固态反应法制备FeHY催化剂及其催化降解活性艳蓝的性能研究

分别以NaY、NH4Y和HY沸石为载体,以乙酰丙酮铁为铁源,采用固态反应法制备了铁负载量均为10%（w）的FeNaY-10、FeNH4Y-10和FeHY-10催化剂。考察了各催化剂对活性艳蓝（KN-R）的降解效果,其中FeHY-10的催化降解效果最佳。采用XRD和FTIR技术对FeHY-10催化剂进行表征。表征结果显示,FeHY催化剂晶体结构仍然保持了Y分子筛特有的孔道结构,铁物种在Y 分子筛表面高度分散。催化降解实验表明,催化降解KN-R的最佳工艺条件为KN-R溶液（质量浓度为300 mg/L）加入量为50 mL、溶液pH为2、催化剂FeHY-25（铁负载量为25%（w））加入量为0.281 3 g、H2O2质量浓度为6.356 g/L、降解温度为35 ℃、降解时间为140 min,在此工艺条件下FeHY催化剂对KN-R的降解率为97.4%。     

基于MODIS NDVI的攀枝花市植被覆盖变化及其驱动力#br#

攀枝花市位于金沙江与雅砻江的交汇处是长江上游生态脆弱区,也是天然林保护工程和退耕还林工程等的重点实施区。基于2001~2010年MODIS NDVI数据,以及同时期的气象数据和其他辅助数据,利用最大值合成法（MVC）、趋势分析法以及线性相关分析等方法研究了攀枝花市植被覆盖时空变化及其与气候因素和人类活动的关系。研究结果表明：攀枝花市植被覆盖整体较高,属于高植被覆盖区域,年际尺度上,植被覆盖呈上升的趋势,增长速率为0.02/10 a;从年内来看,9月NDVI达到最大值,NDVI最小值出现在3月;植被覆盖在水平空间上呈“南低北高”的分布特征,并在垂直空间上呈现出显著的差异性,研究区植被覆盖分别在海拔2 000~3 000 m、坡度30°~40°达到最大值;受水热条件的影响,阴坡（0°~45°, 315°~360°）植被覆盖高于阳坡（135°~225°）,而平地（-1°）植被覆盖度最低;就整个研究区而言,植被退化的面积与增加的面积分别占0.7%和44.4%,增加的面积远大于退化的面积;年际尺度上植被受气温的影响高于受降水的影响;大规模生态工程建设是研究区植被覆盖增加的主要驱动因素。 关键词： 植被覆盖变化;归一化植被指数;气候变化;人类活动;攀枝花市     

How do local communities adapt to climate changes along heavily damaged coasts? A Stakeholder Delphi study in Ky Anh (Central Vietnam)

The Central Vietnamese coast faces increasing impacts on the local livelihoods of coastal communities as a result of the increasing natural hazards which include tropical storms, heavy rains, and floods. A challenge for the local populations is improving their adaptation capacity to climate change hazards in a sustainable way. This study deals with the impacts of climate change-associated hazards and adaptation capacity in coastal communes of the Ky Anh district, Ha Tinh province along the coast in Central Vietnam. A combination of the Stakeholder Delphi technique and the DPSIR (drivers–pressures–states–impacts–responses) framework was used. Delphi questionnaires allowed assessing the consensus among the respondents of a stakeholder group. Twenty questions and 20 statements were listed reflecting the DPSIR components. Thirty-six panel members, which were randomly selected from four stakeholder groups which included local authorities, farmers, fishermen, and fish traders, were involved in a two-round Delphi process. The results show that, both agricultural and non-agricultural sectors are main drivers (D); migration, calamities, population growth, mineral mining, aquaculture processing, and agriculture are main pressures (P); changes in the frequency of extreme weather events, increasing intensity of storms, floods, and droughts indicate main states (S); changes in agricultural land use and productivity are main impacts (I); construction of and upgrading dykes and irrigation systems should be the principal responses (R) in the vision of the local stakeholders. The Kendall’s W value for the second round is 0.681, indicating a high degree of consensus among the panel members and confidence in the ranks. Overall, the study advocates developing sustainable ecosystems, an upgraded New Rural Planning, and renewable energy strategies as the main local adaptations to climate change hazards in this area.     

城市交通干道绿地砷污染评价

为了研究城市砷污染的现状及不同区域砷污染的空间差异性,以吉林市表层土壤为研究对象,在交通干道的绿化带和磨盘山保护区采集35个土壤样本,进行pH、有机质及砷含量的测定。采用单项污染指数、污染累计指数法等对土壤砷污染进行评价,并运用方差分析的方法对不同区域的砷污染进行了差异比较。研究表明:吉林市街道砷含量为26.43 mg/kg,为磨盘山自然土壤砷含量的4.08倍,为吉林市砷土壤背景值7.26倍;吉林市砷总体超标率12.9%。江北工业区、吉林大街和解放大路的单项污染指数分别为1.34、0.95、0.87,整体达到轻微污染水平。江北工业区和吉林大街、解放大路的变异系数相差不大,依次为0.13、0.11、0.17。土壤砷的污染累积指数为3.21,且由北向南递减,因此,砷污染主要来自于江北工业区的工业"三废"污染。     

