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Irrigation system and land use effect on surface water quality in river, at lake Dianchi, Yunnan, China 总被引:1,自引:0,他引:1
Takashi Tanak Takahiro Sato Kazuo Watanabe Ying Wang Dan Yang Hiromo Inoue Kunzhi Li Tatsuya Inamura 《环境科学学报(英文版)》2013,25(6):1107-1116
The surface water samples were collected in river Dahe and its tributaries, which flow into severely eutrophic lake Dianchi, Yunnan Province, China, in order to elucidate factors controlling water quality fluctuations. The temporal and spatial distribution of water quality tendency was observed. The water quality of each river is dependent on the hydrology effect such water gate and circulating irrigation system. We must consider the hydrology effect to accurately understand water quality variations of river in this study field. In river without highly circulating irrigation system or water gate effect, the downstream nitrate nitrogen (NO3-N) concentration increase occurred in area dominated by open field cultivation, whereas the NO3-N concentration was constant or decreased in area dominated by greenhouse land use. This result suggests that greenhouse covers the soil from precipitation, and nitrate load of greenhouse could be less than that of open field cultivation while the rainfall event. In the upper reaches of river, where is dominated by open field cultivation, there were no sharp increase dissolved molybdate reactive phosphorus and total phosphorus concentration, but P load was accumulated in the lower reaches of river, whose predominant land use is greenhouse. Although the P sources is unclear in this study, greenhouse area may have potential of P loads due to its high P content in greenhouse soil. Considering hydrology effect is necessary to determine what the major factor is influencing the water quality variation, especially in area with highly complicated irrigation system in this studying site. 相似文献
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The vast majority of ectothermic organisms grow larger when developing at cooler environmental temperatures, a pattern frequently referred to as the temperature-size rule (TSR). Assuming that this reaction norm has adaptive significance, life history theory predicts that converse patterns may evolve if favored by natural selection, namely if the costs associated with complying to the TSR outweigh the benefits. Calcifying ectotherms may comprise such an exception not following the TSR, because calcification is expected to be more costly at lower temperatures thus increasing associated costs. To test this hypothesis, we reared wild-caught juveniles of the intertidal gastropod Monetaria annulus and compared their shell sizes at the end of the juvenile stage between two rearing temperatures. Contrary to our prediction, M. annulus does follow the TSR, suggesting that increased calcification costs at lower temperatures are not high enough to break the TSR. Such plastic responses should be considered when interpreting geographical patterns such as latitudinal size clines, which may be caused at least partly by phenotypic plasticity. 相似文献
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Masanobu Mori Tsuyoshi Sugita Akinori Mase Takahiro Funatogawa Masaru Kikuchi Kazuhiko Aizawa Shigekazu Kato Yoichi Saito Tsukasa Ito Hideyuki Itabashi 《Chemosphere》2013,90(4):1359-1365
This paper reports on the photodecomposition of aqueous humic acid (HA) by a TiO2-coated ceramic foam filter (TCF) reactor and on the potential for the formation of disinfection byproducts (DBPs) upon chlorination of the photocatalytically treated solutions. This photocatalytic reactor can also be applied to the removal of natural organic matter (NOM) in swamp waters. The proposed photocatalytic reaction system was operated as per standardized methodologies. First, the ability of the TCF to decompose HA (a representative compound of NOM) was evaluated from the changes in the total organic carbon (TOC) and UV254 with the reaction time. Remarkably, TOC removal and UV254 values ranging from 44% to 61% and from 60% to 83%, respectively, were achieved. The potential for the formation of DBPs (total trihalomethane and total haloacetic acid) by chlorination of the phototreated solution was strongly dependent on the TOC removal and UV254 values in the solution. The degree of photodecomposition of NOMs in the swamp water samples and the DBP formation potential showed similar trends as in the case of the standard solutions containing HA. The method used in this study could be effectively used to evaluate the efficiency of TCF for reducing HA and NOM, while suppressing the formation of DBP products. 相似文献
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Kosuke Toshiki Pham Quy Giang Kevin Roy B. Serron Takahiro Sekikaw Jeoung-soo Yu Baasandash Choijil Shoichi Kunikane 《环境科学学报(英文版)》2015
Currently, most developing countries have not set up municipal solid waste management systemswith a viewof recovering energy fromwaste or reducing greenhouse gasemissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production, incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently, 3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sortingmay be considered as the second step of energy recovery. However, safety control and marketability of RDF will be required at that moment. 相似文献
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Miyuki Nishiyama Akihiko Sekizawa Kohei Ogawa Hideaki Sawai Hiroaki Nakamura Osamu Samura Nobuhiro Suzumori Setsuko Nakayama Takahiro Yamada Masaki Ogawa Yukiko Katagiri Jun Murotsuki Yoko Okamoto Akira Namba Haruka Hamanoue Masanobu Ogawa Kiyonori Miura Shunichiro Izumi Yoshimasa Kamei Haruhiko Sago 《黑龙江环境通报》2016,36(12):1121-1126
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Fungus-growing ants (Attini) live in an obligate mutualism with the fungi they cultivate for food. Because of the obligate nature of this relationship, the success of the ants is directly dependent on their ability to grow healthy fungus gardens. Attine ants have evolved complex disease management strategies to reduce their gardens exposure to potential parasitic microbes, to prevent the establishment of infection in their gardens, and to remove infected garden sections. The infrabuccal pocket, a filtering device located in the oral cavity of all ants, is an integral part of the mechanisms that leaf-cutter ants use to prevent the invasion and spread of general microbial parasites and the specific fungal-garden parasite Escovopsis. Fungus-growing ants carefully groom their garden, collecting general debris and pathogenic spores of Escovopsis in their infrabuccal pocket, the contents of which are later expelled in dump chambers inside the nest or externally. In this study we examined how a phylogenetically diverse collection of attine ants treat their infrabuccal pellets. Unlike leaf-cutters that deposit their infrabuccal pellets directly in refuse piles, ants of the more basal attine lineages stack their infrabuccal pellets in piles located close to their gardens, and a separate caste of workers is devoted to the construction, management, and eventual disposal of these piles. 相似文献
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In vivo exposure of rats to 10 ppm nitrogen dioxide (NO2) for 12h caused changes in fatty acids composition of alveolar lavage phospholipids. Among the fatty acid species, the relative ratio of palmitic acid, myristic acid and palmitoleic acid increased significantly. While the relative ratio of stearic acid, oleic acid, linoleic acid and arachidonic acid decreased significantly. Both the increase in the incorporation of palmitic acid in phosphatidylcholine which would be released into the alveoli and the increase in the release of phosphatidylcholine into the alveoli may account for the changes in the fatty acid composition of the present findings. 相似文献