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201.
Stormwater runoff quality from different surfaces in an urban catchment in Beijing, China 总被引:3,自引:0,他引:3
Ren Yufen Wang Xiaoke Ouyang Zhiyun Zheng Hua Duan Xiaonan Miao Hong 《Water environment research》2008,80(8):719-724
Urban stormwater runoff quality, widely investigated around the world, has been monitored less in Beijing, China, which impedes the municipal government to use best management practices to protect surface water. In this study, rainwater and stormwater runoff samples from roofs, roads, and a lawn on the campus of the Research Center for Eco-Environmental Sciences (RCEES) (Beijing, China) and from a ring road, with heavy traffic, have been sampled and analyzed for 31 storm events from June 2004 to August 2005. Total suspended solids (TSS), chemical oxygen demand (COD), 5-day biochemical oxygen demand (BOD5), total nitrogen, and total phosphorus concentrations in rainwater and runoff ranged over 2 or more orders of magnitude, meaning that the highest concentration of a certain pollutant did not always occur in a certain kind of runoff. Runoff contained significantly higher concentrations of pollutants than rainwater. On the campus of RCEES, TSS and total phosphorus in runoff samples from the lawn and roads were significantly higher than those from roofs, while the COD, BOD5, and total nitrogen concentrations were not significantly different in runoff among surfaces. Compared with runoff from the roads on campus, runoff from the ring road contained more COD and total nitrogen, but less TSS, BOD5, and total phosphorus. All pollutants measured in runoff from roofs on campus and from the ring road showed a peak concentration in starting runoff, which then decreased sharply. The peak concentrations of COD, BOD5, total nitrogen, and total phosphorus in the roof runoff increased with the increase in time of the antecedent dry period. Thus, urban stormwater pollution control, especially for first-flush control, is of great importance for the full use of rainwater and prevention of water pollution. 相似文献
202.
长江下游氮、磷含量变化及其输送量的估计 总被引:69,自引:10,他引:59
根据在1997和1998年内对长江干流大通站河水的3次采样分析,结合该站1962~1990年的水质资料,对长江下游N、P含量变化及其输送量进行研究.总氮、总磷的平均含量分别为1.6~2.2m g·L-1和0.11~0.15m g·L-1,N 以NO-3 -N 为主,约占76% ,其余主要为溶解有机氮和颗粒氮;P以颗粒态为主,占95% 以上.从5、6月到8月,NO-3-N含量是逐渐降低的,DON含量有较大幅度的上升,PN、PP及TP含量也有所增高.与历史资料相比,长江大通站溶解无机氮(DIN)和PO3-4-P含量还在不断上升,N、P含量的上升与流域化肥施用量变化趋势一致.1998年夏季洪水期间,约有79.95万tN和8.36万tP从大通站向下游输送,其中DIN与生物有效磷(BAP)比值远高于浮游植物生长的P限制值. 相似文献
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205.
Qiaohong Sun Dongxian Kong Chiyuan Miao Qingyun Duan Tiantian Yang Aizhong Ye Zhenhua Di Wei Gong 《Environmental monitoring and assessment》2014,186(9):5663-5679
Climate change has impacts on both natural and human systems. Accurate information regarding variations in precipitation and temperature is essential for identifying and understanding these potential impacts. This research applied Mann–Kendall, rescaled range analysis and wave transform methods to analyze the trends and periodic properties of global and regional surface air temperature (SAT) and precipitation (PR) over the period of 1948 to 2010. The results show that 65.34 % of the area studied exhibits significant warming trends (p?<?0.05) while only 3.18 % of the area exhibits significant cooling trends. The greatest warming trends are observed in Antarctica (0.32 °C per decade) and Middle Africa (0.21 °C per decade). Notably, 62.26 % of the area became wetter, while 22.01 % of the area shows drying trends. Northern Europe shows the largest precipitation increase, 12.49 mm per decade. Western Africa shows the fastest drying, ?21.05 mm per decade. The rescaled range analysis reveals large areas that show persistent warming trends; this behavior in SAT is more obvious than that in PR. Wave transform results show that a 1-year period of SAT variation dominates in all regions, while inconsistent 0.5-year bands are observed in East Asia, Middle Africa, and Southeast Asia. In PR, significant power in the wavelet power spectrum at a 1-year period was observed in 17 regions, i.e., in all regions studied except Western Europe, where precipitation is instead characterized by 0.5-year and 0.25-year periods. Overall, the variations in SAT and PR can be consistent with the combined impacts of natural and anthropogenic factors, such as atmospheric concentrations of greenhouse gases, the internal variability of climate system, and volcanic eruptions. 相似文献
206.
Zhengqing Cai Xiao Zhao Jun Duan Dongye Zhao Zhi Dang Zhang Lin 《Frontiers of Environmental Science & Engineering》2020,14(5):84
207.
Yanqing Duan Aijuan Zhou Xiuping Yue Zhichun Zhang Yanjuan Gao Yanhong Luo Xiao Zhang 《Frontiers of Environmental Science & Engineering》2021,15(1):12
208.
Guo Rui Jiang Sijing Hu Ming Zhan Yuhang Cheng Kun Duan Gaigai 《Environmental science and pollution research international》2021,28(24):30898-30907
Environmental Science and Pollution Research - The presence of volatile benzene series compounds (VBSCs) in the environment is continually increasing, with the potential for negative effects on... 相似文献
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选取电脑电路板上三种典型电子元器件(并行通信口、插槽、电路板)中的废塑料,研究不同的升温速率和成分对样品热解的特性影响及其动力学分析。在氮气气氛下进行热解实验,温度从室温升到1000℃,升温速率分别设为10,20℃/min。研究结果表明,并行通信口、插槽和电路板中塑料的失重有相似的变化趋势,且随着升温速率的变化,达到最高热解速率时所对应的温度也发生变化,其中电路板中塑料的失重率最小,并行通信口中塑料的失重率最大。热解速率随着升温速率的提高而增大,在不同的升温速率下,同一样品的热解剩余物质量分数基本一致。电路板中塑料的含碳量高于并行通信口和插槽中的塑料含碳量,并通过动力学研究得出电路板中塑料的活化能最小。 相似文献