RF内星轮(闭式)精密温锻工艺

叙述了RF内星轮塑性变形的工艺分析,提出了RF内星轮制造的(闭式)精密温锻工艺,阐明了新技术取代旧工艺的优点.     

Heterogeneous reaction of NO2 on the surface of montmorillonite particles

The studies on heterogeneous reactions over montmorillonite, which is a typical 2:1 layered aluminosilicate, will benefit to the understanding of heterogeneous reactions on clay minerals. Montmorillonite can be classified as sodium montmorillonite or calcium montmorillonite depending on the cation presented between the different layers. Using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), the heterogeneous reaction mechanism of NO₂ on the surface of montmorillonite was firstly investigated. Results showed that the reaction of NO₂ on the surface of sodium and calcium montmorillonite fit a first-order kinetics, and the reaction duration of calcium montmorillonite was longer than that of sodium montmorillonite under the dry condition. For either sodium or calcium montmorillonite, the uptake coefficient decreased as humidity increased.     

罗时江湿地对总氮、总磷削减效果的初步分析

本研究考察了罗时江湿地对污染水体中总氮和总磷的脱除效率,湿地出口处与入口处总氮总磷的变化规律及总磷、总氮的综合降解系数。结果表明:罗时江湿地对总氮的平均去除效率为50.8%,对总磷的平均去除效率为24.4%;湿地出口水体总氮含量的变化与入口水体总氮含量的变化不一致,出口水体中总磷含量的变化与入口水体中总磷含量的变化基本保持一致;总氮、总磷的平均综合降解系数分别为0.414d-1、0.225d-1。     

Mechanism of Hg oxidation in the presence of HCl over a commercial V2O5–WO3/TiO2 SCR catalyst

Experiments were conducted in a fixed-bed reactor containing a commercial V₂O₅/WO₃/TiO₂ catalyst to investigate mercury oxidation in the presence of HCl and O₂. Mercury oxidation was improved significantly in the presence of HCl and O₂, and the Hg⁰ oxidation efficiencies decreased slowly as the temperature increased from 200 to 400°C. Upon pretreatment with HCl and O₂ at 350°C, the catalyst demonstrated higher catalytic activity for Hg⁰ oxidation. Notably, the effect of pretreatment with HCl alone was not obvious. For the catalyst treated with HCl and O₂, better performance was observed with lower reaction temperatures. The results showed that both HCl and Hg⁰ were first adsorbed onto the catalyst and then reacted with O₂ following its adsorption, which indicates that the oxidation of Hg⁰ over the commercial catalyst followed the Langmuir–Hinshelwood mechanism. Several characterization techniques, including Hg⁰ temperature-programmed desorption (Hg-TPD) and X-ray photoelectron spectroscopy (XPS), were employed in this work. Hg-TPD profiles showed that weakly adsorbed mercury species were converted to strongly bound species in the presence of HCl and O₂. XPS patterns indicated that new chemisorbed oxygen species were formed by the adsorption of HCl, which consequently facilitated the oxidation of mercury.     

“一带一路”沿线国家水资源禀赋及开发利用分析

水资源是基础性的战略资源,开展“一带一路”沿线国家水资源研究对于促进“一带一路”的科学建设具有重要意义。基于世界银行与联合国粮农组织水资源数据库,从水资源开发利用角度入手,分析“一带一路”沿线国家水资源自然禀赋、利用状况,在此基础上进一步分析水资源开发潜力。结果表明：（1）从水资源禀赋来看,“一带一路”沿线国家地表水、地下水和水资源总量均以俄罗斯、中国、东南亚和南亚地区相对较高,中亚、西亚等地区相对较低;人均水资源量则以中东欧、俄罗斯和东南亚地区较高,西亚、南亚地区较低;“一带一路”沿线国家外来水依赖率整体表现为跨境河流下游高,上游及海岛国家低。（2）就水资源利用而言,“一带一路”沿线国家用水量整体呈现“东多西少”的格局,人均用水量表现为“中亚最高,周边较低”的特点;用水结构亚洲国家多以农业用水为主,中东欧国家则多以工业用水为主。（3）水资源开发潜力分析发现,阿拉伯半岛地区各国水资源开发潜力很低,中东欧及东南亚地区水资源开发潜力很高。     

不同排放源对华东地区PM2.5影响的数值模拟

使用中尺度气象-化学耦合模式WRF-Chem针对MEIC源清单中五大部门来源（工业源、电力源、民用源、交通源和农业源）对华东地区PM_2.5的影响进行了模拟研究,主要得到以下结论：春夏秋季PM_2.5约40%~60%来源于工业源,冬季由于采暖供热燃用大量散烧煤,导致民用源对PM_2.5的贡献最大,在山东、安徽和江苏省等高值区贡献率超过50%;农业源、电力源和交通源对PM_2.5影响的季节差异不大,农业源贡献约20%~30%,交通源和火电源贡献约10%.因此冬季需主要控制民用源排放,春夏秋季主要控制工业源排放,其次是农业源排放.一次PM_2.5在工业、电力和民用源贡献的PM_2.5中所占比例可达50%~60%;NO₃^-和NH+4在交通源贡献的PM_2.5中总比例可达53%,在农业源中总比例高达93%;由于模式对SO₄^2-模拟偏低,SO₄^2-在工业源和电力源贡献的PM_2.5中占比约5%~15%;OC对来自民用源的PM_2.5有30%的贡献,BC对来自交通源的PM_2.5有15%的贡献;Na⁺和Cl^-对PM_2.5的贡献在各大来源中均低于3%.     

