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361.
快速的城镇化进程带来城市碳排放的快速增长,准确的城市水平碳排放数据对于制定科学合理的碳减排政策极为关键,明确碳排放源的关键类别可以做到有的放矢和精准管控.但是目前中国碳排放数据的研究主要集中在国家、地区和省级层面,城市水平由于所需基础数据的不透明和不准确,长久以来缺乏完整的碳排放清单.为解决该问题,在以前相关研究的基础上,通过省级能源平衡表,尝试利用合理的分配指标从省级碳排放数据估算出下属城市的碳排放,构建了一套自上而下的城市能源消耗碳排放估算方法.通过与现有可获得的城市水平数据进行对比,发现估算差距均在10%以内,证明了该方法的可行性和准确性,并尝试在时间尺度进行了扩展.为获取在时间和空间上均连续的中国城市能源消耗碳排放数据提供了科学的方法和合理的思路,也能为各城市分配减排任务和城市间进行减排协商提供可靠的数据支撑. 相似文献
362.
Juexiu Li Xiaoping He Bing Pei Xianwei Li Diwen Ying Yalin Wang Jinping Jia 《环境科学学报(英文版)》2019,31(3):282-290
Iron ore sintering is a major source of gaseous and particulate pollutants emission in iron smelt plant. The aim of present study is to characterize the volatile organic compounds(VOCs) emission profiles from iron ore sintering process. Both sinter pot test and sinter simulation experiment were conducted and compared. Out results showed that sinter process produced large quantity of VOCs together with NOxand SO_2. VOCs and NO were produced simultaneously in sinter pot test from 3 to 24 min after ignition, flowed by SO_2 production from 15 min to the end of sintering. Total VOCs(TVOC) concentration in sinter flue gas was affected by the coal and coke ratio in sinter raw material. The maximum TVOC concentration was 34.5 ppm when using 100% coal as fuel. Sinter simulation experiments found that the number of VOCs species and their concentrations were found by sinter temperature. The largest VOCs species varieties were obtained at 500 °C. Benzene, toluene,xylene and ethylbenzene were major VOCs in sinter flue gas based on the results from both simulation test and sinter pot. It thus demonstrated that in addition to NO_x, SO_2 and metal oxide particles, sinter flue gas also contained significant amount of VOCs whose environmental impact cannot be ignored. Based on our work, it is timely needed to establish a new VOC emission standard for sinter flue gas and develop advanced techniques to simultaneously eliminate multi-pollutants in iron ore sinter process. 相似文献
363.
364.
High nitrate(NO_3~-)loading in water bodies is a crucial factor inducing the eutrophication of lakes.We tried to enhance NO_3~-reduction in overlying water by coupling sediment microbial fuel cells(SMFCs)with submerged aquatic plant Ceratophyllum demersum.A comparative study was conducted by setting four treatments:open-circuit SMFC(Control),closed-circuit SMFC(SMFC-c),open-circuit SMFC with C.demersum(Plant),and closed-circuit SMFC with C.demersum(P-SMFC-c).The electrochemical parameters were documented to illustrate the bio-electrochemical characteristics of SMFC-c and P-SMFC-c.Removal pathways of NO_3~- in different treatments were studied by adding quantitative~(15)NO_3~- to water column.The results showed that the cathodic reaction in SMFC-c was mainly catalyzed by aerobic organisms attached on the cathode,including algae,Pseudomonas,Bacillus,and Albidiferax.The oxygen secreted by plants significantly improved the power generation of SMFC-c.Both electrogenesis and plants enhanced the complete removal of NO_3~- from the sediment–water system.The complete removal rates of added~(15)N increased by 17.6% and 10.2% for SMFC-c and plant,respectively,when compared with control at the end of experiment.The electrochemical/heterotrophic and aerobic denitrification on cathodes mainly drove the higher reduction of NO_3~- in SMFC-c and plant,respectively.The coexistence of electrogenesis and plants further increased the complete removal of NO_3~- with a rate of 23.1%.The heterotrophic and aerobic denitrifications were simultaneously promoted with a highest abundance of Flavobacterium,Bacillus,Geobacter,Pseudomonas,Rhodobacter,and Arenimonas on the cathode. 相似文献
365.
Jingjing Zhang Lei Tong Chenghui Peng Huiling Zhang Zhongwen Huang Jun He Hang Xiao 《环境科学学报(英文版)》2019,31(3):372-382
Simultaneous and continuous measurements of visibility, meteorological parameters and air pollutants were carried out at a suburban site in Ningbo from June 1, 2013 to May 31,2015. The characteristics of visibility and their relationships with air pollutants and meteorological factors were investigated using multiple statistical methods. Daily visibility ranged from 0.6 to 34.1 km, with a mean value of 11.8 km. During the 2-year experiment,43.4% of daily visibility was found to be less than 10.0 km and only 9.2% was greater than 20.0 km. Visibility was lower in winter with a frequency of 53.4% in the range of 0.0–5.0 km.Annual visibility had an obvious diurnal variation, with the lowest and highest visibility being 7.5 km at approximately 06:00 local time and 15.6 km at approximately 14:00 local time, respectively. Multiple correspondence analysis(MCA) indicated that the different ranges of visibility were significantly affected by different levels of pollutants and meteorological conditions. Based on the analyses, visibility was found to be an exponential function of PM_(2.5) concentrations within a certain range of relative humidity. Thus, nonlinear models combining multiple linear regressions with exponential regression were subsequently developed using the data collected from June 2014 to May 2015, and the data from June 2013 to May 2014 was used to evaluate the performance of the model. It was demonstrated that the derived models can quantitatively describe the relationships between visibility, air quality and meteorological parameters in Ningbo. 相似文献
366.
