Coşkun Yurteri

Land-based sources of pollution along the black sea coast of Turkey: Concentrations and annual loads to the black sea

Abstract Concentrations of inorganic pollutants, pesticides and PCBs were measured in 42 sources including rivers, streams, and industrial and domestic discharge points along the Turkish Black Sea coast in three seasons of the year 1993. The measured concentrations were compared with water quality standards currently effective in Turkey in order to determine the levels of pollution in the rivers and streams. Concentrations were also combined with the water discharge data to determine annual loads of pollutants discharged from each source into the Black Sea. Concentrations of measured parameters were much higher in domestic and industrial discharges, as expected. Most of the rivers and streams were polluted with organic material, nitrogen and phosphorous species due to discharges of untreated domestic wastes into these streams. Metal concentrations measured in the rivers and streams were fairly low due to the lack of extensive industrialization in the drainage areas of the streams. Some of the small streams, including the Neyren, Kilimli, Zafir and Tabakhane streams, are heavily polluted and were identified as sources having the potential to generate hot spots along the coast. Annually, a total of 39.700 tons of nitrogen, 3.700 tons of phosphorous, 15 tons of Cd, 340 tons of Cu, 60 tons of Pb, 1.200 tons of Zn, 12 tons of heptachlor, 11 tons of aldrin, 31 tons of dieldrin, 180 tons of endrin and 500 tons of DDT are discharged from Turkish sources into the Black Sea. Except for trace metals, rivers and streams dominate the flux of pollutants. Large industries along the coast that discharge their wastes directly to the Black Sea account for a significant fraction of the annual metal discharges. Pesticides and PCBs were detected in most of the sources included in the study indicating their illegal use in agriculture. The Sakarya river was the most important source of pesticides.

Evaluation of eutrophication control strategies for the Keban Dam reservoir

Abstract The reservoir of the Keban Dam in eastern Anatolia is a very deep and large water body subject to significant seasonal water level fluctuations within a given hydrological year. At the present time, different sections of the reservoir have different trophic status and the upper portion of the reservoir, in particular, is eutrophic. In this regard, there is a need for the assessment of alternative strategies to be implemented for phosphorus and thus eutrophication control in this segment of the reservoir. In this study, mathematical modeling techniques are used to compare various alternatives in terms of their relative effectiveness for phosphorus control. With this intention, a two dimensional depth-averaged hydrodynamic model and a three-dimensional compartmental water quality model are coupled to represent the complex water body dynamics prevailing in the reservoir. After calibration and verification, the coupled model was used to simulate dissolved oxygen and euphotic chlorophyll-a concentrations under different scenario conditions corresponding to various strategies proposed for phosphorus control. The modelling effort has yielded valuable information that can be used by decision makers for the evaluation of different management alternatives including reduction of the phosphorus load coming from point as well as diffuse sources within the catchment area, use of baffles and construction of pre-dam structures.

Management strategies for the lower Seyhan catchment

Abstract The Seyhan river has a total catchment area of 20, 731 km2 with major pollution sources located downstream of the Seyhan Dam in Adana. The so-called Lower Seyhan, is under the threat of not only domestic and industrial wastewater discharges originating from the metropolitan area of Adana, but also agricultural wastes of the fertile Cukurova Plain. In this study, the present and future water quality characteristics of the Lower Seyhan have been investigated by means of a mathematical modelling study based on actual field data as well as in-situ water quality measurements. The model of choice was the QUAL2EU. The behaviour of the Lower Seyhan was studied under different pollution control scenarios in order to develop plausible water quality management strategies for the target year of 2010. As a result of these studies, two alternative systems were proposed for the management of the wastewater sources within the Lower Seyhan catchment. Alternative wastewater treatment plant designs and their cost implications were evaluated by means of the CAPDET-PC software package. A user-charging scheme and an optimisation model that can be used for demonstrating the economic viability of the proposed systems were also developed for obtaining a cost-optimum management policy for both municipalities and industrial establishments of the area.