Stimulation impact of electric currents on heterotrophic denitrifying microbial viability and denitrification performance in high concentration nitrate-contaminated wastewater

Electric current stimulation has been shown to have a positive influence on heterotrophic denitrifying microbial viability and has the potential to improve wastewater denitrification performance. This study investigated the effects of varying current densities on microbial activity and NO_3~- removal efficiency under heterotrophic conditions.NO_3~-removal rate was highest at an applied current density of 400 mA/m~2. However, the optimum removal efficiency of total inorganic nitrogen(TIN; 99%) was achieved when the current density was fixed at 200 m A/m~2. Accumulation of NH_4~+-N and NO_2~--N byproducts were also minimized at this current density. The activity of heterotrophic denitrifying microorganisms was much higher at both 200 and 400 mA/m~2. Moreover, the average adenosine-5′-triphosphate(ATP)content(an indicator of cell metabolism) at a current density of 1600 mA/m~2 was lower than that under no current, indicating heterotrophic denitrifying microbial activity can be inhibited at high current densities. Hence, direct electrical stimulation on the activity of heterotrophic denitrifying microorganisms in the developed system should be lower than 1600 mA/m~2. This study improves the understanding of electric current influence on heterotrophic denitrifying microorganisms and promotes the intelligent application of direct electrical stimulation on wastewater treatment processes.     

中国CDM项目开发现状及存在问题分析研究

清洁发展机制(CDM)是国际社会实现温室气体减排的履约机制之一。目前中国已成为CDM市场的主要输出国,但在CDM项目开发过程中还存在很多问题,例如区域分布不平衡、碳排放权交易标准不统一、缺乏激励机制等。在经济发展和节能减排的双重压力下,中国政府声明将严格遵守《巴黎协定》,正在积极落实已提出的到2020年控制温室气体排放行动目标,并向联合国提交了到2030年的"国家自主贡献"行动目标。中国的积极行动推动了全球气候问题的解决。     

蛋白质及无机离子对纳滤膜去除PFOS的影响

以全氟辛烷磺酸（PFOS）为目标去除物,选取牛血清蛋白（BSA）为典型蛋白质类有机物,考察了BSA及其浓度,以及BSA与无机离子共存时,离子强度、离子种类对聚酰胺纳滤膜去除水中PFOS的影响.研究发现,原液中存在BSA时,PFOS的去除率有显著提高,而且BSA浓度越高,PFOS的去除率越高;当BSA与无机离子共存时,离子强度越大,PFOS去除率越高.这可能是因为BSA不但会吸附一部分PFOS,还会造成膜污染,BSA浓度越大,膜污染越严重,膜的筛分能力越强,且膜面与PFOS之间的静电排斥力越大,从而提高了PFOS的截留率.而无机离子的存在减小了BSA分子之间及与膜面之间的静电排斥力,使BSA污染层更加厚实,进一步增强了膜的筛分能力.此外,Ca²⁺提高PFOS去除率的能力优于Na⁺.     

2016~2017年采暖期华北平原东部PM2.5组分特征及来源解析

为掌握华北平原东部地区大气细颗粒物(PM_(2.5))的污染特征与来源,本研究对2016年和2017年这2年采暖期衡水市、沧州市、济南市、德州市、滨州市、淄博市和聊城市的大气细颗粒物、组分特征和来源进行对比分析.结果表明,2016年和2017年采暖期该区域ρ(PM_(2.5))日均值分别为137. 23μg·m-3和111. 83μg·m-3,分别超过《环境空气质量标准》(GB 3095-2012)日均二级标准限值1. 8倍和1. 5倍;水溶性离子质量浓度分别占ρ(PM_(2.5))的53. 32%和47. 04%,二次无机离子(SNA)为主要离子组分; NO_3-/SO_24-比值从1. 35上升至1. 60,同时Cl-浓度下降,表明燃煤源贡献降低;二次有机碳(SOC)在有机碳(OC)中的占比分别为71. 63%和55. 35%,说明该区域二次有机碳占比明显降低;特征元素Fe/Al、Ba/Ni对比分析表明,2017年采暖期机动车源和扬尘源贡献同比上升;后向轨迹结果表明,该区域污染气团主要源于西北方向,但来源于江苏、安徽等地的污染气团携带的颗粒物浓度最高.