Previous studies modeled NDMA formation during chlorine disinfection as arising from the oxidation of an unsymmetrical dimethylhydrazine intermediate formed from the reaction of monochloramine and dimethylamine. However, chlorination of wastewater effluents indicated that this mechanism could not account for a significant portion of the observed NDMA formation. Laboratory studies indicated that...

Chlorination has been the major strategy for disinfection of drinking water in Taiwan. An ecologic epidemiological study design was used to examine whether chlorination of drinking water was associated with cancer risks. A "chlorinating municipality" (CHM) was defined as one in which more than 90% of the municipality population was served by the chlorinated water while an "nonchlorinating munic...

Factorial experiments were conducted to investigate the effect of chlorination filtrate recycle on toxicity and organically bound chlorine in the first two stages of softwood kraftpulp bleaching. The effects of the mode of chemical addition, the substitution of chlorine dioxide, and the kappa factor were also studied. A continuous laboratory-scale (6.0 o.d.g/min) chlorination apparatus was desi...

The formation of chlorination by-products (CBPs) was investigated by bench-scale chlorination experiments with surface waters from different sources in Lesvos island, Greece. The main factors studied were organic matter content of water (expressed as UV-272 absorbance), time and chlorine dose. The CBPs, determined by gas chromatographic techniques, belong to the categories of trihalomethanes (T...

Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evaluated. In the kinetic study, the second-order rate constant (kapp) for the reaction between Mfe and...

In this study, a novel chlorination technique for metallic titanium (Ti) was devised in order to establish a recycling process that uses both Ti metal scrap and iron chloride (FeClx) waste, and its feasibility was demonstrated. Direct reaction between Ti and FeClx has drawbacks such as slow kinetics of Ti chlorination and high volatilization of FeClx. To overcome these, the authors proposed a c...