基于Models-3的自修正空气质量预报系统及其效果检验

本文介绍了一个以Models-3为基础的自动化空气质量数值预报系统,该系统通过Gambas、Yabasic和R语言等工具进行开发,集成WRF-SMOKE-CMAQ三个模式,可通过监测数据进行自动修正,完成空气质量业务数值预报,并将结果发布到Web服务器上进行呈现。该系统对硬件的要求较低,将部署于一台DELL Optiplex 9010工作站上,设置6km—2km双层嵌套,进行成都市空气质量数值预报。本文分析了成都市2014年1月1日至2014年12月31日的空气质量数值预报结果,评价系统对成都市NO_2、SO_2、PM_(10)、PM_(2.5)、O_3、CO以及空气质量指数(AQI)的预报效果。结果显示,系统对于成都市2014年空气质量变化情况趋势的预报效果较好,302天有效预报中,24小时直接预报的空气质量等级准确率为58.27%,AQI预报相关系数0.71,观测值自动修正预报对24小时空气质量预报具有明显改善效果,使其等级预报准确率达到64.9%,相关系数提高到0.89。     

Mercury in air in an area impacted by strong industrial activities

The concentrations of total gaseous mercury (TGM) and its relevant environmental parameters were measured at a highly industrialized area in the Ban Wall industrial complex (BWIC) in An San city, Korea from March to May 2005. The mean concentrations of Hg measured during the entire study period were computed to be 6.32 ± 8.56 ng m⁻³ (range of 2.32–181 ng m⁻³; N = 1160). Due to the effects of strong man-made activities, the significantly high Hg concentration levels (e.g., at or above 10 ng m⁻³) comprised about 7.5% of all data with the mean of 21.8 ± 26.3 ng m⁻³ (N = 87). By separating the data into daytime and nighttime periods, the Hg values exhibited a notable daytime enhancement possibly due to strong man-made activities during working hours. The results of the correlation analysis indicated the possible relationship between the Hg concentration and the temperature as well as several pollutant species (e.g., NO₂ and NO_x). Evaluation of the Hg data in relation with the air mass transport pattern confirms that the Hg concentration levels in this industrial area are affected most eminently by local, rather than distant, pollution sources.     

Suppressing effect of goethite on PCDD/F and HCB emissions from plastic materials incineration

Polyethylene (PE) and polyvinyl chloride (PVC) are the leading plastics in total production in the world. The incineration of plastic-based materials forms many chlorinated compounds, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). In this study the addition of goethite (alpha-FeOOH) was investigated to determine its suppressing effect on the emission of PCDD/Fs and hexachlorobenzene (HCB) during the combustion of wastes containing PE and PVC. Goethite was being considered since it acts as a dioxin-suppressing catalyst during incineration. Results showed that incorporation of goethite greatly reduced the generation of PCDD/Fs and HCB in the exhaust gas and fly ash. The concentration of PCDD/Fs in flue gas decreased by 45% for lab-scale and 52% for small incinerator combustion experiments, where the goethite ratios in feed samples were 0.54% and 0.34%, respectively. Under the same conditions, the concentration of HCB in flue gas decreased by 88% and 62%, respectively. The present study showed a possible mechanism of the suppressing effect of the goethite for PCDD/F formation. It is likely that iron chlorides react with particulate carbon to form organo-chlorine compounds and promote PCDD/F formation in the gas phase. XRD analysis of combustion ash revealed that the goethite was partially dehydrated and converted to alpha-Fe(2)O(3) and Fe(3)O(4) but no iron chlorides formation. Therefore the goethite impregnated plastics can contribute the reduction of PCDD/Fs and HCB in the exhaust gas during incineration of MSW.     

Influence of a soil enzyme on iron-cyanide complex speciation and mineral adsorption

Cyanide is commonly found as ferrocyanide [Fe(II)(CN)(6)](-4) and in the more mobile form, ferricyanide [Fe(III)(CN)(6)](-3) in contaminated soils and sediments. Although soil minerals may influence ferrocyanide speciation, and thus mobility, the possible influence of soil enzymes has not been examined. In a series of experiments conducted under a range of soil-like conditions, laccase, a phenoloxidase enzyme derived from the fungi Trametes versicolor, was found to exert a large influence on iron-cyanide speciation and mobility. In the presence of laccase, up to 93% of ferrocyanide (36-362ppm) was oxidized to ferricyanide within 4h. No significant effect of pH (3.6 and 6.2) or initial ferrocyanide concentration on the extent or rate of oxidation was found and ferrocyanide oxidation did not occur in the absence of laccase. Relative to iron-cyanide-mineral systems without laccase, ferrocyanide adsorption to aluminum hydroxide and montmorillonite decreased in the presence of laccase and was similar to or somewhat greater than that of ferricyanide without laccase. Laccase-catalyzed conversion of ferrocyanide to ferricyanide was extensive though up to 33% of the enzyme was mineral-bound. These results demonstrate that soil enzymes can play a major role in ferrocyanide speciation and mobility. Biotic soil components must be considered as highly effective oxidation catalysts that may alter the mobility of metals and metal complexes in soil. Immobilized enzymes should also be considered for use in soil metal remediation efforts.     

