Auswertung langzeitlicher Meßreihen zur aeroben Abbauleistung der Uferpassage einer Wassergewinnungsanlage am Niederrhein     

E. Denecke 《洁净——土壤、空气、水》1997,25(6):311-318

Evaluation of Long-term Measurements Concerning the Aerobic Degradation Performance of the Subsoil Passage of a Water Catchment at the Lower Rhine The magnitude of the biodegradation of organics during bank filtration was investigated and exemplary quantified at a drinking water catchment in the lower river Rhine area. The catchment is situated at an undercut slope where the Rhine has a steady flow. The observed segment of the quarternary aquifer was free of iron and manganese and showed even under anaerobic conditions no heterotrophic denitrification. This facilitated the assignment and the balance of oxygen consumption and the determination of inorganic carbon due to the metabolic activity of heterotrophic organisms. In particular the progressive curve of the base neutralization capacity up to pH 8.2 of the bank filtered water proved to be a good measure for the biological activity in the river bottom. In the months from summer to autumn there was an increased biological activity. The observed oxygen consumptions could be attributed to the biodegradation of dissolved organic matter by 35 to 45% only. Obviously the particulate organic matter after the rise in temperature during summer takes part in a substantial manner considered little until now. Today the Rhine is regarded as a largely rehabilitated river with respect to oxygen consuming pollutions. The observations demonstrate, that in such flowing waters the particulate organic matter, which should mainly consist of withered organisms, may have a dominant influence on the concentration of oxygen in the bank-filtered water in summertimes.  相似文献   

长江口区水中的汞   总被引：1，自引：0，他引：1  

张淑美  郑舜琴  庞学忠 《海洋科学》1989,13(5):40-43

本文报告了1985年8月和1986年3月长江口区表层水中溶解汞、颗粒汞和总汞的含量及分布。并讨论了长江水与海水混合过程中汞的行为。  相似文献   

冬季东海典型海域颗粒有机碳的垂直分布   总被引：7，自引：1，他引：7  

赵继胜  姬泓巍  郭志刚 《海洋科学》2003,27(6):59-63

就冬季东海陆架典型海域POC的垂直分布进行了研究。结果表明受黄海沿岸流影响的中陆架砂质区POC和悬浮体含量高,POC的垂直分布表现为从表层到底层逐渐增高;悬浮体含量低的中陆架济州岛西南泥质区和砂质区,POC含量低,其垂直分布比较均匀。POC的垂直分布与海水体中的总悬浮颗粒物浓度、陆源沉积物供应和海洋生物作用密切相关。  相似文献   

9810号台风过程厦门近岸海域POC的变化特征   总被引：2，自引：1，他引：2  

薛健宏  杨逸萍  郭卫东  胡明辉 《台湾海峡》2000,19(3):269-275

本文研究了９８１０号台风影响下九龙江口及厦门西港表层海水颗粒有机碳（ＰＯＣ）的变化特征及其与某些环境因子的关系,除厦门西港低潮水外,台风期间ＰＯＣ含量的迅速增大,此“冲击期”共维持３ｄ后ＰＯＣ值迅速回落,进入“恢复期”。台风期间,九龙江口高低潮,厦门西港高潮表层水ＰＯＣ含量分别为０．７３９、１．３１９和０．８４８ｍｇ／ｄｍ＾３,是非台风状况下的１．１、１．９和１．４倍,陆源有机物的输入和底质再悬浮作用是控制表层水ＰＯＣ含量的主要因素,而厦门西港低潮水ＰＯＣ含量受台风作用影响较小,碎屑ＰＯＣ为厦门近岸海域表层海水ＰＯＣ的主要组成部分。ＰＯＣ与溶解态Ｎ、Ｐ营养盐有一定正相关性,暗示其可能来自颗粒物有机Ｎ、Ｐ的生物降解。  相似文献   

Mass balance of lead through a small macrotidal estuary: The Morlaix River estuary (Brittany,France)     

