Chlorination Of Humic Acid Research Articles

Effects of chemical and physical treatments on the stability of halogenated organic compounds in water

Methods of preservation of total organic halides (TOX) formed from chlorinated humic acid were investigated using physical and chemical treatments in stability tests. An acid treatment (pH 2.0) was more effective than treatment with bactericides (azide or molybdate) in preventing TOX loss in water samples. TOX derived by chlorination of humic acid was more resistant than trichloroacetic acid (TCA) to heat treatment (autoclaving). Loss of humic TOX occurred upon filtration of the sample, whereas no decrease in TCA concentration was evident. 44% of humic acid‐derived TOX was detected as nonpurgeable organic halides (NPOX) and the rest 56% was purgeable organic halides (POX), largely trihalomethanes (THM).

On the formation of mutagens in the chlorination of humic acid

Deux produits mutagenes sont etudies: l'acetone dichloro et le propenal monochloro. Ils se forment a de faibles concentrations en acide humique durant la chloration

Chlorination Products of Humic Acid (Panel Discussion Mechanism of Trihalomethane Formation) (Proceedings of the 8th Symposium on Environmental Pollutants and Toxicology)

Reaction mechanism of humic acids of different origins with chlorine were studied. Volatile chlorinated substances produced by chlorination of humic acid were identified, and possible formation mechanism of one of these substances, chloropicrin, was investigated. Two kinds of humic acids showed different patterns of formation of chloroform and the other chlorinated substances under various conditions for chlorination. High performance liquid chromatography, Sephadex gel chromatography and infrared spectrophotometry of humic acid and chlorinated one demonstrated that these differences are derived from different functional groups in a molecule of humic acid, and that, in addition, humic acid is decomposed to lower molecular weight substances having molecular weight of about several thousands and higher chloroform formation potential. Volatile chlorinated substances were identified to be chloropicrin and carbon tetrachloride besides chloroform by GC-MS with a computerized data system. Precursors for the chloropicrin formation were amino acids such as alanine, threonine, ornithine, glutamic acid and glycine ; nitro- or nitrosophenols ; nitro- or nitrosoresorcinols ; nitromethane and nitroethane. Chloropicrin was produced by chlorination of humic acid and resorcinol in the presence of nitrite. As for mechanism of chloropicrin formation by chlorination of resorcinol in the presence of nitrite, it was recognized that nitroso-substitution of resorcinol occurred in the presence of nitrite and produces nitrosoresorcinol, which was oxidized to nitroresorcinol with hypochlorite, and finally nitroresorcinol formed chloropicrin by the method of the Rook's reaction of chloroform formation from resorcinol.

低沸点有機塩素化合物の生成機構に関する研究 ＩＩ フミン酸の塩素処理時におけるクロロホルム生成に対する共存金属の影響について

Chloroform formation by chlorination of humic acid in the presence of different metals were investigated.The following results were obtained.(1) Fe2+, Sn4+, Cr2O72-, Ni2+, SeO42- and Pb2+ had no effect on chloroform formation by chlorination of humic acid.(2) Mn2+, SeO32- and Co2+ decreased chloroform formation, because these metals consumed an available chlorine demanded in chloroform formation of humic acid. However, MnO4- decreased chloroform formation because permanganate oxidized humic acid.(3) Cu2+, Al3+, Fe3+ and Zn2+ accelerated chloroform formation because of catalyst-like function, the efficiency being in the decreasing order Cu2+> Al3+> Fe3+> Zn2+.