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Assessment of fire emission inventories for simulating particulate matter in Upper Southeast Asia using WRF-CMAQ Полный текст
2017
Vongruang, Patipat | Wongwises, Prungchan | Pimonsree, Sittichai
Biomass burning is a major source of particulate matter pollution in Upper Southeast Asia (U-SEA), and accurate fire emissions estimates are of great importance in predicting air quality. In this work, we assess two global fire emission inventories, the Fire INventory from NCAR (FINN) and the Global Fire Assimilation System (GFAS), using the WRF-CMAQ modeling system to simulate aerosol in U-SEA. Simulated particulate matter is compared to observational data from satellites and ground measurements. This study investigates a biomass burning episode that occurred in March 2012. Both emission inventories show similar temporal and spatial variations in PM; however, the quantities of total PM10 emissions differ greatly between FINN and GFAS, with an approximate fivefold ratio of FINN/GFAS. In the source region, simulated PM10 using FINN (PM10FINN) is greatly overestimated, whereas simulated PM10 using GFAS (PM10GFAS) is considerably underestimated. The monthly PM10 averages of PM10FINN, PM10GFAS and observed PM10 in Northern Thailand are 312, 79 and 143 μg/m3, respectively. This study found considerable uncertainties in both FINN and GFAS emission inventories in U-SEA, and these uncertainties were analyzed in this paper. Fire emission estimations require improved specific calculation parameters (i.e. burned area and fuel loading factor for FINN, conversion factor to estimate dry matter burned from fire radiative power for GFAS, emission factors and plume height) to accurately estimate biomass burning emissions for the U-SEA region.
Показать больше [+] Меньше [-]Seasonal variation, flux estimation, and source analysis of dissolved emerging organic contaminants in the Yangtze Estuary, China Полный текст
2017
Zhao, Heng | Cao, Zhen | Liu, Xue | Zhan, Yi | Zhang, Jing | Xiao, Xi | Yang, Yi | Zhou, Junliang | Xu, Jiang
The occurrence and seasonal variation of 24 dissolved emerging organic contaminants in the Yangtze Estuary were studied, including 12 non-antibiotic pharmaceuticals, seven sulfonamides, two macrolides and three chloramphenicols. Sulfadiazine, erythromycin, thiamphenicol and paracetamol were the primary contaminants in sulfonamides, macrolides, chloramphenicols and non-antibiotic pharmaceutical groups, respectively. Compared to the concentrations at Datong, chloramphenicols at Xuliujing were significantly higher in autumn and winter, while macrolides were lower in spring. Based on the flux estimation, approximately 37.1 tons of sulfonamides, 17.4 tons of macrolides, 79.2 tons of chloramphenicols and 14.1 tons of non-antibiotic pharmaceuticals were discharged into the Yangtze Estuary from June 2013 to May 2014. However, the total flux from the Huangpu River only represented 5% of the total. The pharmaceutical sources were speculated on by analyzing the seasonal variations in pharmaceutical concentrations and fluxes at various sites. Both environmental and social factors might affect the fluxes.
Показать больше [+] Меньше [-]The role of citizen science in monitoring small-scale pollution events Полный текст
2017
Hyder, Kieran | Wright, Serena | Kirby, Mark | Brant, Jan
Small-scale pollution events involve the release of potentially harmful substances into the marine environment. These events can affect all levels of the ecosystem, with damage to both fauna and flora. Numerous reporting structures are currently available to document spills, however there is a lack of information on small-scale events due to their magnitude and patchy distribution. To this end, volunteers may provide a useful tool in filling this data gap, especially for coastal environments with a high usage by members of the public. The potential for citizen scientists to record small-scale pollution events is explored using the UK as an example, with a focus on highlighting methods and issues associated with using this data source. An integrated monitoring system is proposed which combines citizen science and traditional reporting approaches.
