Journal of Ecotechnology Research
Online ISSN : 1884-0388
Print ISSN : 1881-9982
ISSN-L : 1881-9982
17 巻, 1 号
選択された号の論文の9件中1~9を表示しています
Original Article
  • CHEN Bin, YAMADA Maromu, SHI Guangyu, ZHANG Daizhou, MATSUKI Atsushi, ...
    2013 年 17 巻 1 号 p. 1-9
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    Vertical structures of aerosols from the ground to about 1000 m altitude in Beijing were measured with a balloon-borne optical particle counter. The results showed that, in hazy days, there were inversions at approximately 500-600 m, below which the particulate matters were well mixed vertically while the concentration of particles decreased sharply above the mixing layer. Electron microscopic observation of the particles collected with the balloon borne impactor indicate that the composition of particles are different according to weather conditions in the boundary mixing layer of Beijing city, and suggest that dust particles are always dominant in coarse mode particles. Interestingly sea salt particles are frequently identified suggesting the importance of marine air inflow to the Beijing area even in summer. The Ca rich and spherical particles are also frequently identified suggesting chemical modification of dust particle by NOx or emission of CaO and others from local emission. Additionally those types of particles showed higher concentration above the mixing layer under the relatively calm weather condition of summer suggesting the importance of local scale convection found in summer which rapidly transported anthropogenic particles above the mixing layer. Lidar extinction profiles qualitatively have good consistency with the balloon-borne measurements. Attenuation effects of laser pulse intensity are frequently observed due to high concentration of particulate matter in the Beijing atmosphere, and therefore quantitative agreement of lidar return and aerosol concentration can be hardly observed during dusty condition. Comparing the depolarization ratio obtained from the lidar measurements with the balloon-borne measurements the contribution of the dry sea-salt particles, in addition to the dust particles, is suggested as important factor causing depolarization ratio in the Beijing atmosphere.
  • SERIKAWA Yuka, ROSANA Elvince, KAWAKAMI Tomonori, KUNORI Noriyasu, NOT ...
    2013 年 17 巻 1 号 p. 11-15
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    The mercury concentrations in the atmosphere and in rivers were measured in the Krueng Sabee town Aceh Jaya District in Indonesia where a small-scale gold mining was heavily done on July 2010. The gaseous mercury concentration was measured with the simultaneous use of passive samplers, recently developed for multi-point sampling, and active samplers. Nine passive samplers were placed in the gold mine and along the main street of the town. Seven water samples from the Krueng Sabee River and its tributaries, two samples from a water treatment plant that supplies water to the town before and after the treatment, and two samples from wells were taken to determine the total mercury concentration. The highest concentration of gaseous mercury was found in the plant, 1,740 ng m-3; this value was higher than the WHO guidelines and the Japanese Environmental Standard of 1,000 ng m-3and 40 ng m-3, respectively. The highest mercury concentration among the water samples was found in well water, 78 ng L-1; this value was much lower than the WHO guidelines and the Japanese standard for drinking water of 1,000 ng L-1 and 500 ng L-1, respectively. The adverse effect of gaseous mercury on the health of the workers is a concern.