Conventional, microwave, and ultrasound sequential extractions for the fractionation of metals in sediments within the Petrochemical Industry, Serbia

In this paper, the main objective was fractionation of Cd, Cu, Ni, Pb, Zn, Ca, Fe, and K in certificate material and sediment samples gathered from and around the Petrochemical Industry using the conventional, microwave and ultrasonic sequential extraction. Microwave oven and ultrasound bath were used as an energy source for achieving faster extraction. Additional heating and boiling of samples were avoided by using lower power and shorter time for microwave and ultrasound extraction. Precision and accuracy of procedure were evaluated by using certificate material (BCR701). Acceptable accuracy of metals (87.0–111.3 %) was achieved for all three-step sequential of conventional extraction protocol. An accuracy of the fourth step has been verified with two certificate materials: BCR143R and 146R. The range of total extracted metal concentrations from sediments was similar for all three extraction techniques. A significant high percentage of Cd, Cu, and Zn were obtained after extraction of the exchangeable and acid soluble sediment fraction. Principal component analysis of values obtained after determination of risk assessment code using conventional and ultrasound sequential extraction show similarity of these values. Accuracy, recovery, and risk assessment code values imply that ultrasound sequential extraction is a more suitable, accelerated sequential extraction procedure (30 min per extraction step) than microwave extraction in applied conditions.     

Characterizations of volatile organic compounds during high ozone episodes in Beijing,China

Air samples were collected in Beijing from June through August 2008, and concentrations of volatile organic compounds (VOCs) in those samples are here discussed. This sampling was performed to increase understanding of the distributions of their compositions, illustrate the overall characteristics of different classes of VOCs, assess the ages of air masses, and apportion sources of VOCs using principal compound analysis/absolute principal component scores (PCA/APCS). During the sampling periods, the relative abundance of the four classes of VOCs as determined by the concentration-based method was different from that determined by the reactivity approach. Alkanes were found to be most abundant (44.3–50.1%) by the concentration-based method, but aromatic compounds were most abundant (38.2–44.5%) by the reactivity approach. Aromatics and alkenes contributed most (73–84%) to the ozone formation potential. Toluene was the most abundant compound (11.8–12.7%) during every sampling period. When the maximum incremental reactivity approach was used, propene, toluene, m,p-xylene, 1-butene, and 1,2,4-trimethylbenzene were the five most abundant compounds during two sampling periods. X/B, T/B, and E/B ratios in this study were lower than those found in other cities, possibly due to the aging of the air mass at this site. Four components were extracted from application of PCA to the data. It was found that the contribution of vehicle exhaust to total VOCs accounted for 53% of VOCs, while emissions due to the solvent use contributed 33% of the total VOCs. Industrial sources contributed 3% and biogenic sources contributed 11%. The results showed that vehicle exhausts (i.e., unburned vehicle emissions + vehicle internal engine combustion) were dominant in VOC emissions during the experimental period. The solvent use made the second most significant contribution to ambient VOCs.     

水产养殖自身污染及其生物修复技术

介绍了生物修复的概念、水产养殖存在的自身污染问题及其主要生物修复技术.营养物污染、药物污染和底泥富集污染是水产养殖存在的主要自身污染问题;微生物修复、水生植物修复和水生动物修复是污染养殖水域生物修复的3种主要形式;微生物的有效性、生物入侵、二次污染、修复生物的季节性和非水生植物的利用等方面是实施生物修复应注意的主要方面.最后指出,推行清洁生产、实行生态养殖是水产养殖业可持续发展的出路.     

Performance of a full-scale biofilm system retrofitted with an upflow multilayer bioreactor as a preanoxic reactor for advanced wastewater treatment

To enhance nitrogen removal in an existing microbial contact oxidation (MCO) system with a treatment capacity of 900 m3/d, an upflow multilayer bioreactor (UMBR) was chosen as a preanoxic reactor for the removal of organic matter and nitrate. The removal performance of the retrofitted plant was evaluated during the startup phase at a low temperature in winter. The high removal (>80%) of organic matter and suspended solids in the UMBR provided stable nitrification conditions in the MCO system, as a result of the substantial reduction in organic matter and solids loaded onto the MCO system. This treatment system showed a stable nitrogen removal efficiency of 75.3%, even in the low temperature range 7 to 10 degrees C. Phosphorus was completely removed by chemical precipitation. Production rates of excess sludge, as a function of the loads of influent flowrate and biological oxygen demand (BOD), were 0.022 kg dry solid/m3 wastewater and 0.132 kg dry solid/kg BOD.     

环境风险评价中氯气泄漏扩散的计算

根据HJ/T169-2004((建设项目环境风险评价技术导则>(简称<导则>),对某化工厂使用的液氯钢瓶的事故源进行分析.采用<导则>推荐的Cox和Carpenter稠密气体扩散模型,在氯气泄漏的初期,将其作为重气泄漏扩散进行计算,得到重气云团温度、半径、卷入空气质量和质量浓度随扩散时间的变化关系.计算结果与非重气扩散高斯模式的计算结果有较大差异.因此,对涉及氯气的项目进行环境风险评价时,应重视氯气作为重气泄漏扩散的环节.