Monitoring atmospheric nitrous oxide background concentrations at Zhongshan Station, east Antarctica

At present,continuous observation data for atmospheric nitrous oxide(N_2O) concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongshan Station(69°22′25″S,76°22′14″E),east Antarctica during the period of 2008–2012,and their interannual and seasonal characteristics were analyzed and discussed.The mean N_2O concentration was 321.9 n L/L with the range of 320.5–324.8 n L/L during the five years,and it has been increasing at a rate of 0.29% year-1.Atmospheric N_2O concentrations showed a strong seasonal fluctuation during these five years.The concentrations appeared to follow a downtrend from spring to autumn,and then increased in winter.Generally the highest concentrations occurred in spring.This trend was very similar to that observed at other global observation sites.The overall N_2O concentration at the selected global sites showed an increasing annual trend,and the mean N_2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere.Our result could be representative of atmospheric N_2O background levels at the global scale.This study provided valuable data for atmospheric N_2O concentrations in east Antarctica,which is important to study on the relationships between N2 O emissions and climate change.     

区域大气环境容量及其区域配置研究

以重庆市涪陵区为例,在了解区域大气环境功能区划及区域大气环境质量现状的前提下,采用A-P值法,对涪陵区十三五期间大气环境容量进行研究,并对辖区内的污染负荷进行预测,在此基础上,对大气污染总量控制指标进行分配.研究结果表明,在涪陵区化工园区的二氧化硫排放量已达到或超过总量控制指标,需要制定削减计划,新兴工业园区污染物排放量虽远小于总量控制指标,但根据城市发展规划需进行结构优化与合理布局.     

电解锰企业环境影响评价存在的问题与改进研究

电解锰行业是典型的“两高一资”行业,废渣、废水产生量大,污染物复杂程度高,环境影响较为复杂.目前电解锰生产项目的环评工作的重点一般针对企业产生的常规污染物进行分析,存在工艺技术调研范围窄、对行业特征污染物分析不细致、依赖末端治理忽视源头减少污染物产生量等问题,应结合行业技术的发展趋势,强化工艺比选、引导企业应用先进技术,从源头减少污染物的产生量,并深入分析行业特征污染物的环境影响,提高环境影响评价的水平.     

环境空气质量新标准对博罗县空气质量评价结果的影响

利用博罗县城自动监测站2015年的环境空气自动监测数据,分析了实施《环境空气质量标准》(GB3095-2012)对博罗县城空气质量评价的影响.研究发现,若采用新标准,博罗县城空气中PM2.5和O3将出现不同程度的超标,达标率从99.4％下降到88.5％;PM2.5和O3的纳入是导致空气质量达标率下降的最主要原因,NO2标准的收严和CO的纳入未对博罗县城空气质量评价造成影响.     

天津市海洋环境风险综合评价研究

评价结果显示:天津海域总体上处于中低风险态势,中低风险海域面积分别约占海域面积的59.18%和24.90%;高风险海域占海域面积的比例为15.92%,碎片化地分布于近岸的汉沽大神堂牡蛎礁海洋特别保护区、北塘旅游区、大港湿地、天津港、南港工业区等敏感或重点海域.评价成果可为天津海洋环境风险管控、海域资源使用配置、海洋环境保护规划等提供有益借鉴.     

Towards Real‐Time Continental Scale Streamflow Simulation in Continuous and Discrete Space

The National Weather Service (NWS) forecasts floods at approximately 3,600 locations across the United States (U.S.). However, the river network, as defined by the 1:100,000 scale National Hydrography Dataset‐Plus (NHDPlus) dataset, consists of 2.7 million river segments. Through the National Flood Interoperability Experiment, a continental scale streamflow simulation and forecast system was implemented and continuously operated through the summer of 2015. This system leveraged the WRF‐Hydro framework, initialized on a 3‐km grid, the Routing Application for the Parallel Computation of Discharge river routing model, operating on the NHDPlus, and real‐time atmospheric forcing to continuously forecast streamflow. Although this system produced forecasts, this paper presents a study of the three‐month nowcast to demonstrate the capacity to seamlessly predict reach scale streamflow at the continental scale. In addition, this paper evaluates the impact of reservoirs, through a case study in Texas. Validation of the uncalibrated model using observed hourly streamflow at 5,701 U.S. Geological Survey gages shows 26% demonstrate PBias ≤ |25%|, 11% demonstrate Nash‐Sutcliffe Efficiency (NSE) ≥ 0.25, and 6% demonstrate both PBias ≤ |25%| and NSE ≥ 0.25. When evaluating the impact of reservoirs, the analysis shows when reservoirs are included, NSE ≥ 0.25 for 56% of the gages downstream while NSE ≥ 0.25 for 11% when they are not. The results presented here provide a benchmark for the evolving hydrology program within the NWS and supports their efforts to develop a reach scale flood forecasting system for the country.     

Facile fabrication of highly catalytic-active Ag2CO3/AgBr/graphene oxide ternary composites towards the photocatalytic wastewater treatment

Environmental Science and Pollution Research - Ag2CO3/AgBr/graphene oxide (Ag2CO3/AgBr/GO) ternary composites with different percentages of GO were fabricated by a facile co-precipitation strategy....     

Denitrification potential of riparian soils in relation to multiscale spatial environmental factors: a case study of a typical watershed,China

The objective of this study was to test the hypothesis that environmental regulators of riparian zone soil denitrification potential differ according to spatial scale within a watershed; consequently, a second objective was to provide spatial strategies for conserving and restoring the purification function of runoff in riparian ecosystems. The results show that soil denitrification in riparian zones was more heterogeneous at the profile scale than at the cross-section and landscape scales. At the profile scale, biogeochemical factors (including soil total organic carbon, total nitrogen, and nitrate–nitrogen) were the major direct regulators of the spatial distribution of soil denitrification enzyme activity (DEA). At the cross-section scale, factors included distance from river bank and vegetation density, while landscape-scale factors, including topographic index, elevation, and land use types, indirectly regulated the spatial distribution of DEA. At the profile scale, soil DEA was greatest in the upper soil layers. At the cross-section scale, maximum soil DEA occurred in the mid-part of the riparian zone. At the landscape scale, soil DEA showed an increasing trend towards downstream sites, except for those in urbanized areas.     

Organophosphate pesticide exposure and child health in China

Currently, organophosphate pesticides (OPs) are widely used for agriculture in China and around the world. A few epidemiological studies have examined the association between exposure to OPs and children’s health, but these studies reported inconsistent results. In view of the limitations of testing techniques and the intrinsic incompleteness of scientific evidence from current studies, we have considered some issues which may be interpreted and handled with caution.