Показать больше [+] Меньше [-]Spatial assessment of radiocaesium in the largest lagoon in Fukushima after the TEPCO Fukushima Dai-ichi Nuclear Power Station accident Полный текст
2017
Kambayashi, Shota | Zhang, Jing | Narita, Hisashi
Radionuclides deposited on land by global fallouts and nuclear power station accidents spread over coastal environments through estuarine areas connecting land to ocean. In this study, we monitored activity concentration of radiocaesium in surface sediment and re-suspended particles in Matsukawa-ura lagoon, the largest lagoon in Fukushima, after the TEPCO Fukushima Dai-ichi Nuclear Power Station accident. Radiocaesium distribution in surface sediment varied spatiotemporally and irregularly due to the effect of tidal waves. The effective half-life was significantly shorter than physical half-life, suggesting some system of radiocaesium discharge in the lagoon. Sediment trap observation revealed re-suspended particles from sediment were transported to the ocean. For these reasons, it is suggested that re-suspension of particles in the lagoon and their transportation to the ocean by the seawater exchange process are important processes of radiocaesium discharge. Moreover, our results show that seawater exchange process contributes to the dispersion of radiocaesium in the ocean.
Показать больше [+] Меньше [-]Source apportionment of PM2.5 pollution in an industrial city in southern China Полный текст
2017
Zou, Bei-Bing | Huang, Xiao Feng | Dai, Jing | Zhang, Bin | Zeng, Li-Wu | Feng, Ning | He, Ling-Yan
Severe PM2.5 pollution has become a great challenge to atmospheric pollution control in China. Most of previous aerosol source apportionment studies in China focused only on part of PM2.5 (e.g., organic matter in composition or PM1 in size) or lacked source contributions identified with necessary tempo-spatial variations, which makes the results not convincible enough for policy making. In this study, five various sites were selected for simultaneous PM2.5 observation in an industrial city in the Pearl River Delta (PRD) of South China during all four seasons of 2014. A positive matrix factorization (PMF) model was applied to the datasets of measured chemical species to perform source apportionment with the results as: (1) The annual mean PM2.5 concentration was 52.6 μg/m³, with secondary sulfate, vehicle emissions, secondary organic aerosol (SOA), and secondary nitrate identified as the major sources, contributing 24.6%, 14.5%, 12.0%, and 10.9% to PM2.5, respectively. Ship emissions, fugitive dust, biomass combustion, industrial emissions, and aged sea salt each contributed 3%–8%. (2) The tempo-spatial variations of sources reveal that secondary sulfate, SOA, biomass combustion, and ship emissions had obvious regional pollution characteristics; however, vehicle emissions, secondary nitrate, fugitive dust, and industrial emissions showed obvious local emission characteristics. (3) The exceeding standard polluted days (PM2.5>75 μg/m³) appeared with secondary nitrate, biomass burning, and SOA increasing mostly in concentration, which should be controlled more strictly. This study highlights the importance of SOA in PM2.5 pollution in China, which has been scarcely quantified for bulk PM2.5 in the literature.
Показать больше [+] Меньше [-]The impact of two oil spill events on the water quality along coastal area of Kenting National Park, southern Taiwan Полный текст
2017
Chen, Chung-Chi | Tew, Kwee Siong | Ho, Ping-Ho | Ko, Fung-Chi | Hsieh, Hung-Yen | Meng, Pei-Jie
In 2009, the container ship Colombo Queen and the oil tanker W-O BUDMO grounded off Jialeshui and Houwan, respectively, in southern Taiwan. Water quality was monitored at each site to evaluate the environmental impact caused by the resulting oil spills. The results show that the PAHs, turbidity, and other nutrients increased shortly after oil spill, however levels of these parameters eventually returned to baseline levels. On the other hand, DO saturation, pH and chl. a decreased initially, reached maxima after 10days, and returned to the baseline levels after 14days. The chl. a concentration, pH and DO saturation fluctuated in a similar pattern at both sites during the oil spills, likely driven by algal blooms. In this study, we documented a full environmental recovery at coastal areas before, during and after the oil spills.
Показать больше [+] Меньше [-]Assessment of metal concentrations (Cu, Zn, and Pb) in seawater, sediment and biota samples in the coastal area of Eastern Black Sea, Turkey Полный текст
2017
Baltas, Hasan | Sirin, Murat | Dalgic, Goktug | Bayrak, Esra Yilmaz | Akdeniz, Aysel
This study investigated the contents of Cu, Zn and Pb in seawater, sediment, different shell sizes of mussel (Mytilus galloprovincialis) and sea snail (Rapana venosa) samples collected from four different provinces of the Eastern Black Sea Region. With the exception of Zn, all the metal concentration values measured in the sea snail were observed to be higher than those of mussels in all stations. While the correlation between mussels and sea snail according to metal concentrations was found to be positive (p˂0.05), this relation was not observed between the other parameters, such as the shell sizes, salinity and pH (p˃0.05). Although the mean concentration values of Cu, Zn, and Pb for mussel and sea snail are significantly above the tolerable levels, the estimated daily intake values for mussel were below the daily intake recommended.
