University, Diss., 2005--Heidelberg.

Ziel der Arbeit ist die Beschreibung des Membranverhaltens bzw. der Membraneigenschaften bei der Regeneration von Extraktionsmitteln der Metallextraktion durch Trennung von beladenen und unbeladenen Extraktionsmitteln mittels Ultrafiltration. Dazu wurden die Trennleistungen als Funktion von Druck, Temperatur und Solventzusammensetzung für verschiedene Membranmaterialien und -typen untersucht. Anhand von Sorptionsversuchen konnte die Löslichkeit der Komponenten der organischen Phase in den verschiedenen Polymermatrizen von Membranen aus regenerierter Cellulose bzw. Polyethersulfon und die adsorptive Gelschichtbildung als Funktion der Solventzusammensetzung, der Temperatur und des Membranmaterials aufgezeigt werden. Der Einfluss der Sorption, des Quellens und Kompaktierens auf das Materialverhalten konnte mittels einer Hochdruckmikrowaage und eines Laserscanner-Messstandes ermittelt werden. Die durch Veresterung und Wasserstoffbrückenbindung entstehende Gelschicht auf der Membranoberfläche, die letztendlich für die Rückgewinnung von unbeladenem Extraktionsmittel ausschlaggebend ist, kann mit Hilfe der Röntgenphotoelektronenspektroskopie, Rasterelektronen- und Rasterkraftmikroskopie nachgewiesen werden.

Weil in Sachsen die vorhandene Datenbasis zu Schwermetallgehalten in Düngemitteln, Bodenhilfsstoffen und Kultursubstraten im Jahr 2005 zu gering war, wurde ein Projekt mit dem Vorhabenstitel „Bestimmung und Bewertung der Schwermetallgehalte von Düngemitteln, Bodenhilfsstoffen und Kultursubstraten“ durchgeführt, um rechtzeitig Ableitungen für einen sachgerechten und effizienten Hoheitsvollzug in Sachsen treffen zu können. Das Forschungsprojekt beinhaltete folgende Ziele: - Bestimmung von anorganischen Schadstoffen in Düngemitteln, Bodenhilfsstoffen und Kultursubstraten - Bewertung der Analysenergebnisse auf der Grundlage geltender Rechtsverordnungen - Ableitung von Kontrollschwerpunkten für die Düngemittelverkehrskontrolle auf gesicherter Datenbasis. Im vorliegenden Heft werden die Ergebnisse dieses Projektes dargestellt.

Der Bericht informiert über die Emissionssituation 2012 im Freistaat Sachsen. Betrachtet werden die anthropogen verursachten Emissionen von Treibhausgasen, klassischen sowie persistenten organischen Luftschadstoffen und Schwermetallen sowie deren Verursacher. Dazu gehören insbesondere Groß- und Kleinfeuerungsanlagen und emissionserklärungspflichtige Anlagen aus Industrie, Verkehr und Landwirtschaft. Die Auswertung erfolgt nach dem Prinzip der Quellenbilanz, d. h. die Emissionen werden dort erfasst, wo sie entstehen, unabhängig vom Ort des Endverbrauchs.

The sequential extraction scheme BCR 701 has been applied to the upper 2 cm layer of 39 sediment samples from Inner Kingston Basin, Ontario. The samples were also been characterized by water content, loss on ignition at 550°C and 950°C and by particle size distribution. Methodological problems occurred during particle size analysis, caused by agglomerating effects, mainly driven by organic matter, which is fairly resistant against oxidation by hydrogen peroxide due to natural manganese dioxide particles in the sediments. This leads to an overestimation of the clay content. For the same reason, the digestion in step 3 of the sequential extraction was insufficient, so that typical organic bound metals were found in the residual fraction. From factor and cluster analysis of all data three main substrate element associations were derived: The carbonate group contains Ca, Sr, LOI 950°C from calcite, and in step 2 additional Mg extracted from dolomite. Secondly, the organic associations include LOI 550°C, water content and clay content, and finally the metals (except from carbonate bound metals) which are more or less linked to the organic associations. Regionalized maps using inverse distance weighting or ordinary Kriging have been judged to be less precise and informative than point data maps using a classification following equal standard deviation distances and additional statistical information, box plots and histograms. Compared to the geogenic background, all samples show a significant metal enrichment in the mobile fractions, so that they could easily be remobilized during changing environmental conditions. Higher enrichment rates have been detected around the city of Kingston, mainly the harbour region, and close to the outlet of Kingston s sewage treatment plant. Generally, local contamination can easily be detected and differentiated according to their origin from sequential extraction data.

