Dynamics and Removal-Transportation Model of Environmental Trace Organic Compounds in Urban Water Area

点击翻译按钮获取中文摘要

Dynamics of amino acids, nonylphenol and anionic surfactants were investigated in Lake Biwa/Yodo River water system. High sensitive automatic determination method was developed for molybdenum.1. Dynamics of amino acidsMean production rate of total amino acids in northern basin of Lake Biwa was estimated to be 518 mg/m^2/day. About 9 % of this amount was inferred to go down to the hypolimnion as settling particles. Amino acids were decomposed faster than total organic compounds. Amino acids were classified to three groups based on the tendency of the change in their own mole fractions to total amino acid content. The change in mole fraction of the individual amino acid was affected by the bio-geochemical behavior of hard tissue of diatom.2. Dynamics of nonylphenol(NP)NP concentrations in the sediment were at similar level as those reported previously in Japan and other countries, and were at the same order or one order of magnitude lower than the concentrations which induce toxicity to benthic organisms. Particulate NP in Lake Biwa and its tributaries showed a seasonal variation that its concentration was higher in summer than in winter. This would be caused by seasonal change in the activity of microbiological degradation. NP concentration in suspended particles correlated with organic carbon and chlorophyll-a concentration in Lake Biwa.3. Dynamics of anionic surfactantsDissolved amount of anionic surfactants was lower than suspended or settling amount of those in Lake Biwa. Therefore, settling and sedimentation processes were inferred not to be significant ones for the removal of it. Their dissolved concentration was higher in summer than in winter. This seasonal variation was caused by the change in biological activity of micro-organisms.4. Development of automatic determination method for molybdenumHigh-sensitive method for molybdenum in geochemical samples was developed by using a catalytic analysis.