To establish a method for removing residual chlorine and trihalomethanes from hot water effectively, an activated carbon column was placed in an electric pot. The variation in concentrations of those compounds was measured by altering the setting position of the activated carbon column and the flow rate of the test solution in the column.
Activated carbon was found to act as a catalyst of the decomposition of residual chlorine. Removal capability based on decomposition decreased with increase in space velocity, and increased with temperature rise. Although activated carbon serves as adsorbent for the removal of trihalomethanes, the amount of trihalomethanes absorbed in activated carbon was quite small in hot water.
The efficiency of residual chlorine removal was low when the activated carbon column was placed at the bottom of the pot. To realize a greater efficiency of the removal, a higher flow rate of test solution through the activated carbon column was required. When the column was placed at the outlet of solution circulation pipe, considerable part of residual chlorine was removed. As a consequence of removing residual chlorine the generation of trihalomethanes was prevented. The concentration of trihalomethanes in solution decreased when the solution was kept hot. The lifespan of activated carbon is very long since it acts as catalyst but not as adsorbent.

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Major sources and behaviors of volatile organic compounds (VOCs) in the indoor air were studied in newly built houses. The measurements were carried out in six newly built houses located in Tsukuba area in 1998, starting before the users began to use and then continued monthly during six months. High concentrations of volatile organic compounds, such as toluene and xylenes originated from interior materials made of synthetic chemicals and terpines originated from woody materials, were observed in all the houses and their concentrations decreased with time. The emission rates of the VOCs decreased constantly during 4-6 months. The concentrations of xylenes decreased faster than those of toluene.

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Polychlorinated dibenzo-p-dioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs) and coplanar PCBs (Co-PCBs) were determined in 16 liver samples of common cormorant that inhabits in and around Tokyo Bay, Japan. Average PCDD/Fs concentrations were found to be 33, 000 pg/g fat wt. Among PCDD/Fs congeners, 2, 3, 7, 8-substituted compounds occupied about 90 % of total PCDD/Fs in all samples. Especially, 1, 2, 3, 7, 8-PeCDD and 2, 3, 4, 7, 8-PeCDF were the main contributors. Fish samples collected from Tokyo Bay showed a similar isomer profiles to those of cormorant liver. The results indicated that the fish played a significant role in elevated exposure to the cormorants. Biomagnification factor (BMF) of PCDD/Fs ranged from 0.82-1.4 of 2, 3, 7, 8-TCDF to 130-380 of 2, 3, 4, 7, 8-PeCDF BMF of Co-PCBs showed somewhat higher values than those of PCDD/Fs, i.e., from 5.6-32 of CB77 (IUPAC No.77) to 320 1900 of CB169. Toxic equivalency (TEQ) was calculated using WHO-Birds TEE Altogether, TEQ in cormorants was estimated as 27, 000 pgTEQ/g fat, and 1, 2, 3, 7, 8-PeCDD (13 %), 2, 3, 4, 7, 8-PeCDF (36 %) and CB126 (28 %) contributed greatly. 1, 2, 3, 7, 8-PeCDD was particularly higher in present study when compared with reported level in the cormorant of the Netherlands.

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In this study, both the change of removal efficiency according to operation time and decomposition of Dioxins by heating were investigated on the removal of Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans=PCDD/DF) in exhaust gas of incinerator by fly ash-derived artificial zeolite. The removal rates calculated by TEQ value of vapor PCDD/DF in exhaust gas of small size incinerator were as follows: 98.7 % at the initial operation and 91.8 % after 300 hours (at 150°C, 10000 h^-1 as SV value) . The relatively low removal rate after 300 hours was due to the decreasing adsorption of low chlorinated PCDD/DF-congeners. Highly efficient decomposition (about 99 %) of adsorbed chlorinated PCDD/DF-congeners were found in used artificial zeolite after heating for one hour at 300-350°C in nitrogen gas atmosphere.

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The sampling method for polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and coplaner polychlorinated biphenyls (Co-PCBs) in water based on coagulant with fast sedimentation and filtration was studied. It was found that recovery rates of PCDD/Fs and Co-PCBs were from 73% to 119% and from 79% to 107%, respectively. No significant effect by surfactant in water was found on the recovery rates of PCDD/Fs and Co-PCBs. Moreover, concentrations and compositions of PCDD/Fs and Co-PCBs in river water samples from Matsuyama by coagulant method were nearly equal to those by ODS method. It was found that this coagulant method stands comparison with ODS method, and that this will be useful for the analysis of PCDD/Fs and Co-PCBs in water samples.

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An analytical method using carbonaceous resin as an adsorbent was examined for determination of volatile organic compounds (VOCs) in soil gas. The compounds adsorbed on the resin were desorbed by heating at 280°C and analyzed simultaneously by GC/MS. The sensitivity of this method is 1000 times higher than the method with n-hexane trap or commercial detector tube. This method was applied to the determination of tetrachloroethylene (PCE) in a field. The PCE could be measured below the detection limit of commercial detector tube analysis. The method was also used to analyze VOCs in a region of Fukuoka city for search of an unknown pollution site. The area was divided by a 2 km mesh and the soil gas was collected in each square. The concentrations of 1, 1, 1-trichloroethane and trichloroethylene (TCE) in the soil gas were higher than those in the atmosphere at several points, suggesting pollutions of soil or groundwater with these compounds.

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The concentration of trihalomethanes in the gas phase equilibrated with a liquid phase increased with temperature. Moreover, the concentration of CHCl₃, a main compound of trihalomethanes in tap water originated from river water, in the gas phase was higher than that in the liquid phase at 90°C .
While blowing air into heated water, trihalomethanes in an electric thermo-pot transferred fast from liquid to gas phase due to the increase of the contact area. It is necessary to discharge the gas containing trihalomethanes outside of the pot in order to remove trihalomethanes effectively.
In the initial period of use activated carbon adsorbed trihalomethanes in heated water. Activated carbon with a wide distribution of pore diameter could not fully desorb trihalomethanes adsorbed, but that with a narrow distribution of pore diameter of about 1.4 nm could desorb almost completely at about 100°C. Therefore, the activated carbon with the narrow distribution of pore diameter had a long lifetime for the removal of trihalomethanes.
The activated carbon was able to adsorb 2-methyl-isoborneol in heated water, and it kept the adsorptivity for a long time if the concentration of 2-methyl-isoborneol was about 100pg/l.

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A porous cellulose tape impregnated with a processing solution that includes N, N-Diethyl-p-phenylenediamine (DPD) sulfate, glycerin and methanol was developed for the detection of chlorine gas in air. When the sample is passed through the tape, chlorine reacts with DPD to form a red stain. The intensity of the red stain is proportional to the concentration of chlorine at a constant sampling time and flow rate, and was recorded by measuring the intensity of reflected light (555 nm) . The detection limit was 0.03 ppm of chlorine with a sampling time of 60 s and a flow rate of 200 ml min^-1. The sensitivity of the tape could be maintained for at least 1 month when stored in dark clean box.
Reproducibility tests showed that the relative standard deviations of the response (n=10) was 2.5 % for 0.1ppm of chlorine gas. No interference was observed from ethanol (1 vol.%), acetone (1 vol.%), trichloroethylene (1 vol.%), carbon monoxide (100 ppm), hydrogen sulfide (30 ppm), sulfur dioxide (51 ppm) or ozone (2 ppm) .
The relative intensities of nitrogen dioxide and fluorine gas were 25 and 13 % of that of chlorine, respectively.

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