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Paudyal Hari Inoue Katsutoshi Kawakita Hidetaka Ohto Keisuke Kamata Hirofumi Alam Shafiq 《Journal of Material Cycles and Waste Management》2018,20(2):975-984
Journal of Material Cycles and Waste Management - Spent strongly acidic cation exchange resin was effectively used for the removal of trace concentration of fluoride ions. For this purpose, the... 相似文献
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Ionic composition of wet precipitation over the southern slope of central Himalayas,Nepal 总被引:1,自引:0,他引:1
Lekhendra Tripathee Shichang Kang Jie Huang Mika Sillanpää Chhatra Mani Sharma Zoe Lucia Lüthi Junming Guo Rukumesh Paudyal 《Environmental science and pollution research international》2014,21(4):2677-2687
Severe atmospheric pollution transported to Himalayas from South Asia may affect fragile ecosystem and can be harmful for human health in the region. In order to understand the atmospheric chemistry in the southern slope of central Himalayas, where the data is limited, precipitation has been sampled at four sites: Kathmandu (1,314 m), Dhunche (2,065 m), Dimsa (3,078 m), and Gosainkunda (4,417 m) in Nepal for over a 1-year period characterized by an urban, rural, and remote sites, respectively. HCO3 ? is the dominant anion, while the NH4 + is the dominant cation in precipitation at the four sites. Generally, most of ions (e.g., SO4 2?, NO3 ?, NH4 +, HCO3 ?, and Ca2+) have higher concentrations in urban site compared to the rural sites. Neutralization factor calculation showed that precipitation in the region is highly neutralized by NH4 + and Ca2+. Empirical orthogonal function and correlation analysis indicated that the precipitation chemistry was mostly influenced by crustal, anthropogenic, and marine sources in Nepal. Among different sites, urban area was mostly influenced by anthropogenic inputs and crustal dusts, whereas remote sites were mostly from marine and crustal sources. Seasonal variations show higher ionic concentrations during non-monsoon seasons mainly due to limited precipitation amount. On the other hand, lower ionic concentrations were observed during monsoon season when higher amount of precipitation washes out aerosols. Thus, precipitation chemistry from this work can provide a useful database to evaluate atmospheric environment and its impacts on ecosystem in the southern slope of central Himalayas, Nepal. 相似文献
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Paudyal Rukumesh Kang Shichang Guo Junming Tripathee Lekhendra Sharma Chhatra Mani Huang Jie Li Yang Yan Fangping Wang Kun Chen Jizu Qin Xiang Sillanpaa Mika 《Environmental science and pollution research international》2021,28(37):51530-51543
Environmental Science and Pollution Research - In this work, samples of surface snow, surface ice, snow pit and meltwater from the Laohugou Glacier No. 12 on the northern edge of Tibetan Plateau... 相似文献
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Paudyal Hari Pangeni Bimala Inoue Katsutoshi Ohto Keisuke Kawakita Hidetaka 《Journal of Material Cycles and Waste Management》2022,24(6):2510-2526
Journal of Material Cycles and Waste Management - An efficient and environmentally benign biosorbent for Mo(VI) and W(VI) sequestration was developed by loading Zr(IV) ions onto Saponified Orange... 相似文献
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Shiwei Sun Shichang Kang Junming Guo Qianggong Zhang Rukumesh Paudyal Xuejun Sun Dahe Qin 《环境科学学报(英文版)》2018,30(6):130-142
The Tibetan Plateau(TP) is recognized as "Water Tower of Asia". Yet our understanding of mechanisms influencing incorporation of mercury(Hg) into freshwater in mountain glaciers on the TP remains quite limited. Extensive sampling of environmental matrices(e.g., snow/ice)were conducted on the East Rongbuk glacier on Mt. Everest and Zhadang glacier on Mt.Nyainqentanglha for Hg speciation analysis. Speciated Hg behaved quite different during snowmelt: a preferential early release of DHg(dissolved Hg) was observed at the onset of snowmelt, whereas PHg(particulate-bound Hg) and THg(total Hg) become relatively enriched in snow and released later. Small fraction of Hg in snow was lost during a snowmelt day(18.9%–34.7%) with a large proportion(58.1%–87.3%) contributed by PHg decrease, indicating that the deposited Hg is most likely retained in glacier snow/ice. Furthermore, THg were positively correlated with PHg and crustal major ions(e.g., Ca~(2+), Mg~(2+)) during snowmelt, indicating that Hg is mainly migrated with particulates. The main pathway of Hg loss during snowmelt was most probably associated with release of PHg with meltwater, which was greatly influenced by ablation intensity of snow/ice. This should be paid particular concern as Hg preserved in mountain glaciers will mostly enter aquatic ecosystem as climate warms, impacting on downstream ecosystems adversely. Obvious decrease of THg during the downstream transport from glacier was observed with a large proportion contributed by PHg decrease. The main removal mechanism of Hg was associated with sedimentation of PHg during the transport process. 相似文献
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