Evaluation of thermally treated asbestos based on fiber number concentration determined by transmission electron microscopy

Appropriate treatment of asbestos waste is a significant problem. In Japan, inertization of asbestos-containing waste by novel techniques approved by the Ministry of the Environment is now promoted. A quantitative method of testing with high sensitivity to the asbestos levels present in the inertization products is required for the approval process, but many testing methods are only qualitative. Thus, we have developed an evaluation method for asbestos in inertized products, consisting of the extraction of fibers from inertized products and determination of fiber number concentration by transmission electron microscopy. We adopted this testing method to evaluate thermally treated asbestos. It was found that fiber number concentrations of thermally treated asbestos decreased with increased treatment temperature, and were below the environmental level (10² Mf/g) at more than 1000 °C for chrysotile and crocidolite and more than 1400 °C for amosite and other amphibole forms of asbestos.     

垃圾焚烧飞灰制备高温脱硫剂及其性能评价

利用不同地方的垃圾焚烧飞灰来制备高温炉内的脱硫剂,并利用热天平来研究飞灰脱硫剂(FA-脱硫剂)的固硫性能.实验结果表明,FA-脱硫剂的孔隙分布在2000nm左右,并且比生石灰具有更好的固硫能力.添加石膏后的FA-脱硫剂,其机械强度大大提高,但孔径结构变小,脱硫率也有所下降.添加10%(质量分数)水玻璃的FA-脱硫剂的机械强度相当于生石灰,脱硫效果更明显,比没有添加水玻璃时效果更好,孔径结构基本不变.这是由于水玻璃中的钠跟二氧化硫反应生成钠硫酸盐.     

Profile and removal of endocrine disrupting chemicals by using an ER/AR competitive ligand binding assay and chemical analyses

An estrogen receptor (ER)/androgen receptor (AR) ligand competitive binding assay (ER/AR-binding assay) and chemical analyses were used to evaluate the endocrine disrupting chemicals (EDCs) behavior of two municipal wastewater treatment plants (WWTPs) (K and S). In the influents, estrone (E1), androsterone (A), androstenedione (AD), BPA (bisphenol A), NP (nonylphenol) and daidzein (DZ) were detected in high amounts with subsequent 24 h-average concentrations of 350, 1000, 29, 1300, 3900, and 5700 ng/L in K-WWTP and of 310, 620, 59, 1600, 2600, and 8400 ng/L in S-WWTP. The estrogenic (androgenic) activity as 17 -estradiol (E2) equivalents (EEQ) or testosterone (Te) equivalents (TEQ) was consequently 620 ng E2/L (570 ng Te/L) and 580 ng E2/L (800 ng Te/L) for the two WWTPs. The removal e ciencies of the above mentioned sole target chemicals were 51%–100% for K-WWTP and 55.6%–100% for S-WWTP. The removal e ciencies of EEQ were about 73% for both WWTPs, while the removal e ciencies of TEQ were 62.1% for K-WWTP and 98.4% for S-WWTP. In addition, chemical-derived EEQ were about 1.2%–52.4% of those by ER-binding assay for K-WWTP and the corresponding ratios were 1.3%–83.3% for S-WWTP, while chemical derived TEQ were less than 3% of values measured by the AR-binding assay for both WWTPs.     

Benefit of suites of defensive behavior induced by predator chemical cues on anuran tadpoles, Hyla japonica

When predator chemical cues are present, low activity of prey is a commonly seen defensive behavior. However, few studies have explored the functional implications of the defensive behaviors and, thus, elucidated the possible linkages between behavioral responses and its consequences. In this study, we experimentally investigated how behavioral responses of Hyla japonica tadpoles to predator chemical cues affect vulnerability to a dragonfly nymph Anax parthenope julius. The frequency of tadpoles attacked by dragonfly nymphs was lower with chemical cues of predator was present than without chemical cues, and most of attacks occurred when tadpoles were mobile. When tadpoles were exposed to chemical cues, on the other hand, their swimming speed was quicker and swimming distance was longer, respectively, and the rates of being approached of the swimming tadpoles by dragonfly nymph was lower than those not exposed to chemical cues. We found that the tadpoles are induced by predator chemical cues not only to generally lower activity but also to swim in bursts as additional behavior and that the suite of their behavioral responses reduce the vulnerability against dragonfly nymph. Tadpoles can receive information about the predation risks by chemical cues and adjust their defensive behavior accordingly.     