  • SUDHARMA Yatigammana, BUDDHIKA Perera, NAMAL Atukorala
    2013 年 17 巻 1 号 p. 17-22
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    The current study investigates the patterns of the changes of the physicochemical characteristics in 58 relatively shallow, eutrophic reservoirs of Sri Lanka during the wet (rainy) and dry seasons. These reservoirs range in values of specific conductance from 17 to over, 920 μS/cm during the dry season and 16 to over, 630 μS/cm during the wet season and can also be described as slightly alkaline, eutrophic systems. The reservoirs examined are located in four climatic regions [Arid, Dry, Galoya Basin (dry zone), Intermediate, and Highland Wet zones] of Sri Lanka that vary according to, for example, patterns of precipitation, evaporation and seasonality. Results of the study clearly indicate that the specific conductance and related variables reflect the patterns in precipitation and evapoconcentration. The highest specific conductance values are found in the Arid and Dry Zones (average concentrations of 586 and 274 μS cm-1) during the dry season, and are sequentially lower in the Intermediate and Highland Wet zones. Interestingly, reservoirs in the Gal-Oya basin (Dry Zone) also record low specific conductance with the average values 81 and 58 μS cm-1 during both dry and wet seasons. The average dissolved oxygen was higher during the dry season in all the regions except in Highland Wet Zone. The concentration and gradient of important nutrients (e.g. ammonia-N, total phosphorus and dissolved phosphorus) show marked variation during wet and dry seasons having higher values especially during the wet season. Pearson correlation analysis shows that a concentration of total phosphorus is strongly related to chlorophyll a confirming the phosphorus is the limiting factor for algal growth within the study reservoirs
  • MADHUSHANKHA Liyanage, DHAMMIKA Magana-Arachchi, NADUWILADATH Chandras ...
    2013 年 17 巻 1 号 p. 23-28
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    Cylindrospermopsin (CYN) is one of the potent cyanotoxin which affects the functions of kidney and liver. This study was performed to identify CYN in Anuradhapura water reservoirs using molecular and biochemical methods. Water samples were collected from Kala wewa, Nuwara wewa, Tissa wewa and Jaya ganga. Under microscope, Cylindrospermopsis species were recorded as the dominant cyanobacterial species along with Microcystis, Anabaena, Chroococcus, Phormidium, Oscillatoria, which were comparatively moderate to low. In molecular detection, the presence of cyanobacteria, the presence of Cylindrospermopsis and Cylindrospermopsis strains that have the genetic potential to produce CYN were detected using specific PCR primers targeting 16S rRNA gene, C. raciborskii specific cylindrospermopsin synthetase gene and cylindrospermopsin specific peptide synthase (PS) gene respectively. The presence of toxin producing Cylindrospermopsis raciborskii in those water samples was reconfirmed by a nested PCR using C. raciborskii specific primers cyl2, cyl4 and cyl-int and by direct sequencing. Further, ELISA detection kit confirmed the presence of CYN and the toxin concentration. All were positive for CYN with mean concentrations of 0.104, 0.091, 0.255 and 0.0967 ng/ml for Jaya ganga, Kala wewa, Nuwara wewa and Tissa wewa respectively. Water samples collected from water purification centre in Anuradhapura showed 0.245 and 0.154 ng/ml of CYN before purification and after addition of chlorine respectively.
  • Precautionary Measures for Environmental Impact Management at Harbor Development: Galle Harbor Sri Lanka
    MALAVIPATHIRANA S, MUBARAK MNA, PERERA KMPAH
    2013 年 17 巻 1 号 p. 29-33
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    Marine sediments of inner Galle harbor, Sri Lanka were analyzed for nine heavy metals before commencement of the harbor development activities. Microwave digestion and slurry preparation methods were adopted for sample preparation in order to investigate the best and convenient methods for the total metal recoveries. Microwave digestion procedure exhibits higher metal recoveries of which concentrations of Pb and Ni at some locations and Hg at all the locations exceed ISQG lower trigger values (Pb - 50 mg/kg, Ni - 21 mg/kg, Hg - 0.15 mg/kg). The results confirmed heavy metal pollution of all the locations studied while the most polluted locations belong to navigational areas and closer to city canal outlet.
