The feasibility of on-site generated chlorine (OSG chlorine) as an alternative disinfectant to gas was evaluated in terms total organic carbon (TOC) removal, disinfection efficiency, biofilm control, by-products (DBPs) formation, decay rate, and volatility. Chlorine decreased the pH treated water by -0.1 per mg/L free available (FAC) while OSG increased + 0.06 mg/L. with more hypochlorite ion (...

Protecting civilian and military water supplies has received more attention since the United States began its war on terror in 2001. Both chlorine and bromine are used by branches of the U.S. military for disinfecting water supplies; however, limited data exists as to the effectiveness of these additives when used against viral biowarfare agents. The present study sought to evaluate the surviva...

Based on density functional theory (DFT) calculations we study the electrochemical chlorine evolution reaction on rutile (110) oxide surfaces. First we construct the Pourbaix surface diagram for IrO(2) and RuO(2), and from this we find the chlorine evolution reaction intermediates and identify the lowest overpotential at which all elementary reaction steps in the chlorine evolution reaction are...

We compared the survival of F-specific RNA coliphage MS2, feline calicivirus, and E. coli in normal tap water and in tap water treated to an initial concentration of 50 ppm free chlorine and held at 4 degrees C, 25 degrees C, or 37 degrees C for up to 28 days. Our aim was to determine which of these two organisms (coliphage or E. coli) was better at indicating norovirus survival under the condi...

The purpose of this study was to measure the chlorine and monochloramine inactivation kinetics of Nitrosomonas europaea at 21 degrees C in the presence and absence of particles. The inactivation kinetics rates were compared with those obtained with Escherichia coli O157:H7. The results show that, in pure water, the use of free chlorine produced 4 log10 of N. europaea inactivation at a CT value ...

ADEQUATE protection of swimming pool waters has been of paramount importance for many years to health officials who are charged with responsibility for the safety and health of the public. The use of the chlorine compounds or of chlorine gas has been written into practically every regulation concerned with the disinfection of drinking water. The limitations of chlorine for swimming pool water t...

The Umgeni Water Wiggins water treatment plant feeds the southern areas of Durban in South Africa and has a maximum treatment capacity of about 350 Ml/d. Two interconnected reservoirs at this facility hold treated water before it enters the distribution network. Because of the variable demand, the reservoir levels and residence times undergo considerable variation. This has a strong influence o...

A sequential injection (SI) method was developed for the spectrophotometric determination of chlorine based on the reaction between tetramethylbenzidine (TMB) and free chlorine. The advantages resulting from the use of TMB are considerable: TMB is highly selective for chlorine, it enables a fairly low quantification limit and represents a less toxic alternative to reagents such as tolidine. The...

Absolute quantum yields) Cl+Cl* for the formation of chlorine atoms were measured under collision-free conditions for the gas-phase dissociation of carbon tetrachloride (CCl 4) after pulsed laser photoexcitation at 193 and 135 nm. By means of a photolytic calibration method, where the gas-phase photolysis of HCl was utilized as a reference, values of) Cl+Cl* (193 nm) = 1.5 ± 0.1 and) Cl+Cl* (13...