Michael O. Angelidis

Geochemical Study of Coastal Sediments Influenced by River-Transported Pollution: Southern Evoikos Gulf, Greece

The impact of river-transported metal pollution on the metal distribution in coastal sediments was studied in Southern Evoikos Gulf, Greece, a marine area characterized by relatively strong tidal currents. The river Asopos, which flows into this part of the Gulf, acts as a recipient of industrial effluents generated in the river drainage basin, which hosts approximately 300 industries including chemical and metal processing plants. Several trace metals (namely Cd, Cr, Cu and Ni) were found enriched in the marine sediments near the river mouth. However, only Cd and to a lesser degree Cu were related to the river-transported industrial pollution. The high Cr and Ni concentrations were of natural origin, probably from the weathering of ultramaphic rocks, which are abundant in the drainage basin of the river Asopos.

Metals in Sediments of Rhodes Harbour, Greece

Abstract Metal concentrations (Cd, Cr, Cu, Fe, Mn, Pb and Zn) were determined in the 0.5 n HCl extractable fraction of surface sediments collected in Rhodes Harbour, Rhodes Island, Greece. The metals related to human activities (Cu, Pb and Zn) were found in relatively higher concentrations in the harbour sediments and in some cases showed important enrichment compared to the nonpolluted coastal sediments. The highest metal enhancement was found in the fine sediments of the Mandraki Harbour, which is located in the vicinity of the main sewage outfall of a densely populated area.

Anthropogenic metal contamination and sapropel imprints in deep Mediterranean sediments.

Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event S1.

Seasonal fluctuations of nutrients and pesticides in the basin of Evrotas river, Greece

Abstract Water and sediment samples from several stations along the Evrotas river, were collected for one year period, from August 1991 to August 1992, and were analysed for nutrients (Total N, NO3‐N and Total P) and pesticides. Higher nutrient concentrations were detected in the part of the river which is flowing through the plain of Sparta and is receiving industrial and domestic effluents, as well as the runoff from the agricultural land of the area. The industrial effluents (orange juice plants) and the agricultural land runoff, seem to play the major role during winter and spring, while the discharge of domestic septage (cesspools contents) in the reduced water flow, appears to be an important source of nutrient pollution during summer. In the water and sediments of the river were detected the herbicides alachlor, atrazine, amitrol and simazine, the insecticides azinphos ethyl, carbofuran, diazinon, dicofol, endosulfan, fenlhion, methyl parathion, as well as the fungicide captan. In the river water, ...

Metal concentrations and metallothionein levels in Mytilus galloprovincialis from Elefsis bay (Saronikos gulf, Greece)

Spatial and temporal variability of Cd, Cu, Cr, Ni, Zn, Fe and Mn and metallothionein (MT) concentrations were determined in mussels Mytilus galloprovincialis from Elefsis bay (Saronikos gulf, Greece). Higher concentrations of both metal concentrations and MTs were recorded in mussels inhabiting industrial locations (steelworks and shipyard), indicating a markedly higher metal bioavailability. However at these sites, located at the eastern part of the bay, mussel metal concentrations were not always correlated with both seawater metal concentrations and MTs possibly due to different time scales of integration of the metal sources into mussels and/or the participation of other metal regulatory mechanisms except MT induction. The pattern of the temporal variation of mussel metal concentrations and the MT levels was similar among stations with higher values during the winter–spring season and lower during the summer–autumn period. The inverse relationship of flesh condition index with mussel metal concentrations was attributed to the influence of mussel annual reproductive cycle.

Pollution mechanisms in a Ramsar wetland: delta of the River Evros, Greece

The pollution mechanisms affecting the protected wetland of the river Evros delta, were investigated during an one year survey (1992–1993). The eastern part of the wetland was mainly influenced by river transported pollution which is generated in the greater catchment basin of the river Evros, in Bulgaria, Turkey and Greece. In this part of the wetland, the highest concentrations of organic matter were found during summer, but nutrients concentrations increased during the early winter months. Nitrogen concentrations remained high throughout spring but SRP concentrations decreased considerably during the same period. In the western part of the wetland, the watercourses were mainly influenced by local activities (agriculture and animal breeding) but pollutant concentrations were lower than in the river stations. These preliminary results indicate that river transported pollution is the major factor for the quality degradation of the wetlands waters.

Impact of human activities on the quality of river water: The case of Evrotas River catchment basin, Greece

The impact of point (domestic and industrial effluents) and non-point (agricultural land runoff) pollution sources on the quality of the receiving waters of the Evrotas River (Laconia, Greece) was investigated during a monitoring study from August 1991 to August 1992. The part of the river which was located near the city of Sparta was seasonally influenced by the discharge of effluents from orange juice plants (operating during winter) and by the discharge of septage for the emptying of cesspools which are serving part of the city. The low dilution of incoming pollutants (septage) during the low water flow in summer lead to the decreasing self-purification capacity of the river and the development of septicity conditions in some of its parts. In the vicinity of intensively cultivated areas, the high concentrations of nitrogen and phosphorus which were detected in the river water during winter and spring may be partly attributed to the leaching of the applied fertilizers because of nirogen mobilization and soil erosion, following the seasons precipitations. The protection of the Evrotas River water Quality must therefore include adequate treatment of the septage produced in the area, as well as the construction of wastewater treatment plants for the major industries of the area. The non-point pollution could be controlled by the restoration of the Evrotas riparian vegetation, together with a more rational use of fertilizers in the area.

Spatial and temporal variability of composition of urban effluents in the island of Lesvos, Greece

The spatial and temporal variability in the composition of effluents of the coastal town of Mytilene, island of Lesvos, Greece, was investigated in 8 sewers of the town. Differences were found in the quality of effluents between the old and new parts of the town and were attributed mainly to the different design and construction of the sewers, as well as to the occasional discharge of septage into the sewerage network in parts of the town. During summer the population and water consumption increase, leading to partial dilution of the organic load. However, in the same period (July), the concentrations of dissolved Zn and particulate Pb were enriched. The reasons for such an increase are not clear. At present the seasonal metal peaks (Pb and Zn) are attributed to the increased traffic (Pb and Zn) and to increased corrosion under the prevailing weather conditions of the water supply network, which includes a very large number of galvanized storage tanks (Zn).

Nutrient removal using reed bed systems in Greece

Abstract Nutrient removal was studied in a pilot plant of reeds (Phragmites sp.) planted on soil and on gravelbed, and fed with the biologically treated domestic sewage of the city of Sparta, Greece. Substantial removal of the incoming nitrogen load was achieved through combined nitrification ‐ denitrification processes, but only small removal of phosphorus was observed. The reed system on gravel reached better nitrification rates, while denitrification was higher in the reed system grown on soil bed. However, the nutrient removal capability of both systems was seriously reduced when the influent ammonia load was increased. The reed bed system exhibited seasonal variations in their nutrient removal capacity, with the highest removal rates observed during summer and early autumn.