For obtaining fundamental data about the fate of ampicillin （ABPC）, oxytetracycline （OTC）, erythromycin （EM）, and lincomycin （LCM） in water environments, distributions of resistant bacteria, soil adsorption, photodegradation, and removal by duckweed were studied. Against the total population of heterotrophic bacteria in a water sample from Lake Biwa, bacteria resistant to 50 ㎎/L ABPC, OTC, EM, and LCM were, respectively, 4.3, 1.9, 2.5, and 26％. During the soil adsorption test, ABPC and OTC at 10 ㎎/L decreased respectively to 81％ and 15％ in 2 days. Under sunlight, 1.0 ㎎/L OTC and EM decreased respectively to ＜0.5％ and 58％ in 5 days. The duckweed uptake test results showed that 0.1 ㎎/L ABPC and EM decreased respectively to 28％ and 21％ in 7 days. These results demonstrate that LCM was slightly adsorbed to soil, photodegraded, or removal by duckweed, indicating its persistence in water environments.

The electrodeposition of antimony-tellurium binary alloy with thermoelectric conversion properties was attempted in non-aqueous solutions using ethylene glycol（EG）as a solvent. The EG-based electrolytic baths consisted of antimony chloride（SbCl₃）as an antimony ion source and tellurium chloride（TeCl₄）as a tellurium ion source. The composition of the electrodeposits was controlled by the molar ratio of SbCl₃ to TeCl₄ in the bath and the current density. As a result, Sb₂Te₃ was identified by XRD in the electrodeposit obtained at 20Am^－2 in the 97.50 mol% EG-2.45 mol%SbCl₃-0.05 mol%TeCl₄ bath with a SbCl₃ to TeCl₄ molar ratio of 50：1. The composition of the electrodeposit was found to be 42.62 mol%Sb-57.38 mol%Te. The electrodeposit exhibited a p-type thermoelectric conversion for the given temperature difference.

In order to establish a quick and simple analytical method for ammonium nitrogen without using phenol, which is a harmful substance, we developed a method involving continuous flow analysis （CFA）. To prevent interference by metal ions in the sample, ethylenediaminetetraacetic acid （EDTA） was added to the flow. A gas separator using a PTFE membrane filter was used to prevent EDTA interfering with the coloring mechanism and to avoid the effects of foreign substances on the measurement. Only ammonia in the sample is separated by the gas separator in the form of gaseous ammonia and is measured by the salicylic acid indophenol method; this enables analysis without using phenol, and with less susceptibility to inhibiting substances. Both this method and the conventional method using phenol were used to measure samples including seawater and industrial wastewater, and equivalent results were obtained. An evaluation of the method itself confirmed that there was no significant difference from the conventional method. These results suggest that our method offers the same measurement performance as the conventional method and can replace it.

In this study, 13 types of non-precious metal catalysts, such as Fe, Fe₂O₃, Zn, CuO, MnO₂, V₂O₅, MoO₃, Al₂O₃, NiO, Mg, MgO, CaO, and BaO, were evaluated as catalysts to treat ammonia hydrogen peroxide wastewater, such as basic semiconductor washing water that contains high concentrations nitrogen（NH₄-N）and hydrogen peroxide（H₂O₂）, using the subcritical hydrothermal reaction method. In addition, the optimal reaction conditions using the selected catalysts were determined. MgO was selected as the catalyst, and the removal rates of NH₄-N and H₂O₂ were 32.8％ and 100％ under the conditions of simulated wastewater concentrations of 5,000 and 10,000 ㎎/L, respectively, 0.9 g of MgO, a shaking speed of 110 rpm, reaction temperature of 300℃, and reaction time of 1 h. Thus, we demonstrated that MgO has a comparable catalytic performance to Pt for high-concentration nitrogen removal.