Показать больше [+] Меньше [-]Assessment of the benthic macrofauna in an artificial shell reef zone in Shuangdao Bay, Yellow Sea Полный текст
2017
Liu, Guoshan | Li, Wen-Tao | Zhang, Xiumei
The effects of artificial shell reef (ASR) on the benthic macroinvertebrates were studied in Shuangdao Bay, Yellow Sea, China. Results showed that the biomass of macroinvertebrates in the ASR increased with the age of the ASR. Based on self-organizing map (SOM), the macroinvertebrate community of short-term artificial reef (SAR), medium-term artificial reef (MAR) and long-term artificial reef (LAR) emerged as a cluster, which may indicate that the benthic community in the ASR formed after three years. The age of the ASR was the main factor affecting the benthic community. The macroinvertebrates belonged to six phyla, Platyhelminthes, Nemertea, Annelida, Mollusca, Arthropoda and Echinodermata, among which the latter four were the ones that contributed the most for abundance. The biomass of Mollusca increased dramatically with age. The dissimilarity of the species composition of Mollusca was mainly caused by Meretrix meretrix and Protothaca jedoensis. The two species accounted for 15.61%, 28.05% and 75.11% of the macroinvertebrate biomass found in SAR, MAR and LAR, respectively. The ASR might be served as a bivalve stock enhancement tool. We conclude that ASR could assemble macrobenthos effectively and increase the environmental quality of the adjacent area, being a valid option for marine habitat restoration purposes.
Показать больше [+] Меньше [-]Polymer/reduced graphene oxide functionalized sponges as superabsorbents for oil removal and recovery Полный текст
2017
Periasamy, Arun Prakash | Wu, Wen-Ping | Ravindranath, Rini | Roy, Prathik | Lin, Guan-Lin | Zhang, Huanzong
Polyurethane dish-washing (PU-DW) sponges are functionalized sequentially with polyethylenimine (PEI) and graphene oxide (GO) to form PEI/reduced graphene oxide (RGO) PU-DW sponges. The PEI/RGO PU-DW sponge consists of PEI/RGO sheets having numerous pores, with diameters ranging from 236 to 254nm. To further enhance hydrophobicity and absorption capacity of oil, PEI/RGO PU-DW sponge is further coated with 20% phenyltrimethoxysilane (PTMOS). The PTMOS/PEI/RGO PU-DW sponge absorbs various oils within 20s, with maximum absorption capacity values of 880% and 840% for bicycle chain oil and motorcycle engine oil, respectively. The absorbed oils were released completely by squeezing or immersed in hexane. The PTMOS/PEI/RGO PU-DW sponge efficiently separates oil/water mixtures through a flowing system. Having the advantages of faster absorption rate, reusability, and low cost, the PTMOS/PEI/RGO PU-DW sponge holds great potential as a superabsorbent for efficient removal and recovery of oil spills as well as for the separation of oil/water mixtures.
Показать больше [+] Меньше [-]Understanding how physical-biological coupling influences harmful algal blooms, low oxygen and fish kills in the Sea of Oman and the Western Arabian Sea Полный текст
2017
Harrison, Paul J. | Piontkovski, Sergey | Al-Hashmi, Khalid
In the last decade, green Noctiluca scintillans with its symbiont and other dinoflagellates such as Cochlodinium polykrikoides, Prorocentrum micans and Scrippsiella trochoidea have become the dominant HABs, partially replacing the previously dominant diatoms and red Noctiluca scintillans, especially during the northeast monsoon. Fish kills in the Sea of Oman are linked to a slow seasonal decline in oxygen concentration from January to November, probably due to the decomposition of a series of algal blooms and the deep, low oxygen waters periodically impinging the Omani shelf. In the western Arabian Sea, cyclonic eddies upwell low oxygen, nutrient-rich water and the subsequent algal bloom decays and lowers the oxygen further and leads to fish kills. Warming of the surface waters by 1.2°C over the last 5 decades has increased stratification and resulted in a shoaling of the oxycline. This has increased the probability and frequency of upwelling low oxygen water and subsequent fish kills.
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