Effect of straw retention on carbon footprint under different cropping sequences in Northeast China

Environmental Science and Pollution Research - Inappropriate farm management practices can lead to increased agricultural inputs and changes in atmospheric greenhouse gas (GHG) emissions, impacting...     

NO2 catalytic formation,consumption, and efflux in various types of diesel particulate filter

Environmental Science and Pollution Research - The high NO2/NOX ratio in the after-treatment system is beneficial to its performance and achieved by NO catalytic conversion in diesel oxidation...     

Performance and microbial community of a membrane bioreactor system——Treating wastewater from ethanol fermentation of food waste

In this study, a lab-scale biological anaerobic/anaerobic/anoxic/membrane bioreactor(A_-~3MBR) was designed to treat wastewater from the ethanol fermentation of food waste,a promising way for the disposal of food waste and reclamation of resources. The 454 pyrosequencing technique was used to investigate the composition of the microbial community in the treatment system. The system yielded a stable effluent concentration of chemical oxygen demand(202 ± 23 mg/L), total nitrogen(62.1 ± 7.1 mg/L), ammonia(0.3 ±0.13 mg/L) and total phosphorus(8.3 ± 0.9 mg/L), and the reactors played different roles in specific pollutant removal. The exploration of the microbial community in the system revealed that:(1) the microbial diversity of anaerobic reactors A_1 and A_2, in which organic pollutants were massively degraded, was much higher than that in anoxic A_3 and aerobic MBR;(2) although the community composition in each reactor was quite different, bacteria assigned to the classes Clostridia, Bacteroidia, and Synergistia were important and common microorganisms for organic pollutant degradation in the anaerobic units, and bacteria from Alphaproteobacteria and Betaproteobacteria were the dominant microbial population in A_3 and MBR;(3) the taxon identification indicated that Arcobacter in the anaerobic reactors and Thauera in the anoxic reactor were two representative genera in the biological process. Our results proved that the biological A_-~3MBR process is an alternative technique for treating wastewater from food waste.     

Simulated reaction of formaldehyde and ambient atmospheric particulate matter using a chamber

The reaction of HCHO with Beijing winter's real ambient particulate matter(PM) inside a 3.3 m~3 Teflon Chamber was conducted in this study. NO_2, O_3 and H_2O gases were removed from the ambient aerosol before entering into the chamber. The decays of HCHO were monitored(acetylacetone spectrophotometry method) during the reactions at different PM number concentrations(N_a) and relative humidities(RHs), and the formed particulate formate was detected by IC and XPS techniques. The results showed that when RH was10%–15%, the decay rate of HCHO in the chamber was higher with the existence of PM from relatively clean days(with number concentration(N_a) 200,000 particle/L, 0.35–22.5 μm)compared to dirty days(N_a 200,000 particle/L, 0.35–22.5 μm). When RH increased to 30%–45%, PM can hardly have significant influences on the decay of HCHO. The formations of formate on the reacted PM were consistent with the HCHO decay rates at different ambient PM N_aand RH conditions. This is a first study related to the "real" ambient PM reacted with HCHO and suggested that in the clean and low RH days, PM could be an effective medium for the conversion of HCHO to formate.     

Effect of MoO3 on vanadium based catalysts for the selective catalytic reduction of NOx with NH3 at low temperature

The selective catalytic reduction(SCR) activities of the MoO_3 doped V/WTi catalysts prepared by the incipient wetness impregnation method at low temperature were investigated.The results showed that the addition of MoO_3 could enhance the NO_ xconversion at low temperature and the best SCR activity was obtained when the dosage of MoO_3 reached5 wt.%. The NH3-TPD and DRIFTS experiments indicated that the addition of MoO_3 changed the type and number of acid sites on the surface of catalysts and reaction activities of acid sites were altered at the same time. The redox capacity and amount of active oxygen species got improved for V3Mo5/WTi catalyst, which could be confirmed by the H_2-TPR and transient response experiments. Water vapor inhibited the NO_xconversion at low temperature. Deposition of ammonium sulfate or bisulfate might be main reason for the loss of catalytic activity in the presence of SO_2 at low temperature. Choosing the suitable NH_3/NO ratio and elevation of reaction temperature both could weaken the influence of SO_2 on the SCR activity of the V3Mo5/WTi catalyst. Thermal treatment of the deactivated catalyst at350°C could get the low temperature activity recovered. The decrease of GHSV improved the de NO_x efficiency at low temperature and we speculated that the rational technological process and operation parameters could contribute to the application of this kind of catalysts in real industrial environment.     

外浮顶原油储罐VOCs排放核算参数对排放量的影响研究

依据美国环保署颁布的储罐VOCs排放量核算公式,从环境参数、原油参数和储罐结构参数3个方面对外浮顶储罐VOCs排放的影响进行了研究,其中包括了边缘密封排放挂壁排放、浮盘附件排放和浮盘着陆期间排放等几个相关排放核算数学公式。结果表明:环境风速增大,环境温度升高或太阳辐射强度提高均导致排放量增大;原油温度升高或原油周转量增加也导致排放量增加;储罐直径增加,罐漆颜色浅,或者罐壁锈蚀情况好会降低VOCs排放量。     

外浮顶原油储罐VOCs泄漏损耗及排放量核算

介绍了国内外浮顶原油储罐VOCs泄漏损耗形式。结合美国环保署(EPA)发布的AP-42中第7章储罐的VOCs相关排放公式,建立了外浮顶原油储罐VOCs排放量核算的方法,并对核算方法的应用进行了举例分析,有助于掌握现阶段原油外浮顶储罐的泄漏损耗量,为推进企业绿色低碳发展,控制原油储罐VOCs总量排放提供参考。     

进口危险化学品风险评估管理模式研究

剖析了国外化学品风险管理理念,梳理了我国进口危险化学品质量安全状况,对进口危险化学品的风险因素进行评估,并探索建立以风险信息数据库、安全标识备案审核制度、差异化管理等模块组成的管理模式,为推动我国进口危险化学品检验检疫模式改革提供参考。     

大庆市草原和湖泊生态保护建设研究

通过对大庆草甸草原和湖泊湿地发生发展自然生态过程的分析,以大庆生态环境的整体性特征为基础,提出草甸草原是大庆生态环境的基础,湖泊湿地是大庆生态环境的特色.以保护和恢复为主巩固草原生态基础地位,以生态重建为主突出湖泊湿地特色.对生态功能正常发挥的草原,以生态保护为主,对生态功能退化草原,以生态恢复为主.对油田生产区的草原,重视生态功能和景观效应.以生态重建为主突出湖泊湿地特色,通过地表水结构的调整增加生态系统的活力和生态服务功能.草甸草原和湖泊湿地的保护与利用要扬长补短、协同并进.     

SCREEN3模型在大气环境管理中的应用研究

基于高斯扩散的单源估算模式SCREEN3计算佛山市环境统计企业的SO2排放最大落地浓度距离,发现全市工业企业SO2排放最大落地浓度距离为0.4~13.5 km.其中水泥和火电等高架源的最大落地浓度的距离最远.佛山市及五区纳入环境统计的重点废气排放企业平均的SO2排放最大落地浓度距离为2.9~4.9 km,能直接影响国控监测点位的企业合计37家,其中40%为高明区的企业.该结果证明加强空气质量国控监测点位周边至少5 km内废气排放企业的督查有利于空气质量的改善.