Chlorination Byproduct Formation in the Presence of Humic Acid, Model Nitrogenous Organic Compounds, Ammonia, and Bromide

Abstract

The formation of trihalomethanes (THMs), haloacetic acids (HAAs), and cyanogen halides (CNXs) after chlorination of synthetic solutions containing humic acid, nitrogenous organic (N-organic) compounds, ammonia, and bromide ions was studied. Humic acid (from Aldrich) was used to provide the source of the precursors. Glycine was chosen as the primary model N-organic compound and other four model N-organic compounds (including glutamic acid, glycylglycine, diethylamine, and methylamine) were also evaluated for comparison. The formation of THMs and HAAs was found to decrease with increasing glycine and ammonia concentrations but to increase with increasing bromide ion concentration. CNX formation was found to be highly sensitive to free chlorine to glycine ratios, and its formation trends were significantly affected bythe presence/absence of ammonia. The incorporation of bromine changed the byproducts speciation toward brominated species and enhanced the yields of total THMs, HAAs, and CNXs. Different model N-organic compounds exerted different effects on the formation of THMs, HAAs, and CNXs. Their effects on the formation of THMs and HAAs were likely dependent on their reactivity to chlorine in competing with the humic acid chlorination reactions. The difference in the CNCI yields was attributable to the variations in the compound structures.

Clay Ceramic Filter for Water Treatment

“…Some of these techniques reduce the quality of water, and the side-products have an adverse effect on consumer health. Chlorine in water combines with natural organic compounds to yield substances such as trihalomethanes, haloacetic acids, and chlorophenols that exhibit potentially carcinogenic, teratogenic and mutagenic activities [6]. Ceramic water filtration is the process of passing water through a porous ceramic material.…”

Cu(II)-catalyzed THM formation during water chlorination and monochloramination: A comparison study

“…A number of organics have been identified as THM precursors, such as HA [10], organic nitrogen compounds [11], citric acid [12], methyl ketones [13], algal cells [14], and hydroxybenzene [15]. HA is a main precursor with a complex macromolecule containing aromatic heterocyclic rings that are commonly substituted with methoxy (OMe), hydroxyl (OH), carboxylic (COOH), and other functional groups [16].…”

Enhanced destruction of Cu(CN)32− by H2O2 under alkaline conditions in the presence of EDTA/pyrophosphate

“…By contrast, cyanides could be directly converted into less harmful products by employing oxidation methods, such as ozonation [7], electrochemical oxidation [8,9], photocatalysis [10,11], ferrate oxidation [12,13] and wet oxidation [14]. The most practical method was thought to be alkaline chlorination, but it has many disadvantages such as formation of toxic cyanogens chloride [15] and chloride disinfection by-products [16].…”