Local Air Quality Impacts due to Downwash Around Thermal Power Plants: Numerical Simulations of the Effect of Building Orientation

One of the primary adverse environmental impacts associated with power generation facilities and in particular thermal power plants is local air quality. When these plants are operated at inland areas the dry type cooling towers used may significantly increase ambient concentrations of air pollutants due to the building downwash effect. When one or more buildings in the vicinity of a point source interrupt wind flow, an area of turbulence known as a building wake is created. Pollutants emitted from relatively low level sources can be caught in this turbulence affecting their dispersion. In spite of the fact that natural gas-fired combined-cycle power plants have lower air emission levels compared to other power plants using alternative fossil fuel, they can still create significant local air pollution problems. In this paper, local air quality impacts of a natural gas-fired combined-cycle power plant located in a coastal area are compared with those of another natural gas-fired combined-cycle power plant having identical air emissions but located in an inland area taking into account differences in topography and meteorology. Additionally, a series of scenarios for the inland site have been envisaged to illustrate the importance of plant lay-out configurations paying particular attention to the building downwash effect. Model results showed that different geometrical configurations of the stacks and cooling towers will cause remarkable differences in ambient air pollutant concentrations; thus it is concluded that when selecting a plant site, a detailed site-specific investigation should be conducted in order to achieve the least possible ambient air pollution concentrations with the given emissions.

A comparative evaluation of different approaches for assessing soil acidification impacts

Abstract Long‐term impacts of acidic depositions on soils can be predicted with coupled applications of acid deposition models and approaches to assess soil acidification. Soil acidification assessment can be achieved by using the following approaches: Mechanistic modelling Experimental acid buffering capacity (ABC) method Qualitative evaluations The mechanistic modelling approach adopted in this study utilises predicted acid deposition rates and soil properties as well as dominant soil mechanisms including utilisation, immobilization, nitrification, dissociation, association, carbonate weathering, silicate weathering, aluminium hydroxide disintegration, and cation exchange. The experimental ABC method, on the other hand, was based on titration curves obtained by adding different dilutions of H2SO4 to known quantities of soil samples. The sensitivities of the soil samples to acidification were also evaluated using a qualitative approach based on the pH and cation exchange capacity (CEC). A comparative eva...

Modelling Plume Rise and Dispersion of Power Plant Flue Gases Discharged Through Cooling Towers

Conventionally, treated flue gases of fossil-fueled thermal power plants are discharged through specially designed stacks in order to increase atmospheric dispersion. One of the innovative technologies involves the discharge through cooling towers instead of conventional tall stacks. The so-called “cooling tower discharge” (CTD) technology has proven to provide better dispersion of the power plant plume in the atmosphere (Schatzmann et al., 1984; Glamse et al., 1989; Ernst et al., 1986). Owing to its natural buoyancy and large heat content, the cooling tower plume mixed with the treated flue gas reaches considerably greater heights in the atmosphere. The CTD plume can even penetrate through the inversion layers (Ernst et al., 1986). The CTD technology, therefore lead a considerable decrease in the GLC values of pollutants by providing a better dispersion in the atmosphere (Ernst et al., 1986; Schatzmann et al., 1987).

Assessment of soil acidification due to a natural gas‐fired power plant by using two different approaches

Potential soil acidification impacts of a proposed natural gas‐fired combined cycle power plant were assessed using an integrated approach coupling an atmospheric deposition model with soil acidification quantification. The deposition model was used to estimate the rates of nitrogen oxide (NOx) deposition on the air‐soil boundary. The expected changes in the soil column were then predicted by utilizing mechanistic and experimental methods, and the number of years required to reach critical pH values were predicted using the two methods mentioned above under different rates of acidic deposition. The number of years predicted by the mechanistic modeling approach was lower for all soils exhibiting calcareous character.

Use of the Ames test in evaluating various natural waters in the vicinity of Ankara

In this study, we have evaluated various surface water supplies near the city of Ankara in terms of their potentials to yield mutagenic compounds upon chlorination. With this intention, raw water samples were chlorinated and then subjected to the “Ames Salmonella Mutagenicity Test” (ASMT). The observed ASMT results indicated a moderate potential for the formation of mutagenic compounds. Relationships between mutagenicity and selected surrogate water‐quality parameters were also examined. Mutagenicity displayed a generally increasing trend with quality parameters reflecting the background organic content.