Plants might contain heavy metals from the surrounding polluted environment. Medicinal herb and plants, commonly used in Vietnam, may pose a risk to public health when polluted with heavy metals such as Pb, Cd and As. This study aims to investigate the content of Pb, Cd, and As in five selected herb plants (Phyllanthus urinaria L., Plantago asiatica L., Eleusine indica L., Wedelia chinensis (Osbeck) Merr, and Artemisia vulgaris L.). The samples were collected from natural sites in some provinces in northern Vietnam. The concentrations of Pb, Cd, and As were determined by the Inductively coupled plasma mass spectrometry (ICP-MS) method. The content of Pb, Cd and As was 0.247 ÷ 32.080 mg kg-1, 0.000 ÷ 1.099 mg kg-1, 0.000 ÷ 2.261 mg kg-1, respectively. A total of 50 out of the 58 investigated samples had concentrations of Pb, Cd, As lower than the permissible values of the World Health Organization (WHO). The remaining samples had contents of Pb or Cd or As significantly higher than the permissible limit defined by WHO. / Thực vật có thể bị ô nhiễm do hấp thụ kim loại nặng từ môi trường ô nhiễm xung quanh. Các loại cây thảo dược được sử dụng phổ biến làm thuốc chữa bệnh ở Việt Nam. Chúng có thể gây nguy hiểm cho sức khỏe cộng đồng khi bị ô nhiễm kim loại nặng (Pb, Cd…vv.). Nghiên cứu này nhằm điều tra hàm lượng Pb, Cd và As trong năm loại cây thảo dược (cây Diệp Hạ Châu, cây Mã Đề, cây Cỏ Mần Trầu, cây Sài Đất và cây Ngải Cứu). Các mẫu cây này được lấy từ các địa điểm mọc tự nhiên ở một số tỉnh khác nhau thuộc khu vực miền bắc Việt Nam. Hàm lượng của Pb, Cd, và As được xác định bằng phương pháp ICP-MS. Hàm lượng Pb, Cd và As trong các mẫu phân tích lần lượt nằm trong khoảng là 0.247 ÷ 32.080 mg. Kg-1, 0.000 ÷ 1.099 mg. Kg-1, 0.000 ÷ 2.261 mg. Kg-1. 50 trên 58 mẫu phân tích có hàm lượng Pb, Cd, As thấp hơn giới hạn cho phép do tổ chức y tế thế giới (WHO) quy định. Có 8 trên 58 mẫu cây phân tích có hàm lượng Pb hoặc, Cd hoặc As cao hơn tiêu chuẩn giới hạn của WHO.

The contamination of heavy metals in surface waters is an environmental concern due to their persistence and non-degradation that poses a risk to the ecosystem and human health. Microalgae have been known for their ability to remove metals from wastewater and to produce biodiesel. In this study, the copper (Cu) stress on the growth and lipid contents of the green microalgal Pediastrum sp. were evaluated along with the removal capacity. The green microalga was grown in a culture medium with the presence of copper at concentrations of 0, 0.1, 0.5, 2, 5 and 15 mg/L for one week. Results indicated that the growing tolerance levels of Pediastrum sp. in the presence of copper up to 2 mg/L and Cu inhibited the algal growth with the 96h-EC50 value of 6.67 mg/L. However, the Pediastrum sp. showed a promising metal removal efficiency. Cu removal was from 83 to 95% by Pediastrum sp. with an initial concentration of Cu less than 2 mg/L. The presence of a low level of Cu increased the lipid yield up to 18%, but a high concentration of Cu has resulted in low removal efficiencies and decreasing lipid accumulation. The present study suggested the potential of employing green microalgae for wastewater treatment and biodiesel. / Ô nhiễm kim loại nặng trong nước mặt đang là vấn nạn môi trường ở nhiều quốc gia bởi vì kim loại nặng tồn tại lâu, khó có khả năng phân hủy và gây ảnh hưởng đến sức khỏe con người và hệ sinh thái. Vi tảo từ lâu được biết đến vì có khả năng loại bỏ kim loại nặng trong nước thải đồng thời tích lũy lipid cho sản xuất nhiên liệu sinh học. Trong nghiên cứu này khảo sát các tác động của đồng (Cu) như ức chế tăng trưởng, ảnh hưởng lên hàm lượng lipid tích lũy, khả năng loại bỏ kim loại cũng nhưhàm lượng kim loại tích lũy trong nội bào lên vi tảo lục Pediastrum sp. Vi tảo lục được phơi nhiễm với Cu ở các nồng độ 0, 0,1, 0,5, 2, 5 và 15 mg/L trong thời gian 1 tuần ở điều kiện phòng thí nghiệm. Kết quả cho thấy vi tảo lục Pediastrum sp. có khả năng chống chịu với Cu ở ngưỡng nồng độ nhỏ hơn 2 mg/L. Nồng độ gây ức chế sinh trưởng 50% sau 96h (96h-EC50) là 6,67 mg/L. Pediastrum sp. cho thấy có khả năng loại bỏ hiệu quả Cu ở ngưỡng nồng độ thấp hơn 2 mg/L với khả năng loại bỏ Cu lên đến 95%. Ở nồng độ Cu 0,1 và 0,5 mg/L cũng cho thấy gia tăng hàm lượng lipid 18% so với lô đối chứng, tuy nhiên khả năng loại bỏ kim loại Cu và hàm lượng lipid tích lũy giảm đi đáng kể khi Cu đồng ở ngưỡng 5 mg/L và 15 mg/L. Nghiên cứu này cho thấy có thể sử dụng vi tảo Pediastrum sp. để xử lý ô nhiễm Cu ở nồng độ thấp và thu hồi lipid cho sản xuất nhiên liệu sinh học.

