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871.
Pan Ruming Martins Marcio Ferreira Debenest Gérald 《Journal of Material Cycles and Waste Management》2023,25(1):198-210
Journal of Material Cycles and Waste Management - This study aims to maximize the waste polypropylene (WPP) pyrolysis oil yield by regulating the operating parameters. The interactions of operating... 相似文献
872.
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874.
Distribution and bioaccumulation of organochlorine pesticides (OCPs) in food web of Nansi Lake,China 总被引:2,自引:0,他引:2
Guizhai Zhang Zhaoke Pan Aiying Bai Jing Li Xiaoming Li 《Environmental monitoring and assessment》2014,186(4):2039-2051
The concentration of 12 organochlorine pesticides (OCPs) were measured in water, sediment, aquatic plant, and animal (shrimp and fish) of Nansi Lake by gas chromatography equipped with an electron capture detector. The total OCPs concentrations were 65.31–100.31 ng L?1 in water, 2.9–6.91 ng g?1 dry weight (dw) in sediments, 1.29–6.42 ng g?1 dw in aquatic plants and 7.57–17.22 ng g?1 dw in animals. The OCPs composition profiles showed that heptachlor compounds was also the predominant OCPs contaminants in addition to hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in Nansi Lake. According to the source of HCHs and DDTs in sediment samples, there was no new input and the HCHs pollution mainly came from the use of Lindane in Nansi Lake. Bioaccumulation of OCPs in aquatic biota indicated that DDTs and heptachlor compounds had a strong accumulation, followed by HCHs and drins. The accumulation abilities of fish for OCPs were higher than those of plants and shrimps. The OCPs biota-sediment accumulation factor values of Channa argus was the highest in fish samples, followed by Carassius auratus, and Cyprinus caspio. Risk assessment of sediment showed that heptachlor epoxide had a higher occurrence possibility of adverse ecological effects to benthic species. Based on the calculation of acceptable daily intake and hazard ratio, HCHs in fish and shrimps from Nansi Lake had a lifetime cancer risk of greater than one per million. The risk assessment of water, sediment, and fish indicated the water environment of Nansi Lake is at a safe level at present. 相似文献
875.
In the Netherlands, pesticide monitoring of the surface water is separately managed by different water authorities. These
water authorities can decide when, where, and what pesticide will be monitored and at what frequency. To help make the decisions
more reasonable and make the monitoring system more efficient and systematic, three new types of monitoring maps were developed.
The maps are based on actual pesticide measurement from current monitoring system and crop data. Combined temporal and spatial
distribution maps give an overview of the pesticide problem in the whole Netherlands. It can be used to develop a strategy
in which season and where the pesticide should be intensively monitored. Temporal distribution map, together with the pesticide
usage prediction map, provide information of individual pesticide. They help to find out when and at what frequency and which
pesticide be monitored, based on which monitoring facilities can be applied more efficiently. 相似文献
876.
Yuan-Bin Cai Hao Zhang Wen-Bin Pan Yan-Hong Chen Xiang-Rong Wang 《Environmental monitoring and assessment》2013,185(6):5111-5123
This paper quantifies the allocation of ecosystem services value (ESV) associated with land use pattern and qualitatively examined impacts of land use changes and socio-economic factors on spatiotemporal variation of ESV in the Natural Wetland Distribution Area (NWDA), Fuzhou city, China. The results showed that total ESV of the study area decreased from 4,332.16?×?106 RMB Yuan in 1989 to 3,697.42?×?106 RMB Yuan in 2009, mainly due to the remarkable decreases in cropland (decreased by 55.3 %) and wetland (decreased by 74.2 %). Forest, water, and wetland played major roles in providing ecosystem services, accounting for over 90 % of the total ESV. Based on time series Landsat TM/ETM+ imagery, geographic information system, and historical data, analysis of the spatiotemporal variation of ESV from 1989 to 2009 was performed. It indicated that rapid expansion of urban areas along the Minjiang River resulted in significant changes in land use types, leading to a dramatic decline in ecosystem services. Meanwhile, because of land scarcity and unique ecosystem functions, the emergency of wetland and cropland protection in built-up area has become an urgent task of local authorities to the local government. Furthermore, there was still a significant negative correlation between ESV of cropland and wetland and the GDP. The results suggest that future planning of land use pattern should control encroachment of urban areas into cropland and wetland in addition to scientific and rational policies towards minimizing the adverse effects of urbanization. 相似文献
877.
