced 62-63% in chlorination), dihaloacetonitriles (reduced 53-55% and 14-26% in chlorination and chlo...

OBJECTIVE To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. METHODS Pilot tests of this sequential chlorination were carried out in a drinking water plant. RESULTS The sequential chlorination disinfection process had the same or better efficiency on microbe (including virus) inactivation compared with the...