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1.
Junming Guo Shichang Kang Jie Huang Mika Sillanpää Hewen Niu Xuejun Sun Yuanqing He Shijing Wang Lekhendra Tripathee 《环境科学学报(英文版)》2017,29(2):18-28
In order to investigate the compositions and wet deposition fluxes of trace elements and rare earth elements (REEs) in the precipitation of the southeastern edge of the Tibetan Plateau, 38 precipitation samples were collected from March to August in 2012 in an urban site of Lijiang city in the Mt. Yulong region. The concentrations of most trace elements and REEs were higher during the non-monsoon season than during the monsoon season, indicating that the lower concentrations of trace elements and REEs observed during monsoon had been influenced by the dilution effect of increased precipitation. The concentrations of trace elements in the precipitation of Lijiang city were slightly higher than those observed in remote sites of the Tibetan Plateau but much lower than those observed in the metropolises of China, indicating that the atmospheric environment of Lijiang city was less influenced by anthropogenic emissions, and, as a consequence, the air quality was still relatively good. However, the results of enrichment factor and principal component analysis revealed that some anthropogenic activities (e.g., the increasing traffic emissions from the rapid development of tourism) were most likely important contributors to trace elements, while the regional/local crustal sources rather than anthropogenic activities were the predominant contributors to the REEs in the wet deposition of Lijiang city. Our study was relevant not only for assessing the current status of the atmospheric environment in the Mt. Yulong region, but also for specific management actions to be implemented for the control of atmospheric inputs and the health of the environment for the future. 相似文献
2.
Tripathee Lekhendra Kang Shichang Rupakheti Dipesh Cong Zhiyuan Zhang Qianggong Huang Jie 《Environmental science and pollution research international》2017,24(31):24454-24472
Environmental Science and Pollution Research - In order to investigate the spatial and temporal variations of aerosols and its soluble chemical compositions of the data gap zone in the central... 相似文献
3.
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
4.
Linda Maharjan Shichang Kang Lekhendra Tripathee Chaman Gul Huijun Zheng Quanlian Li Pengfei Chen Mukesh Rai Ewerton Santos 《环境科学学报(英文版)》2022,34(2):1-15
Much attention is drawn to polycyclic aromatic hydrocarbons(PAHs) as an air pollutant due to their toxic, mutagenic and carcinogenic properties. Therefore, to understand the levels, seasonality, sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan, total suspended particle(TSP) samples were collected for over one year period. The average total PAH concentrations were 31.5 ± 24.4 and 199 ± 229 ng/m3 in Karachi and Mardan, re... 相似文献
5.
Distribution and transportation of mercury from glacier to lake in the Qiangyong Glacier Basin, southern Tibetan Plateau, China 总被引:1,自引:0,他引:1
Shiwei Sun Shichang Kang Jie Huang Chengding Li Junming Guo Qianggong Zhang Xuejun Sun Lekhendra Tripathee 《环境科学学报(英文版)》2016,28(6):213-223
The Tibetan Plateau is home to the largest aggregate of glaciers outside the Polar Regions and is a source of fresh water to 1.4 billion people. Yet little is known about the transportation and cycling of Hg in high-elevation glacier basins on Tibetan Plateau. In this study, surface snow,glacier melting stream water and lake water samples were collected from the Qiangyong Glacier Basin. The spatiotemporal distribution and transportation of Hg from glacier to lake were investigated. Significant diurnal variations of dissolved Hg(DHg) concentrations were observed in the river water, with low concentrations in the morning(8:00 am–14:00 pm) and high concentrations in the afternoon(16:00 pm–20:00 pm). The DHg concentrations were exponentially correlated with runoff, which indicated that runoff was the dominant factor affecting DHg concentrations in the river water. Moreover, significant decreases of Hg were observed during transportation from glacier to lake. DHg adsorption onto particulates followed by the sedimentation of particulate-bound Hg(PHg) could be possible as an important Hg removal mechanism during the transportation process. Significant decreases in Hg concentrations were observed downstream of Xiao Qiangyong Lake, which indicated that the high-elevation lake system could significantly affect the distribution and transportation of Hg in the Qiangyong Glacier Basin. 相似文献
6.
