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...

N-Nitrosodimethylamine (NDMA) is a member of a family of extremely potent carcinogens, the N-nitrosamines. Until recently, concerns about NDMA mainly focused on the presence of NDMA in food, consumer products, and polluted air. However, current concern focuses on NDMA as a drinking water contaminant resulting from reactions occurring during chlorination or via direct industrial contamination. B...

A direct viable counting method was used to rapidly assess the effectiveness of chlorination of biofilms on rapid sand filter gravel. A total of 50% of the cells were nutrient responsive after exposure to 0.5 mg of chlorine per liter, while this value was 25% after exposure to 25 mg of chlorine per liter. A large variation was seen in the numbers of nutrient-responsive cells on different rocks....