Trace Element Patterns and Seasonal Variability of Dust Precipitation in a Low Polluted City – The Example of Karlsruhe/Germany

Urban areas of different land uses can be distinguished by their specific patterns of atmospheric dust and trace element precipitation. Dusts emitted from industrial areas with fossil fuel processing, for instance, are enriched in V, Ni and Co. Cluster analysis groups sampling sites based on their specific element patterns. The resulting groups correspond to the surrounding land use: Urban sampling sites were identified showing similar patterns of dust and trace element precipitation as a reference site; dusts of other urban sites were influenced by diffuse pollution (caused by non-point and dispersed pollution sources), or by specific industrial emissions. Cluster analysis was also used to characterize the chemical dust composition. Three clusters of typical element associations were distinguished. These clusters represent the dust matrix, diffuse urban pollution and pollution due to fossil fuel processing. Dust precipitation and chemical dust composition show seasonal variations. Dust precipitation and concentrations of trace elements in the precipitated dust are negatively correlated during the annual courses. The highest concentrations of trace elements occur during winter, whereas the highest precipitations of dust were found during summer. This finding stresses that both, precipitation and concentration have to be addressed for the environmental assessment of urban dusts.     

Simultaneous biological removal of endosulfan (alpha+beta) and nitrates from drinking waters using wheat straw as substrate

Nitrate and endosulfan (alpha+beta) removal was studied in an upflow biological denitrification reactor packed with wheat straw as carbon source and support particles for microorganisms. While almost complete nitrate elimination and between 65% and 70% endosulfan (alpha+beta) elimination occurred when the temperature was higher than 20 degrees C; below that value, nitrate removal efficiency decreased to about 10%. Nitrate, dissolved organic carbon (DOC), and endosulfan (alpha+beta) removal efficiencies decreased considerably at 1500 microg/l endosulfan concentration in the batch experiments. Although a high removal efficiency was observed for endosulfan (alpha+beta) and nitrate in the biological denitrification continuous reactor, the effluent water could not be used for drinking purpose because of the unacceptable levels of endosulfan (alpha+beta), colour and dissolved organic content. During the continuous study, 23.4% of the initial weight of wheat straw was lost and 24 g was consumed per gram of nitrogen removed. The results of the continuous study showed that 21.3% of the endosulfan removal was achieved by adsorption onto the wheat straw and 68.2% of the endosulfan removal occurred by biological activity and the remaining portion was detected in the effluent water.     

Oberflächennahe Rohstoffe und Öffentlichkeit

The public has been sensitized to the fact that due to the shortage of energy resources, mainly hydrocarbons, energy policy difficulties and the interrelated problems of nuclear energy, nuclear waste disposal and environmental protection, have developed. However, what is realized much less is the fact that mineral resources are also not available in unlimited amounts in some industrial nations, especially near-surface industrial minerals, whose prices are often very sensitive to transport costs. This can be explained only partly by geological conditions, but by limited access to the resources. By setting its goals too high, society risks in many respects the fulfillment of its desires for improving the standard of living.     

Automatic sorting of ichthyoplankton; Factors controlling plankton density in gradients of silica

Following isopycnic sedimentation in density gradients of colloidal silica (Ludox AM), zooplankton segregated into 3 broad bands of increasing density which included, respectively, fish eggs, invertebrates, and fish larvae. The zone of fish eggs was contaminated with Sagitta spp. and the zone of fish larvae was overlapped partially by mysids and euphausids. We have sought to minimize contamination through modifications of the silica gradients which might shift banding densities of the ichthyoplankton or of the contaminating invertebrates. Density shifts in fact occurred in different commercial formulations of silica sols and in gradients modified by small amounts of polymers, osmotica or charged small molecules. Sagitta were specifically shifted out of the zone of fish eggs by the addition, of 1% w/v dextran sulfate or in a silica sol composed of very small particles of silica (Nalcoag 1115). Fish larvae were shifted to higher densities by the addition of 1% w/v trimetaphosphate or 1% w/v dextran sulfate. Additions of 1% w/v polyvinyl alcohol, and of 10 mM glycine, and potassium phosphate had intermediate effects. The same banding densities of plankton in silica gradients were reached in less than 10 h at one gravity, independent of the immediate pretreatment of the sample.     

