Extraction and cleanup methods of dioxins in house dust from two cities in Japan using accelerated solvent extraction and a disposable multi-layer silica-gel cartridge

A simple and rapid method for the extraction and cleanup of dioxins from house dust was developed using an accelerated solvent extraction (ASE) method and a multi-layer silica-gel cartridge. It was found that the WHO-TEQ levels of dioxins extracted from the house dust obtained by both a conventional soxhlet extraction and the ASE were almost equal, when the data obtained by both methods were compared. As for the cleanup method, a multi-layer silica-gel cartridge yielded higher dioxin recoveries than the alkaline digestion method. The average values of the dioxins in house dust from Kumagaya city and Sendai city in Japan (Sendai city is bigger than Kumagaya city with respect to the population and industry), were 15.6 pg TEQ/g (8.6-26.0 pg TEQ/g, n=5, Kumagaya city) and 16.0 pg TEQ/g (5.9-30.5 pg TEQ/g, n=5, Sendai city), respectively.     

Investigation into the relationship between major and minor element contents and particle size and leachability of boron in fly ash from coal fuel thermal power plants

A basic investigation of boron in discharged fly ash by coal fuel thermal power plants in several worldwide locations was carried out. Eight kinds of fly ash sample were prepared from eight coal fuel thermal power plants. Two of the fly ash samples were used to examine the relationship between the concentration of boron in fly ash and the particle size. When the particle size of fly ash is smaller, there is a possibility that it will be released into the air and spread over a wide area in the environment. However, it has become apparent that fly ash of smaller particle size has a higher concentration of boron and a higher enrichment factor. In other fly ash samples, the boron contents were examined and leaching tests were carried out. There is acidic fly ash as well as alkaline fly ash that contains larger amounts of acidic or basic salts. On alkaline fly ash, when the concentration of boron bound to Fe-Mn oxide is low; it has become apparent that leaching boron is increased in a solution with lower pH of approximately 4 which is nearly the pH of acid rain.     

Aerosol Number Concentrations during Kosa Events on Suburban Hills in Japan

Measurements of aerosol size-separated number concentrations were performed in March 2001 on the Tama Hills of Japan, located near regions of heavy industry. The concentrations of particles larger than 1.0 μ m in diameter dramatically increased during the Kosa phenomena on 6–8 and 18–24 March. The number concentrations of coarse particles (> 3.0 μm) showed distinct diurnal variations, especially during the Kosa events. Fine particles smaller than 0.5 μm increased when the relative humidity was high and the wind speed was low. On the other hand, the coarse particles concentrations were well correlated with wind speed and temperature. The dry deposition velocity of the coarse particles at the forest canopy was estimated from the nighttime decrease in the number concentrations.     

A method for regional-scale material flow and decoupling analysis: A demonstration case study of Aichi prefecture, Japan

We have developed a method to analyse the annual material flow in a prefecture and have calculated environmental indicators for a prefecture. Material flow analysis (MFA) is important to clarify the structure of a regional society and obtain environmental indicators for a circular society. However, MFA has not advanced in local governments because of few local statistics. We have developed a method to analyse the annual material flow in Aichi prefecture from 1980 to 2000 using an input–output (I–O) table and statistics of Aichi. We have verified the accuracy of this method by comparing its results for 2000 which calculated on the basis of official I–O table for 1995 with the I–O table data for 2000; the correlation coefficient obtained in this case is greater than 0.95. Moreover, by performing MFA, we have estimated the resource consumption and decoupling indicator of each industry in Aichi prefecture from 1980 to 2000. We could obtain more detailed and accurate environmental indicators by using our method. From these results, we could estimate the progress of Aichi prefecture towards a circular society.     

SIMULATED EFFECTS OF ALTERED SPILLWAY RELEASES ON THERMAL STRUCTURE AND KOKANEE GROWTH IN A COLORADO RESERVOIR1

ABSTRACT: In‐reservoir thermal and ecological effects of releasing some flows over the surface spillway at Blue Mesa Reservoir, Colorado, rather than routing all releases through the hypolimnetic outlet were evaluated using a calibrated and validated one‐dimensional thermal model (CE‐THERM) with a set of ecological models. Thermal model output indicated that surface water temperatures were influenced primarily by atmospheric conditions, but the release of warmer water over the spillway resulted in a thinner epilimnion and cooler metalimnetic water temperatures. Ecological model predictions indicated that spillway releases and associated temperatures resulted in lower growth rates for young‐of‐year (YOY) kokanee salmon (Oncorhynchus nerka) in the reservoir by up to 9 percent when compared with growth rates under baseline operations with no releases over the spillway. Kokanee growth rates were reduced under spillway release scenarios because lower temperatures not only affected metabolic rates, but limited the productivity of the zooplankton as well. Thus, altering the release regime with spillway discharges could have deleterious effects on Blue Mesa's YOY kokanee. However, in other reservoirs, distributing discharges among different elevations may provide managers with a mechanism to regulate temperatures to benefit species of concern that are facing challenges imposed by environmental conditions such as global warming.     

Behavior of potassium in bread by ion chromatography

Public attention was aroused when mutagenicity was found in potassium bromate (KBrO₃) which has been used as an oxidizing agent in baking bread. Ion chromatography was found to be very useful for analyzing bromide and bromate ions in food. The residual condition of potassium bromate added to bread in the baking process was clarified.It was found that the residual rate of bromate ions in bread was approximately 30% at the added level of 100 μg/g, but it decreased markedly when the added levels went down. At 40 μg/g no residue was detected.     

Immobilization of B,F, Cr,and As in alkaline coal fly ash through an aging process with water

Fourteen different alkaline coal fly ashes (CFAs) were used for the experiment, in which each sample was mixed with water to be 28.6 % of water content (wt/wt) and aged for 1–4 weeks at 10–30 °C. This simple treatment is advantageous for decreases in water-soluble B, F, Cr, and As. Compared to non-aged CFAs, their water-soluble fractions remained 0.56–88 %, 21–85 %, 0.37–93 % and 2.6–88 %, respectively, after aging for a week at 20 °C, although the amounts of Cr and As released from some CFA samples increased. Considering the significant decrease in elution of sulfate, Ca and Al after aging, the immobilization, namely prevention of toxic element elution, could be related to formation of secondary minerals such as portlandite, gypsum and ettringite. Immobilization of B and Cr tends to proceed preferentially under colder conditions. Aging at higher temperatures enhances the leachability of Cr in some CFA samples. Contrary to the behavior of B and Cr, water-soluble F effectively decreases under warmer conditions.     

An assessment of global warming and biodiversity: CGE EMEDA analyses

Environmental Economics and Policy Studies - Genetic resources have been widely used for agricultural animal breeding, drug development, and biomaterials. Coherent assessments of global warming on...