Effects of light quality on initiation and development of meroplanktonic diatom blooms in a eutrophic shallow sea

We investigated the effects of light quality on resting stage cell germination and vegetative cell growth of meroplanktonic diatoms in a small port in Hakata Bay, Japan and in the laboratory. During the investigation over the year of 2006, the meroplanktonic diatom bloom first occurred in the end of May and then repeated wane and wax until October in the small port. From late April to middle May, light penetrating the water column was often strong and attenuations of all spectral lights were low. During this period, Skeletonema costatum, Thalassiosira minima, and Chaetoceros sp. appeared frequently, followed by the blooms of S. costatum and Chaetoceros sp. in late May. Thereafter, S. costatum and Chaetoceros sp. bloomed in late June but not in middle June, when pigmented flagellates bloom appeared. The attenuation of short-wavelength light such as violet and blue lights was markedly high during these diatom and flagellate blooms; all blooms disappeared within several days. Vegetative cell strains of the three diatoms under light emitting diodes (LEDs) with six different spectra (violet, blue, green, orange, red, and near-infrared) grew at a higher rate under short-wavelength light, violet and blue. On the other hand, when suspensions of bottom sediments from Hakata Bay were cultured under the same LEDs and in the dark, vegetative cells of S. costatum appeared under all LEDs except for orange and near-infrared, vegetative cells of T. minima appeared under all LEDs but not in the dark, and vegetative cells of Chaetoceros sp. appeared under violet and blue LEDs. However, vegetative cell densities of the three diatoms increased much more under violet light than under other LEDs within a short period (6 days). Our study indicates that underwater penetration by short-wavelength light, such as violet and blue, may be an important factor in the initiation and development of meroplanktonic diatom blooms.     

Evaluation by year of the valuable/hazardous material content of lithium-ion secondary battery cells and other components of notebook computer battery packs

Journal of Material Cycles and Waste Management - Our objective was to provide the information necessary to efficiently recover metals from end-of-life lithium-ion secondary batteries by assessing...     

Differences in the Spatial Variability Among CO2, CH4, and N2O Gas Fluxes from an Urban Forest Soil in Japan

The spatial variability of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) fluxes from forest soil with high nitrogen (N) deposition was investigated at a rolling hill region in Japan. Gas fluxes were measured on July 25th and December 5th, 2008 at 100 points within a 100 × 100 m grid. Slope direction and position influenced soil characteristics and site-specific emissions were found. The CO₂ flux showed no topological difference in July, but was significantly lower in December for north-slope with coniferous trees. Spatial dependency of CH₄ fluxes was stronger than that of CO₂ or N₂O and showed a significantly higher uptake in hill top, and emissions in the valley indicating strong influence of water status. N₂O fluxes showed no spatial dependency and exhibited high hot spots at different topology in July and December. The high N deposition led to high N₂O fluxes and emphasized the spatial variability.     

Study of Hg and SO3 behavior in flue gas of oxy-fuel combustion system

Oxy-fuel combustion systems have been under development to reduce CO₂ emissions from coal-fired power plants. In oxy-fuel combustion system, Hg in the flue gas causes corrosion in CO₂ purification and compression units. Also, SO₃ in the flue gas corrodes the equipment and ducts of oxy-fuel combustion system. Therefore, Hg and SO₃ need to be removed.Babcock-Hitachi conducted tests using a 1.5 MWth Combustion & Air Quality Control System (AQCS) test facility which consists of oxygen supply unit, furnace, Selective Catalytic Reduction (SCR) catalyst, Clean Energy Recuperator (CER), Dry Electrostatic Precipitator (DESP), flue gas recirculation system, Wet Flue Gas Desulfurization (WFGD), and CO₂ Compression and Purification Unit (CPU). In both cases of air and oxy-fuel combustion, the Hg removal across the DESP could be improved, and SO₃ concentration at the DESP outlet could be reduced to less than 1 ppm by installing a CER upstream of the DESP and reducing the gas temperature at the DESP inlet. Hg was not dissolved in the drain recovered from CO₂ compressor, and may be adsorbed at an inner part of CO₂ compressor. This indicated that Hg needs to be removed at a location upstream of the CO₂ compressor to prevent corrosion of the compressor.     

The sensitivity of carbon sequestration to harvesting and climate conditions in a temperate cypress forest: Observations and modeling

The role of disturbance and climate factors in determining the forest carbon balance was investigated at a Japanese cypress forest in central Japan with eddy flux measurements, tree-ring analyses, and a terrestrial biosphere model. The forest was established as a plantation after intermittent harvesting and replanting between 1959 and 1977, and acted as a strong carbon sink of approximately 500 g C m⁻² year⁻¹ for the measurement years between 2001 and 2007. A terrestrial biosphere model, BIOME-BGC, was validated using the eddy flux data at daily to interannual timescales, and the tree-ring width data at interannual to decadal timescales. According to the model simulation, during the observation period 270 ± 55 g C m⁻² year⁻¹ was additionally sequestered due to the indirect effects of the harvesting and planting, whereas the increase of CO₂ concentration and the change in climate increased the sink of 110 ± 40 and 30 ± 80 g C m⁻² year⁻¹, respectively. The model simulation shows that the forest is now recovering from harvesting, and that harvesting is a more important determinant of the current carbon sink than either interannual climate anomalies or increased atmospheric CO₂ concentration. We found that harvesting with long rotation length could be effective management activity in order to increase carbon sequestration, if the harvested timber is converted into products with long lifecycles.