  • CHANDIMA Bandara, NAMAL Priyantha
    2013 年 17 巻 1 号 p. 35-38
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    The extent of removal of Cd(II) by natural peat available in Muthurajawela, Sri Lanka, is very low, suggesting the need for its modification to enhance the interaction ability towards this metal ion. However, thermal modification does not lead to a significant improvement of Cd(II) removal, indicating that the organic matter and other surface functionalities present in peat do not contribute to the removal of Cd(II). Interestingly, chemical modification of peat (fired at 200 °C) performed by treatment with nitric acid is able to improve the transfer of Cd(II) from the solution phase to the solid peat phase. During acid treatment, it is expected that protonation of surface functional groups of the adsorbate, such as carboxyl (COOH) and hydroxyl (OH), and solubilisation of metal complexes and metal oxides occur, promoting the extent of interaction. The optimum values of stirring time, settling time, firing temperature and the strength of the acid for Cd(II) - peat interaction are 5 min, 75 min, 200 °C and 2.0 mol dm-3, respectively.
  • KUSUI Takashi, AMANO Norimasa, NOTO Yuji, TATEDA Masafumi, ITO Hajime
    2013 年 17 巻 1 号 p. 39-43
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    The questionnaire survey was conducted to investigate the actual condition of disposal & recycle of concrete sludge and those cost in Toyama Prefecture to explore the possibility of recycling. The results showed that the most popular method was disposal of dewatered and dried sludge as dewatered cake at final landfill site which accounted for around 55%. The other 7% was recycled as sludge water, and 38% was recycled as reused concrete after solidification. These recycle methods will be regarded as promising recycle methods. The production rate of sludge varied depending on disposal method, and this rate for solidification method was 0.5 % which is half of that of dewatered sludge. The unit cost of disposal was lower for solidification than that for dewatered sludge. However, some sludge showed higher concentration of Cr 6+ leaching than the environmental quality standard. The strength property of concrete was studied when the sludge was mixed as cement or fine aggregate. It is clear that the standard strength was not fulfilled with the increase of mixed ratio of sludge as a substitute for cement. The result showed that almost half of sludge produced at concrete mills in Toyama Prefecture was recycled. The recycle of sludge water will be further promoted with the care of Cr6+ concentration due to the high leaching potential of some sludge. However, the mixing ratio of sludge will not be increased too much to meet the strength criterion for paving slag, requiring for other efficient recycle methods.
  • LINDA BL Lim, NAMAL Priyantha, DTB Tennakoon, TASNEEM Zehra
    2013 年 17 巻 1 号 p. 45-49
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    This research was conducted to provide insight to the equilibrium and kinetics aspects of interaction of aqueous Cu(II) species with peat available in Brunei Darussalam. About 50% removal of Cu(II) from solution under optimized laboratory conditions at ambient pH was observed with raw peat. Acidification of peat with HNO3 solution as well as the treatment with diluted NaOH solution improve the extent of interaction resulting in a higher removal of about 70%, showing the complex nature of Cu(II) - peat interactions. Investigation of the extent of Cu(II) sorbed by raw, HNO3-treated and NaOH-treated peat as a function of equilibrium concentration indicates the agreement with the Langmuir isotherm for lower concentrations, fulfilling the requirement of the mono-layer coverage, followed by removal of more Cu(II) from the solution, which is equivalent to the multi-layer coverage, beyond the initial concentration of 200 mg L-1 Cu(II). Further, kinetics data obtained are in good agreement with the pseudo second order model with an average rate constant of 1.3 mol L-1 s-1.
  • 芹川 裕加, 渡辺 幸一, 川上 智規, 三宅 隆之
    2013 年 17 巻 1 号 p. 51-55
    発行日: 2013年
    公開日: 2015/03/11
    ジャーナル フリー
    Globally, 2/3 of the anthropogenic emission of gaseous mercury to the atmosphere is estimated to be from Asia, especially from China. Japan is located in the eastern side of the China continent, and long-range transportation of air pollutants is one of the environmental concerns. The concentrations of the atmospheric gaseous mercury, SO2, O3, and SO42- at the altitude 2450m and 977m on Mt.Tateyama, faces the Japan Sea, were measured simultaneously to detect long-range transportation of the pollutants. Gaseous mercury could be transported from China simultaneously with O3 and SO42-, however, the increase in the concentration of mercury was smaller than other components.
feedback
Top