Tao M Fengkui Duan Kebin He Yu Qin Dan Tong Guannan Geng Xuyan Liu Hui Li Shuo Yang Siqi Ye Beiyao Xu Qiang Zhang Yongliang Ma 《环境科学学报(英文版)》2019,31(9):8-20
With rapid economic growth and urbanization, the Yangtze River Delta(YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014–2016. In recent years, the concentrations of all air pollutants, except O_3,decreased. Spatially, the PM_(2.5), PM_(10), SO_2, and CO concentrations were higher in the northern YRD region, and NO_2 and O_3 were higher in the central YRD region. Based on the number of non-attainment days(i.e., days with air quality index greater than 100), PM_(2.5) was the largest contributor to air pollution in the YRD region, followed by O_3, PM_(10), and NO_2.However, particulate matter pollution has declined gradually, while O_3 pollution worsened.Meteorological conditions mainly influenced day-to-day variations in pollutant concentrations. PM_(2.5) concentration was inversely related to wind speed, while O_3 concentration was positively correlated with temperature and negatively correlated with relative humidity.The air quality improvement in recent years was mainly attributed to emission reductions.During 2014–2016, PM_(2.5), PM_(10), SO_2, NO_x, CO, NH_3, and volatile organic compound(VOC)emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. Our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region. 相似文献
367.
O3 decomposition catalysts with excellent performance still need to be developed. In this study, Ag-modified manganese oxides (AgMnOx) were synthesized by a simple co-precipitation method. The effect of calcination temperature on the activity of MnOx and AgMnOx catalysts was investigated. The effect of the amount of Ag addition on the activity and structure of the catalysts was further studied by activity testing and characterization by a variety of techniques. The activity of 8%AgMnOx for ozone decomposition was significantly enhanced due to the formation of the Ag1.8Mn8O16 structure, indicating that this phase has excellent performance for ozone decomposition. The weight content of Ag1.8Mn8O16 in the 8%AgMnOx catalyst was only about 33.76%, which further indicates the excellent performance of the Ag1.8Mn8O16 phase for ozone decomposition. The H2 temperature programmed reduction (H2-TPR) results indicated that the reducibility of the catalysts increased due to the formation of the Ag1.8Mn8O16 structure. This study provides guidance for a follow-up study on Ag-modified manganese oxide catalysts for ozone decomposition. 相似文献
368.
Qing Wu Li He Zhong Wei Jiang Yang Li Ting Ting Zhao Yu Han Li Cheng Zhi Huang Yuan Fang Li 《环境科学学报(英文版)》2019,31(12):203-212
Efficient removal of non-biodegradable and hazardous dyes from wastewater remains a hot research topic. Herein, a rationally designed a Cu(Ⅱ)-based metal–organic gel(Cu-MOG) with a nanoporous 3 D network structure prepared via a simple one-step mixing method was successfully employed for the removal of cationic dyes. The Cu-MOG exhibited high efficiency, with an adsorption capacity of up to 650.32 mg/g, and rapid adsorption efficiency, with the ability to adsorb 80% of Neutral Red within 1 min. The high adsorption efficiency was attributed to its large specific surface area, which enabled it to massively bind cationic dyes through electrostatic interaction, and a nanoporous structure that promoted intra-pore diffusion. Remarkably, the Cu-MOG displayed size-selective adsorption, based on adsorption studies concerning dyes of different sizes as calculated by density functional theory. Additionally, the adsorption performance of the Cu-MOG still maintained removal efficiency of 100% after three regeneration cycles. These results suggested that the Cu-MOG could be expected to be a promising and competitive candidate to conveniently process wastewater. 相似文献
369.
目的研究电子束物理气相沉积热障涂层对单晶高温合金高周疲劳性能的影响,为热障涂层在涡轮叶片上的应用提供技术支持。方法采用真空电弧镀和电子束物理气相沉积工艺制备YSZ热障涂层,进行900℃条件下高周疲劳性能测试,采用扫描电镜对测试后的试样表面、断口形貌进行观察与分析。结果在900℃、380 MPa条件下,带涂层的DD6单晶试棒循环次数(Nf)超过了107,420 MPa条件下超过了106。通过对DD6单晶试棒断口分析,失效后的带涂层试棒仍以DD6单晶常见滑移解离形式发生破坏。结论高周疲劳性能测试条件下,带YSZ热障涂层的试棒中粘结层率先产生垂直微裂纹,但是裂纹扩展延伸中发生氧化钝化,之后DD6基体沿正常的滑移方向从表面向内部疲劳扩展,带涂层的试棒疲劳裂纹并非由涂层微裂纹直接扩展形成,热障涂层对DD6单晶高温合金高周疲劳性能影响较小。 相似文献
370.