Ph. Monbet 《Marine Chemistry》2006

Dissolved and particulate lead were measured over an annual cycle (12 surveys between February 1998 and January 1999) in the Morlaix River estuary (Brittany, France). The concentrations were investigated in both the water column and the sediment of the river bottom in relation to hydrological conditions. In the water column, dissolved and particulate lead concentrations ranged from 0.1 to 4.4 nM and from 0.04 to 1.9 μmol g^− 1, respectively. Lead concentrations in surface sediment varied from 0.04 to 0.19 μmol g^− 1 and concentrations in the sediment pore water of the estuary were below the detection limit. Compared with the ranges known for pristine estuaries, concentrations of Pb in the water column of the Morlaix River estuary were found to be much higher. Concentrations of Pb also exceeded the lower range of those known for industrialized estuaries. Extensive agricultural activities in the drainage basin may be responsible for Pb levels above pristine conditions. Furthermore, the sediment appeared not to be contaminated. A mass balance was constructed quantifying all known sources and sinks for the Pb in the estuary. Riverine input accounts for most of the total annual metal flux. Burial in sediments was the major sink within the estuary, which acts as a trap especially for the particulate lead. The mass balance shows that the metal accumulation ranged between 414.6 and 446.0 kg year^− 1.  相似文献   

Reduction of particulate matter and gaseous emission from marine diesel engines using a catalyzed particulate filter   总被引：1，自引：0，他引：1  

Cherng-Yuan Lin 《Ocean Engineering》2002,29(11):1327-1341

Diesel engines are used widely as the power sources of coastal ships and international vessels primarily due to their high thermal efficiency, high fuel economy and durable performance. However, the gaseous and solid substances exhausted from diesel engines during the combustion process cause air pollution, in particular around harbor regions. In order to effectively reduce particulate matter and gaseous pollution emissions, a catalyzed particulate filter was equipped in the tail pipe of a marine diesel engine. The engine's performance and emission characteristics under various engine speeds and torques were measured using a computerized engine data control and acquisition system accompanied with an engine dynamometer. The effectiveness of installing a catalyzed particulate filter on the reduction of pollutant emissions was examined. The experimental results show that the exhaust gas temperature, carbon monoxide and smoke opacity were reduced significantly upon installation of the particulate filter. In particular, larger conversion of carbon monoxide to carbon dioxide — and thus larger CO₂ and lower CO emissions — were observed for the marine diesel engine equipped with a catalyzed particulate filter and operated at higher engine speeds. This is presumably due to enhancement of the catalytic oxidation reaction that results from an exhaust gas with stronger stirring motion passing through the filter. The absorption of partial heating energy from the exhaust gas by the physical structure of the particulate filter resulted in a reduction in the exhaust gas temperature. The particulate matter could be burnt to a greater extent due to the effect of the catalyst coated on the surface of the particulate filter. Moreover, the fuel consumption rate was increased slightly while the excess oxygen emission was somewhat decreased with the particulate filter.  相似文献   

Deforestation modifying terrestrial organic transport in the Rio Tapajós, Brazilian Amazon     

N. Farella  M. Lucotte  P. Louchouarn  M. Roulet 《Organic Geochemistry》2001,32(12)

The concentration and biomarker compositions of sedimentary organic matter (OM) as well as fine and coarse suspended particles were analysed to identify the impact of deforestation on the transport of terrigenous organic matter (OM) in the Rio Tapajós, a major tributary to the Amazon. Substantial shifts in the concentration and composition of recently deposited sedimentary OM suggest that intensive deforestation over the last few decades has considerably modified the natural inputs of sedimentary materials to the aquatic ecosystems by disrupting the terrigenous fluxes of humus and soil materials from the drainage basin. The observed compositional changes of bulk OM and land derived biomarkers (e.g. lignin) in recent sediments illustrate a sedimentary enrichment in OM from soil horizons that, under normal forest cover, tend to be retained in the drainage basin. On average, the recently accumulated OM is nitrogen-rich ((C/N)a=12–15) and more highly degraded ((Ac/Al)v=0.4–0.6 and DHBA/V=0.15–0.20) than deep materials ((C/N)a=20–30, (Ac/Al)v=0.25–0.4, and DHBA/V=0.05–0.10), showing that this recently accumulated material is more humified than original inputs to the aquatic system, and consistent with increased exportation of fine eroded mineral and organic particles from surface soils along river banks. The present study illustrates the relevance of using OM oxidation products in sediment profiles to evaluate deforestation impacts on aquatic ecosystems and to characterize the nature of eroded soil materials, complementing studies on mineral/metal cycling.  相似文献   

