• Inicio
  • Resultados de la búsqueda
  • Formation of trichloronitromethane and dichloroacetonitrile in natural waters: precursor characterization, kinetics and interpretation.

Formation of trichloronitromethane and dichloroacetonitrile in natural waters: precursor characterization, kinetics and interpretation.

Journal of hazardous materials (2014-10-04)
Yi-Hsueh Chuang, Hsin-Hsin Tung
RESUMEN

During the chloramination of natural waters, both chloramines and dissolved organic nitrogen (DON) can serve as nitrogen sources for the formation of trichloronitromethane (TCNM) and dichloroacetonitrile (DCAN). The present study investigated the formation kinetics and precursor characteristics of TCNM and DCAN. (15)N-Isotopic monochloramination of the organic fractions produced both (15)N- and (14)N-DCAN and TCNM. Nitrogenous disinfection byproduct (N-DBP) formation, in which the nitrogen precursor originated from DON ((14)N-DCAN and (14)N-TCNM), followed a second-order reaction kinetics (k=3.2×10(-5) to 9.4×10(-5)μM(-1)h(-1)). The formation of N-DBP where the nitrogen atoms originated from chloramines (e.g. (15)N-DCAN and (15)N-TCNM) correlated linearly with chloramine exposure. The discrepancy in formation kinetics results in that the (14)N-DCAN concentrations were two to ten times higher than (15)N-DCAN in the beginning of the reaction (<12h). Possible rate equations are proposed in this study. The results of a model compound study support the results of the chloramination of natural waters. In addition, 4-hydroxybenzaldehyde, an oxidative product commonly found during chlorination/chloramination of natural organic matters, gave a 10-fold greater yield of DCAN than that produced from tyrosine; 4-hydroxybenzaldehyde is thus an important precursor in DCAN formation by chloramine incorporation during the chloramination of natural waters.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Sodium hypochlorite solution, reagent grade, available chlorine 10-15 %
Sigma-Aldrich
tert-Butyl methyl ether, anhydrous, 99.8%
Sigma-Aldrich
Sodium hypochlorite solution, reagent grade, available chlorine 4.00-4.99 %
Sigma-Aldrich
tert-Butyl methyl ether, suitable for HPLC, ≥99.8%
Sigma-Aldrich
L-Tyrosine, reagent grade, ≥98% (HPLC)
Sigma-Aldrich
tert-Butyl methyl ether, ACS reagent, ≥99.0%
Sigma-Aldrich
tert-Butyl methyl ether, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%
Sigma-Aldrich
4-Hydroxybenzaldehyde, 98%
Sigma-Aldrich
Chlorine, ≥99.5%
Sigma-Aldrich
tert-Butyl methyl ether, reagent grade, ≥98%
Sigma-Aldrich
Nitrogen, ≥99.998%
Sigma-Aldrich
L-Tyrosine, from non-animal source, meets EP, USP testing specifications, suitable for cell culture, 99.0-101.0%
Sigma-Aldrich
N,N-Diethyl-p-phenylenediamine, 97%
Sigma-Aldrich
L-Tyrosine, BioUltra, ≥99.0% (NT)
Sigma-Aldrich
4-Cyanophenol, 95%
Sigma-Aldrich
Sodium hypochlorite solution, 6-14% active chlorine basis
SAFC
L-Tyrosine
Supelco
L-Tyrosine, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
tert-Butyl methyl ether, analytical standard
Sigma-Aldrich
tert-Butyl methyl ether, puriss. p.a., ≥99.5% (GC)
Sigma-Aldrich
4-Hydroxybenzaldehyde, ≥97%, FG
Supelco
tert-Butyl Methyl Ether, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
tert-Butyl methyl ether, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%
USP
L-Tyrosine, United States Pharmacopeia (USP) Reference Standard
Sigma-Aldrich
L-Tyrosine, FG
Sigma-Aldrich
4-Hydroxyphenylacetonitrile, 98%
Sigma-Aldrich
4-Hydroxybenzaldehyde, ≥95.0% (HPLC)
Sigma-Aldrich
tert-Butyl methyl ether, reagent grade, 98%
Supelco
L-Tyrosine, certified reference material, TraceCERT®
Supelco
tert-Butyl methyl ether, suitable for HPLC, ≥99.8% (GC)