Mercury concentration in the muscle of seven fish species from Chagan Lake,Northeast China 总被引:2,自引:0,他引:2
Chagan Lake is located downstream of the Second Songhua River basin in Northeast China. It is one of the top ten inland freshwater
lakes, and an important aquatic farm in China. The lake has been receiving large amounts (currently at 1.5 × 108 m3/a) of water from the river since 1984. This would pose a threat to the aquatic system of the lake because the river was seriously
polluted with mercury in 1970s–1980s. The current study is the first to report the total mercury concentrations in fish found
in the lake. Mercury concentrations in seven fish species collected from the lake in January 2009 were determined. The related
human health risk from fish consumption was also assessed. The average concentration of mercury in the fish was 18.8 μg/kg
of wet weight, ranging from 4.5 to 37.6 μg/kg of wet weight. A large difference in the mercury concentrations among the fish
species was found. The mercury concentration was found to be higher in carnivorous species and lower in omnivorous and herbivorous
species. This demonstrates greater mercury bioaccumulation in fish species at higher trophic levels. Mercury concentrations
in fish showed significant positive correlations with age, length, and weight. No significant relationship was found between
mercury concentrations in fish and the habitat preferences. Mercury concentrations in fish from the lake were within the limits
of the international and national standards of China established for mercury. According to the reference doses established
by the United States Environmental Protection Agency, the maximum safe consuming quantity considering all the fish was 297.3 g/day/person,
which was more than five times as much as the current quantity (50 g/day/person) consumed by the local residents. This investigation
indicates that the historical pollution of the Second Songhua River has not caused mercury bioaccumulation in fish muscle
tissue of Chagan Lake. The present consumption of fish from the lake in the local area does not pose a threat to human health. 相似文献
878.
北京市主要水污染物排放特征及水质改善对策 总被引:3,自引:1,他引:2
污染排放信息是环境决策的重要依据。分析了北京市水环境质量的现状,基于最新源排放清单,解析北京市当前主控污染物COD、氨氮排放的结构特征和空间特征,以期为北京市开展基于流域综合治理的水污染控制和水环境管理提供依据。按照工业源、农业源、生活源和集中处理设施的环境统计口径,2013年,COD、氨氮的排放构成分别为2.7%、37.1%、35.0%、25.3%和1.5%、20.1%、54.8%、23.6%。其中,农业源中畜禽养殖排放是主要来源,COD、氨氮总排放分别占农业源总排放量的94.7%和87.0%。在北京市五大水系中,北运河流域排放量最大,COD、氨氮排放量分别占全市总排放量的53.3%和57.4%。为改善北京市水环境质量,建议从加快污水处理厂提标改造、推动面源污染治理、加强水利联通、合理规划城市规模布局等4个方面入手。 相似文献
879.
北方沙尘对四川盆地环境空气质量影响和特征分析 总被引:4,自引:1,他引:3
利用沙尘天气资料和颗粒物浓度、激光雷达监测数据以及后向轨迹,分析浮尘天气的气象特征及传输路径,构建了浮尘天气对四川盆地各城市大气环境质量影响的量化指标,并利用该量化指标分析了浮尘天气对四川盆地各城市大气环境的影响,得出2013—2015年浮尘对四川盆地PM_(10)年均质量浓度的贡献,2013—2015年约为4.82、1.00、0.56μg/m~3;浮尘对PM_(10)年均质量浓度的贡献川西区域最大,川东北区域次之,川中区域最小,其贡献量分别为3.5、2.2、1.4μg/m~3。同时还进一步分析浮尘对区域PM_(10)影响差异的原因。 相似文献
880.
考虑水温变化的变降解系数在北京市北运河水质模拟中的应用 总被引:2,自引:1,他引:1
综合降解系数是水质模拟预测、水环境容量计算中的关键参数之一,并且受温度影响较大。首先基于北京市北运河代表站2010年逐日水温资料,根据描述氨氮降解系数与温度之间数量关系的经验公式,得到随水温变化的动态降解系数以及年均水温对应的恒定降解系数,并采用模型试错法进行修正。然后基于MIKE11模型,模拟了采用变降解系数和恒定降解系数2种情景下北运河榆林庄断面氨氮浓度的变化。结果表明:2种情景均能较好地模拟氨氮浓度的年变化趋势,但采用变降解系数下大多月份模拟得到的月均质量浓度相对实测值误差较小,尤其是4—12月各月平均质量浓度模拟误差控制在15%以内,全年日均质量浓度模拟误差不足4%,模型表现更为稳定。 相似文献