The Role of Particulate Matter in the Mobilization of Trace Metals during Anaerobic Digestion of Solid Waste Material Die Bedeutung der partikulären Substanz für die Mobilisierung von Spurenmetallen beim anaeroben Abbau fester Abfallstoffe     

St. Peiffer  U. Becker  R. Herrmann 《洁净——土壤、空气、水》1994,22(3):130-137

Metal ions bound to particulate matter represent the greatest portion (i.e. > 95%) of the total metal content found in leachate from reactor experiments where solid waste material was anaerobically digested. This seems true even though strong complexing agents are in solution which increase the solubility of Pb and Cu by a factor up to 10⁴… 10⁵ over that theoretically predicted according to the solubility of the corresponding sulfide mineral. A titrimetric characterization of the metal ion binding sites of the particulate matter suggests that the metal binding properties of the particulate matter are mainly due to organic, aminoacid-type compounds (amines. thio groups, carboxylic groups) probably of bacterial origin. The change of the concentration of the binding sites with time, together with the change of the composition of the particulate matter indicates that bacterial flocs are suspended in the leachate during the switch from acidogenic to methanogenic conditions — either due to the detachment of bacterial films from the solid material by the intensive gas production or due to the formation of syntrophic methanogenic bacterial associations or a combination of both. A combination of the two factors, strong affinity of bacterial mass to metal ions on the one hand, and suspending of the bacterial mass in the leachate on the other hand, will therefore imply a great mobilizing potential for trace metals. Consequently, the highest concentrations of particulate bound Cd were found in reactor experiments where sewage sludge contaminated with Cd was added to the waste material. An increase of the concentration of dissolved cadmium over the solubility of cadmium sulfide, however, could not be observed.  相似文献   

东海颗粒碳的垂直转移过程   总被引：7，自引：3，他引：7  

郭志刚  杨作升 《海洋与湖沼》1997,28(6):659-664

在１９９３年和１９９４年两个航次中，利用震动式取样从东海陆架取得３个柱状岩芯样品。对其进行了ＰＯＣ，ＰＩＣ，ＰＯＮ含量和粒度分析，并同其上覆水体的ＰＯＣ，ＰＩＣ以及总颗粒物的垂直通量和悬浮体作了比较。  相似文献   

秸秆燃烧对北京秋季气溶胶浓度和短波辐射影响的模拟研究   总被引：1，自引：0，他引：1  

何一滢  韩志伟  刘瑞婷  李嘉伟 《气候与环境研究》2019,24(3):369-382

利用地面细颗粒物（PM2.5）浓度和气象常规观测资料、地基 AERONET观测资料、GFED生物质燃烧排放清单和大气化学—天气耦合模式WRF-Chem,模拟研究了华北地区2014年10月气象要素和大气污染物的时空演变,重点关注北京10月7～11日的一次重霾事件及其天气形势、边界层气象特征、输送路径、PM2.5及其化学成分浓度变化等特征,以及秸秆燃烧对华北和北京地区细颗粒物浓度和地面短波辐射的影响。与观测资料的对比结果显示,模式可以很好地模拟北京地区地面气象要素和PM2.5质量浓度,考虑秸秆燃烧排放源可以明显改进北京PM2.5浓度模拟的准确性,但在重度污染情况下,模式总体上低估气溶胶光学厚度和高估地面短波辐射。10月7～11日北京地区重霾事件主要是不利气象条件下人为污染物累积和区域输送造成,也受到华北地区南部秸秆燃烧的影响。河南北部、河北南部和山东西部大面积秸秆燃烧释放的气态污染物和颗粒物在南风的作用下输送至北京,秸秆燃烧对北京地区地面PM2.5、有机碳（OC）、硝酸盐、铵盐、硫酸盐和黑碳（BC）的平均贡献率分别为24.6%、36.8%、23.2%、22.6%、7.1%和19.8%,秸秆燃烧产生的气溶胶可以导致北京地面平均短波辐射最大减小超过20 W m－2,约占总气溶胶导致地表短波辐射变化的24%。  相似文献