SPECTROSCOPIC AND ELEMENTAL INVESTIGATION OF MICROBIAL DECOMPOSITION OF AQUATIC FULVIC-ACID IN BIOLOGICAL PROCESS OF DRINKING-WATER TREATMENT

As humic substances left in treated water tend to form trihalomethans during chlorination, their removal in water treatment processes is a s ignificant concern for drinking water supplies. One of the removal tec hnologies, the biofilm reactor is studied for the microbial decomposit ion of aquatic fulvic acid (AFA). The AFA is characterized by elementa l analysis, UV-Vis, C-13-NMR, and IR spectroscopic methods. The spectr oscopic and elemental investigation was capable of characterizing the microbial decomposition of AFA. Biologically treated fulvic acid was i n a more oxidized state; its spectra displayed a higher degree of cond ensation of aromatic constituents than influent fulvic acid. Microbial degradation of AFA was more active in the low molecular weight fracti ons and intensively occurred in the aliphatic fraction.