Metals occur naturally and are commonly found as contaminants in areas where industrial and municipal effluents are discharged. Aquatic sediments/environments are often polluted by heavy metals due to the temporal variations in anthropogenic input of contaminants via atmospheric deposition, catchment runoff, effluent inflow and dumping from industrial transportation, mining, agricultural and waste disposal sources [EPA, 1989]. The transfer of contaminants associated with settling inorganic particulates and/or biotic detritus from the water column to the sediments, no disturbance of sediments by physical mixing, slumping or bioturbation after deposition, no post-depositional degradation or mobility of the contaminants and the establishment of a reliable time axis. Therefore, metal contamination in aquatic environment is one of the problems. Rivers, coastal waters, sediments, soils, etc. were mostly contaminated by industrial and mining activities. Recently, the metal discharged from the industries have been controlled in the most developed countries. Even so, till the heavy metals dispersed in river sediments still need to be dealt with. Mainly, characterization, transformation, transport and fate of metal contaminants in the sediment to the aquatic environment need to be studied, because the sediment has great capacity to accumulate the contaminants. Exploitation and utilization of mines discharges heavy metals into the environment and contaminates neighboring aquatic ecosystem...

Metals occur naturally and are commonly found as contaminants in areas where industrial and municipal effluents are discharged. Aquatic sediments/environments are often polluted by heavy metals due to the temporal variations in anthropogenic input of contaminants via atmospheric deposition, catchment runoff, effluent inflow and dumping from industrial transportation, mining, agricultural and waste disposal sources [EPA, 1989]. The transfer of contaminants associated with settling inorganic particulates and/or biotic detritus from the water column to the sediments, no disturbance of sediments by physical mixing, slumping or bioturbation after deposition, no post-depositional degradation or mobility of the contaminants and the establishment of a reliable time axis. Therefore, metal contamination in aquatic environment is one of the problems. Rivers, coastal waters, sediments, soils, etc. were mostly contaminated by industrial and mining activities. Recently, the metal discharged from the industries have been controlled in the most developed countries. Even so, till the heavy metals dispersed in river sediments still need to be dealt with. Mainly, characterization, transformation, transport and fate of metal contaminants in the sediment to the aquatic environment need to be studied, because the sediment has great capacity to accumulate the contaminants. Exploitation and utilization of mines discharges heavy metals into the environment and contaminates neighboring aquatic ecosystem...

Gegenstand der vorliegenden Arbeit ist die Synthese und Charakterisierung neuer chromophorer Catecholderivate mit ausgeprägten push-pull-pi-Systemen. Die solvatochromen Eigenschaften dieser Verbindungen werden in Abhängigkeit der Wasserstoffbrückenbindungsdonor- und -akzeptorfähigkeit sowie Lösungsmitteldipolarität diskutiert. Mit entsprechenden methoxy- und dimethoxyfunktionalisierten Catecholderivaten ist es möglich, vergleichende Struktur-Eigenschaftsbeziehungen aufzustellen. Durch Untersuchungen zu den Wechselwirkungen der chromophoren Catechole mit Schwermetallionen kann gezeigt werden, dass die synthetisierten Verbindungen als Sensoren eingesetzt werden können. In der vorliegenden Arbeit wird des Weiteren die Adsorption der Catecholderivate an Metalloxide beschrieben. Mit Farbstoffen sensibilisierte Oberflächen stellen derzeit ein interessantes Forschunggebiet dar. Ferner wird über die Umsetzung der Catecholderivate mit Trialkoxysilanen zu zwitterionischen, spirozyklischen, pentakoordinierten lambda5Si-Silicaten sowie mit Tetraalkoxysilanen zu dianionischen, hexakoordinierten lambda6Si-Silicaten berichtet. Besonderes Augenmerk lag dabei auf UV/vis-spektroskopischen Untersuchungen.