Solid waste management practices and review of recovery and recycling operations in Turkey

This paper provides a general overview of solid waste data and management practices employed in Turkey during the last decade. Municipal solid waste statistics and management practices including waste recovery and recycling initiatives have been evaluated. Detailed data on solid waste management practices including collection, recovery and disposal, together with the results of cost analyses, have been presented. Based on these evaluations basic cost estimations on collection and sorting of recyclable solid waste in Turkey have been provided. The results indicate that the household solid waste generation in Turkey, per capita, is around 0.6 kg/year, whereas municipal solid waste generation is close to 1 kg/year. The major constituents of municipal solid waste are organic in nature and approximately 1/4 of municipal solid waste is recyclable. Separate collection programmes for recyclable household waste by more than 60 municipalities, continuing in excess of 3 years, demonstrate solid evidence for public acceptance and continuing support from the citizens. Opinion polls indicate that more than 80% of the population in the project regions is ready and willing to participate in separate collection programmes. The analysis of output data of the Material Recovery Facilities shows that, although paper, including cardboard, is the main constituent, the composition of recyclable waste varies strongly by the source or the type of collection point.     

Evaluating factors influencing groundwater vulnerability to nitrate pollution: developing the potential of GIS

The 1991 EU Nitrate Directive was designed to reduce water pollution from agriculturally derived nitrates. England and Wales implemented this Directive by controlling agricultural activities within their most vulnerable areas termed Nitrate Vulnerable Zones. These were designated by identifying drinking water catchments (surface and groundwater), at risk from nitrate pollution. However, this method contravened the Nitrate Directive because it only protected drinking water and not all waters. In this paper, a GIS was used to identify all areas of groundwater vulnerable to nitrate pollution. This was achieved by constructing a model containing data on four characteristics: the quality of the water leaving the root zone of a piece of land; soil information; presence of low permeability superficial (drift) material; and aquifer properties. These were combined in a GIS and the various combinations converted into a measure of vulnerability using expert knowledge. Several model variants were produced using different estimates of the quality of the water leaving the root zone and contrasting methods of weighting the input data. When the final models were assessed all produced similar spatial patterns and, when verified by comparison with trend data derived from monitored nitrate concentrations, all the models were statistically significant predictors of groundwater nitrate concentrations. The best predictive model contained a model of nitrate leaching but no land use information, implying that changes in land use will not affect designations based upon this model. The relationship between nitrate levels and borehole intake depths was investigated since there was concern that the observed contrasts in nitrate levels between vulnerability categories might be reflecting differences in borehole intake depths and not actual vulnerability. However, this was not found to be statistically important. Our preferred model provides the basis for developing a new set of groundwater Nitrate Vulnerable Zones that should help England and Wales to comply with the EU Nitrate Directive.     

Point- and nonpoint-source pesticide contamination in the Zwester Ohm catchment, Germany

Reducing pesticide loads in surface waters implies identifying the pathways responsible for the pollution. The current study documents the pesticide contamination of the river Zwester Ohm, a 4917-ha catchment in Germany with 41% of the land used for crop production. Discharges and concentrations of 19 pesticides were measured continuously at three locations for 15 mo. The load detected at the outlet of the catchment amounted to 9048 g a.i. The losses represent 0.22% of the pesticides applied by the farmers. The contamination showed a seasonal pattern following the pesticide application times. The wastewater treatment plant system (WWTPS) in the catchment (two wastewater treatment plants [WWTP], 14 combined sewer overflows (CSO), four CSO tanks) emits during dry weather periods purified sewage and during storm events sewage mixed with stormwater runoff into the river. The contribution by the WWTPS to the pesticide load was defined as point-source pollution (PSP). The load was dominated by PSP with at least 77% of the total pollution. No significant interdependencies between intrinsic properties of the pesticides, hydrometeorological factors, and the loads occurring in the stream could be found. Therefore, it is not possible to predict PSP for other catchments based on the results from this study. Whereas 65% of the total load entered the river via the WWTP, a portion of 12% was attributed to the CSO. The study points out that the influence of CSO on PSP should be taken into account in future catchment studies in areas with comparable agricultural structure.