Polarographische Bestimmung von Nickel und Chrom in Klärschlämmen Polarographic Determination of Nickel and Chromium in Sewage Sludge

The contents of Ni and Cr in sewage sludge with high and low amounts of heavy metals were investigated by polarography. The DIN-digestion (aqua regia) was used, and the resulting solution was treated with H₂O₂/UV (90 °C, 60 min) for further destroying of the organic material. Besides, the solution of the DIN-digestion was examined with AAS (flame) and ICP-OES. With the determination of Ni it was shown that after digestion with aqua regia no further treatment with H₂O₂/UV is necessary. Contrariwise it was found that for the determination of Cr a H₂O₂/UV photolysis is necessary followed by further steps to get good agreement with AAS and ICP results as well as with the certified values of a sludge of the Community Bureau of Standards.     

Comparison of spawning seasons,age, growth rates,and food of two sympatric species of searobins,Prionotus carolinus and Prionotus evolans,from Long Island Sound

Prionotus carolinus and Prionotus evolans were collected from many locations within Long Island Sound in 1971–1973, and in 1976–1977. Data from earlier collections in Block Island Sound (1943–1945) were also included. A total of 1751 specimens, 960 P. carolinus and 791 P. evolans was examined within these two time periods. Both species entered the Sound in April and spawned during June and July. P. evolans appeared to spawn slightly earlier in summer than P. carolinus. Adults began to leave the Sound after spawning and were usually absent after November. Young-of-the-year were taken regularly from August to November and, occasionally in water over 20 m deep, into February when the bottom water temperature was 1.4°C. At the end of the first growing seasons both species exhibited large variations in standard lengths. Back-calculations from scale annuli measurements indicated that linear growth rates during the juvenile years were similar in both species. However, P. evolans was considerably heavier than P. carolinus. During adulthood P. evolans was not only longer and heavier than P. carolinus, but lived longer. Growth rates are described by the following equations: P. carolinus L_t+1=9.60+0.68 (L_t), and p. evolans L_t+1=7.70+0.80 (L_t). Both species were opportunistic feeders, and crustaceans were clearly the dominant group of prey. Young-of-the-year, between 3–6 cm, ate copepods. As they grew they ate larger prey, such as Neomysis americana, Diastylis quadrispinosus, various species of amphipods of small sizes, and juvenile Crangon septemspinosus. Older fish ate larger sizes of these same prey, a number of species of crabs, juvenile Homarus americanus, and Squilla empusa. Occasionally they ate polychaetes, molluscs, and juvenile fish. Partitioning of the resources of Long Island Sound by these two species appeared to be by prey size. P. evolans ate prey that, on the average, were slightly larger than those eaten by P. carolinus. Furthermore, P. evolans ate a greater amount of nektonic species than P. carolinus, which appeared to prefer benthonic invertebrates.     

The coagulation of dissolved239, 240Pu in estuaries as determined from a mixing experiment

A mixing experiment, using large volumes (100 l) of filtered (< 1 μm) freshwater and seawater end-members, was performed to simulate and investigate the chemical reactivity of^{239, 240}Pu during estuarine mixing. An organic-rich freshwater with a relatively high concentration (0.8 dpm/100 l) of dissolved^{239, 240}Pu was used as one end-member; Buzzards Bay seawater (dissolved^{239, 240}Pu= 0.04dpm/100l) was the other. The results demonstrate that dissolved^{239, 240}Pu in the freshwater undergoes extensive and rapid coagulation under simulated estuarine conditions. There is a strong correlation between the amount of coagulation of dissolved^{239, 240}Pu, humic acids (HA), and Fe. The extent of coagulation of all three constituents increases with increasing salinity and the net extent of their removal is 53%, 57%, and 100% for Pu, HA, and Fe respectively. As has been documented for Fe in freshwater, dissolved^{239, 240}Pu appears to be stabilized by naturally occurring humic substances to form negatively charged colloids which are then coagulated by seawater cations. The extrapolation of these experimental results to real estuaries will require additional research.     

Grußwort des Befehlshabers der Flotte

Ohne Zusammenfassung     

On the intermediate drift burst model

A modification of the presently existing intermediate drift burst model by Kuijpers (1975) and Bernold (1983) is suggested. It is shown that whistler solitons cannot be responsible for intermediate drift bursts. Here, they are interpreted as the radio signature of localized formstable whistler wave packets propagating along the magnetic field in a coronal loop. In the frame of this modified model, the magnetic field strengths derived from fiber burst data agree with previous estimates by Dulk and McLean (1978).     

Degree of Geochemical Similarity (DOGS): a simple statistical method to quantify and map affinity between samples from multi-element geochemical data sets

The 42 element, 1190 sample Mobile Metal Ion subset of the National Geochemical Survey of Australia database was used to develop and illustrate the concept of Degree of Geochemical Similarity of soil samples. Element concentrations were unified to parts per million units and log(10)-transformed. The degree of similarity of pairs of samples of known provenance in the Yilgarn Craton was obtained using least-squares linear regression analysis and demonstrated that the method successfully assessed the degree of similarity of soils related to granitoid and greenstone lithologies. Exploratory Data Analysis symbol maps of all remaining samples in the database against various reference samples were used to obtain correlation maps not only for granitoid- and greenstone-related soil types but also to distinguish between, for example, samples derived from marine vs regolith carbonate. Likewise, the distribution of soil samples having a geochemical fingerprint similar to mineralised provinces (e.g. Mount Isa) can be mapped, and this can be used as a first-order prospection tool.     

A brief overview of the ACEP project: Ecosystem Processes in the KwaZulu-Natal Bight§

This introductory paper lays the basis for this supplementary issue by briefly presenting the state of knowledge on the KwaZulu-Natal (KZN) Bight at the start of this multi-disciplinary, multi-institutional, ship-based research project that ran from 2009 to 2013. The rationale and aims of the project are also described. The project was a major component of the South African Department of Science and Technology’s African Coelacanth Ecosystem Programme (ACEP), which has been prominent in supporting research on the east coast of South Africa and the wider South-West Indian Ocean. Pivotal to this was the RS Algoa, which was made available for two 30-day surveys (winter and summer) in the KZN Bight by the Department of Environmental Affairs. Although some aspects of the bight ecology are known, much of the research is dated and fragmented, and required refreshing and consolidation in order to produce a platform upon which the understanding of the region’s ecosystem functioning could be established. Much of the oceanographic knowledge is also dated, with no dedicated surveys and significant measurements undertaken since 1989. The overarching theme of the KZN Bight project was to examine the relative importance of sources of nutrients to the central KZN coast and how these are taken up and recycled in the ecosystem, and to describe aspects of the benthic biodiversity, which is poorly described in much of this region. An ambitious project, its accessibility to a ship-based research platform and the diverse scientific skills of the participating scientists allowed considerable success, as reflected in the papers that follow.