Mobilität von Nitroaromaten im Sandstein infolge Schwefelsäureeintrag zur Uranlaugung

As a result of former in situ leaching activities with sulfphuric acid, nitroaromatic compounds have invaded into cenomanian and turonian sandstone aquifers and mining waters in parts of the uranium mining of Königstein, Germany (Saxony). In the mining area contamination levels of nitrobenzene, mononitrotoluene and dinitrotoluene lead to a partial excess in the drining water guide values. For environmental protection, control and remediation efforts by flooding, more knowledge about contaminant mobility in sandstone, and in intercalated clays and silts, is demanded. A selected experimental area has been flooded to realize and study transport processes under real mining conditions. In this work, we have examined the mobilization of nitroaromatic compounds by flooding waters. The interactions between the nitroaromatic compounds, which are dissolved in the mining water, and the host rocks are discussed. The existing data for strata of varying lithologic conditions suggest that the sorption processes of the compounds investigated are negligible in pure sandstone aquifer layers and significant in the lithologic conditions with a complex mixture of mudstone, siltstone and clay. Several lithologic conditions are demonstrated in contaminant sinks and sources caused by adsorption processes and mobilization of newly connected stagnant pore waters.     

Desertification in Australia: An eye to grass roots and landscapes

Desertification in some form is estimated to have occurred over about 42% of the 5 million km² of arid and semiarid lands in Australia. The most common form of desertification is loss of perennial grasses from grasslands, savannas, and open woodlands, often with a replacement by inedible shrubs. Desertification continues to be a problem, especially during droughts when grazing pressures reduce ground cover, laying bare landscapes to wind and water erosion. But two national programs, Drought Alert and Landcare, are giving new hope in controlling land degradation. Both use a grassroots approach by promoting action through local pastoralist and farmer groups and by encouraging the use of effective techniques for rehabilitating landscapes. A strategic application of ponding banks and contour traps with an eye to the landscape has proven successful in stopping and reversing desertification processes.     

Environmental impact from agrochemicals in Bali (Indonesia)

Irrigation of paddy has been practised for centuries in Bali, based on the use of upland weirs for diverting river waters to irrigate downstreams lands ranging from upland terraces to flat coastal plains. While in earlier times, traditional irrigation practices have met the island's food needs, in recent decades an increasing population has increased food requirements to levels surpassing the productivity of traditional methods. Government assistance programs were initiated beginning in about 1960, and a major new program, called the Bali Irrigation Project, is now being implemented. These programs recognize that little additional farm lands will be available, hence their objective is to increase productivity through intensified agriculture, including the use of high-yield rice varieties and increasing amounts of agricultural chemicals, including both fertilizers and pesticides. The feasibility study for the Bali Irrigation Project included an evaluation of the pollutional effects of agricultural chemicals used in Bali. The study showed that past use of hard organochlorides has pervasively polluted the island's soil and water resources and, while the Government's programs now use only relatively degradable chemicals, considerable environmental damage has already occurred and much care will be needed in avoiding the use of hard toxics in the future. The study also indicated no adverse effects from increased use of fertilizers.     

Comparison of the statolith structures of <Emphasis Type="Italic">Chironex fleckeri</Emphasis> (Cnidaria,Cubozoa) and <Emphasis Type="Italic">Periphylla periphylla</Emphasis> (Cnidaria,Scyphozoa): a phylogenetic approach

The rhopalia and statocysts of Periphylla periphylla (Péron and Lesueur in Ann Mus Hist Nat Marseille 14:316–366,1809) and Chironex fleckeri Southcott (Aust J Mar Freshw Res 7(2):254–280 1956) were examined histologically and showed several homologous characteristics. Differences in sensory area distribution could be connected to a slightly different functionality of equilibrium sensing. In P. periphylla, the statoliths (crystals) grow independently of each other; whereas in C. fleckeri, one large crystal covers the smaller ones. The structures of both statoliths were examined in detail with single-crystal diffraction, microtomography and diffraction contrast tomography. The single compact statolith of C. fleckeri consisted of bassanite as was previously known only for other rhopaliophoran medusae. An origin area with several small oligocrystals was located in the centre of the cubozoan statolith. The origin areas and the accretion of statoliths are similar in both species. Our results lead to the assumption that the single bassanite statolith of C. fleckeri (Cnidaria, Cubozoa) is a progression of the scyphozoan multiplex statolith. It is therefore suggested that the Cubozoa are derived from a scyphozoan ancestor and are a highly developed taxa within the Rhopaliophora.