人类活动影响下的四湖地区湿地景观格局分析

湿地景观空间结构研究是湿地生态研究的核心之一，景观功能性的性质和发挥，影响着湿地的物质流、信息流和能量流的特征，进而影响湿地区域的资源开发利用与保护。运用景观的空间格局指数，在遥感和GIS技术的支持下，结合江汉平原四湖地区的湿地农业的区域特点，确定了 四湖地区湿地景观分类系统，为了更好地定量分析四湖地区湿地景观格局的特点，我们选取了三类景观格局指数来定量描述于景观空间格局，即基本空间格局指标（多样性、均匀度及优势度）、景观空间构型指标（聚集工、破碎化）及斑块特征指标（斑块分维数），比较系统地分析四湖地区湿地景观空间格局。在此基础上探讨了人类干扰对四湖地区湿地同的结构和空间演替的影响。     

车载储氢瓶泄漏及车库内通风方式研究

为研究车库内燃料电池汽车氢气意外泄漏后的浓度分布情况,采用ANSYS软件,通过分析可燃性气体体积、水平方向和垂直方向氢气的扩散分布、不同泄漏位置氢气的扩散情况,研究6种不同通风方式对氢气意外泄漏扩散分布的影响,针对车库内氢气泄漏的特性,在通风方式上引入侧墙底部送风和侧墙顶部送风方式。研究结果表明：底部送风能显著加快氢气的扩散和排出。垂直高度上氢气浓度分布不均,侧墙顶部送风能使顶部堆积的氢气向下扩散,降低最大气体浓度;在墙角泄漏会由于墙壁的影响导致氢气堆积,对墙角局部通风尤为重要。研究结果可为氢燃料电池汽车专用车库的通风设计提供重要参考。     

中药渣生物炭的制备及其对水中四环素的吸附特性研究

以中药废渣为原料,四环素为目标污染物,采用限氧热解法在热解温度分别为300℃、500℃和700℃的条件下制备了不同中药渣生物炭(Biochar, BC),并采用比表面积分析仪(BET)、扫描电子显微镜(SEM)、傅里叶红外光谱分析仪(FTIR)、X射线光电子能谱仪(XPS)、X射线衍射仪(XRD)等手段对不同中药渣生物炭的物理化学性质进行了表征;通过中药渣生物炭对水中四环素(Tetracycline, TC)的吸附试验,研究了不同中药渣生物炭对水中四环素的吸附特性,考察了溶液初始浓度、吸附时间对溶液中四环素去除效果的影响,并结合吸附动力学、吸附等温线拟合结果探究了中药渣生物炭对水中四环素的吸附机制。结果表明：随着热解温度的升高,中药渣生物炭中有机物分解,含氧官能团种类及其相对含量发生变化,其中含氧官能团C—C的相对含量升高、C—H的相对含量降低,中药渣生物炭的芳香化程度增加,且700℃制备的中药渣生物炭对水中四环素的吸附性能更优;中药渣生物炭对水中四环素的吸附量依次为BC700(93.46 mg/g)>BC500(76.32 mg/g)>BC300(32.92 mg/g),...     

Roles of membrane and organic fouling layers on the removal of endocrine disrupting chemicals in microfiltration

To understand the adsorption behavior of endocrine disrupting chemicals(EDCs) is important for enhancing the treatment performance and preventing potential secondary pollution caused by EDCs desorption in a microfiltration system. The dynamic adsorption of four representative EDCs, namely estriol(E3), 17β-estradiol(E2), 17α-ethynylestradiol(EE2), and 4-nonylphenol(4-NP) in a microfiltration system was investigated using the Thomas' model.The product of the equilibrium constant and the total adsorption capacity of the membrane,Ka, for E3, E2, EE2, and 4-NP were 4.91, 9.78, 15.6, and 826, respectively, strongly correlating with the compound octanol–water partition coefficient(KOW). Adsorption appeared to be enhanced when organic fouling formed on the surface of membrane, indicating the role of an additional adsorption column for EDCs acted by a fouling layer in microfiltration. Results of a comparison between the Ka values for clean membrane and fouled membrane illustrated that the significant contribution made by fouling layers may be attributed to the foulant layer's hydrophobicity(in the case of calcium humate layer) and thickness(in the case of calcium alginate layer). This study provided a novel perspective to quantitatively analyze the dynamic adsorption behavior of trace pollutants in membrane process.     

芜湖市大气挥发性有机物污染特征、大气反应活性及源解析

2018年9月至2019年8月对芜湖市城区大气中挥发性有机物（VOCs）进行观测,探讨其污染特征、光化学影响和来源.结果表明,芜湖市大气中VOCs全年平均体积分数为27.86×10^-9,季节变化规律为：秋季（31.16×10^-9） > 夏季（28.70×10^-9） > 冬季（24.75×10^-9） > 春季（24.04×10^-9）,日变化规律呈双峰型,峰值在08：00~09：00时与18：00~19：00时出现,与交通流量的变化有关.芜湖市大气VOCs的平均臭氧生成潜势（OFP）为255.29 μg ·m^-3,不同组分对平均OFP的贡献率排序为：芳香烃（48.83%） > 烷烃（21.04%） > 烯烃（18.32%） > OVOCs（11.47%） > 卤代烃（0.35%）.总气溶胶生成潜势（AFP）为1.84 μg ·m^-3,芳香烃贡献率最高（87.69%）,其次为烷烃（12.31%）.苯/甲苯/乙苯（B/T/E）比值表明,芜湖市大气中苯系物的主要贡献源为机动车排放源和工业排放及溶剂使用源.源解析显示：油气挥发源、机动车排放源、溶剂挥发源、LPG排放源、植物排放源和二次生成源对采样期内的VOCs贡献率分别为11.57%、34.53%、16.63%、20.76%、3.54%和12.97%.     

自养反硝化技术研究进展

介绍了近年来水体硝酸盐污染的原因及危害,阐述了反硝化技术的特点及主要原理,综述了以硫及氢为电子供体的自养反硝化技术的发展及运用,探讨了其今后的研究方向和前景。