Hemraj Bhattarai Lekhendra Tripathee Shichang Kang Chhatra Mani Sharm Pengfei Chen Junming Guo Prakriti Sharma Ghimire 《环境科学学报(英文版)》2021,33(4):37-52
Precipitation represents an important phenomenon for carbon and nitrogen deposition. Here, the concentrations and fluxes of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) with their potential sources were analyzed in wet precipitation during summer monsoon from the Northern Indo-Gangetic Plain (IGP), important but neglected area. The volume-weighted mean (VWM) concentration of DOC and TDN were 687.04 and 1210.23 µg/L, respectively. Similarly, the VWM concentration of major ions were in a sequence of NH4+ > Ca2+ > SO42- > Na+ > K+ > NO3? > Cl? > Mg2+ > F? > NO2?, suggesting NH4+ and Ca2+ from agricultural activities and crustal dust played a vital role in precipitation chemistry. Moreover, the wet deposition flux of DOC and TDN were 9.95 and 17.06 kg/(ha?year), respectively. The wet deposition flux of inorganic nitrogen species such as NH4+-N and NO3?-N were 14.31 and 0.47 kg/(ha?year), respectively, demonstrating the strong influence of emission sources and precipitation volume. Source attribution from different analysis suggested the influence of biomass burning on DOC and anthropogenic activities (agriculture, animal husbandry) on nitrogenous species. The air-mass back trajectory analysis indicated the influence of air masses originating from the Bay of Bengal, which possibly carried marine and anthropogenic pollutants along with the biomass burning emissions to the sampling site. This study bridges the data gap in the less studied part of the northern IGP region and provides new information for policy makers to deal with pollution control. 相似文献
7.
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
8.
Hemraj Bhattarai Lekhendra Tripathee Shichang Kang Pengfei Chen Chhatra Mani Sharm Kirpa Ram Junming Guo Maheswar Rupakheti 《环境科学学报(英文版)》2022,34(5):10-24
This study reports for the first time a comprehensive analysis of nitrogenous and carbonaceous aerosols in simultaneously collected PM2.5 and TSP during pre-monsoon (March–May 2018) from a highly polluted urban Kathmandu Valley (KV) of the Himalayan foothills. The mean mass concentration of PM2.5 (129.8 µg/m3) was only ~25% of TSP mass (558.7 µg/ m3) indicating the dominance of coarser mode aerosols. However, the mean concentration as well as fractional contributions of water-soluble total nitrogen (WSTN) and carbonaceous species reveal their predominance in find-mode aerosols. The mean mass concentration of WSTN was 17.43±4.70 µg/m3 (14%) in PM2.5 and 24.64±8.07 µg/m3 (5%) in TSP. Moreover, the fractional contribution of total carbonaceous aerosols (TCA) is much higher in PM2.5 (~34%) than that in TSP (~20%). The relatively low OC/EC ratio in PM2.5 (3.03 ± 1.47) and TSP (4.64 ± 1.73) suggests fossil fuel combustion as the major sources of carbonaceous aerosols with contributions from secondary organic aerosols. Five-day air mass back trajectories simulated with the HYSPLIT model, together with MODIS fire counts indicate the influence of local emissions as well as transported pollutants from the Indo-Gangetic Plain region to the south of the Himalayan foothills. Principal component analysis (PCA) also suggests a mixed contribution from other local anthropogenic, biomass burning, and crustal sources. Our results highlight that it is necessary to control local emissions as well as regional transport while designing mitigation measures to reduce the KV's air pollution. 相似文献
9.
Seasonality of carbonaceous aerosol composition and light absorption properties in Karachi, Pakistan
Pengfei Chen Shichang Kang Chaman Gul Lekhendra Tripathee Xiaoxiang Wang Zhaofu Hu Chaoliu Li Tao Pu 《环境科学学报(英文版)》2020,32(4):286-296
Characteristics of carbonaceous aerosol(CA) and its light absorption properties are limited in Karachi,which is one of the most polluted metropolitan cities in South Asia.This study presents a comprehensive measurement of seasonality of CA compositions and mass absorption cross-section(MAC) of elemental carbon(EC) and water-soluble organic carbon(WSOC) in total suspended particles(TSP) collected from February 2015 to March 2017 in the southwest part of Karachi.The average TSP,organic carbon(OC),and EC concentrations were extremely high with values as 391.0±217.0,37.2±28.0,and 8.53±6.97 μg/m~3,respectively.These components showed clear seasonal variations with high concentrations occurring during fall and winter followed by spring and summer.SO_4~(2-),NO_3~-,K~+,and NH_4~+showed similar variations with CA,implying the significant influence on atmospheric pollutants from anthropogenic activities.Relatively lower OC/EG ratio(4.20±2.50)compared with remote regions further indicates fossil fuel combustion as a primary source of CA.Meanwhile,sea salt and soil dust are important contribution sources for TSP.The average MAC of EC(632 nm) and WSOC(365 nm) were 6.56±2.70 and 0.97±0.37 m~2/g,respectively.MAC_(EC) is comparable to that in urban areas but lower than that in remote regions,indicating the significant influence of local emissions.MACwsoc showed opposite distribution with EC,further suggesting that OC was significantly affected by local fossil fuel combustion.In addition,dust might be an important factor increasing MACwsoc particularly during spring and summer. 相似文献
10.
Chen Pengfei Kang Shichang Tripathee Lekhendra Panday Arnico K. Rupakheti Maheswar Rupakheti Dipesh Zhang Qianggong Guo Junming Li Chaoliu Pu Tao 《Environmental science and pollution research international》2020,27(10):10617-10628
Environmental Science and Pollution Research - Total suspended particles (TSP) were collected in Lumbini from April 2013 to March 2016 to better understand the characteristics of carbonaceous... 相似文献