In this study, it was aimed to determine the heavy metal pollution and the factors causing this pollution in the water and sediment of the Bartın River during rainy and dry periods. Concentrations of Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn, As and some other metals in water and sediment samples collected from 4 different points during rainy and dry periods were investigated. It has been determined that both natural sources (soil erosion) and anthropogenic sources (runoff in urban and agricultural areas) affect metal concentrations in water and sediment during the rainy period. Heavy metal accumulation was less at the point with the least water depth (≈ 2 m). Higher concentrations were determined at the point where soil transport was highest during the rainy period. Since EF values of As, Pb, Zn and Li were greater than two in both periods, it was determined that they were affected by anthropogenic sources (wastewater discharges, agricultural and urban activities). EF values less than one showed that Co, Cr, Ba, Ni, Mn were related to lithogenic actions and riverbank runoff. Non-carcinogenic effects caused by metals did not pose a risk to adults and children.

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Atmospheric concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) compounds were investigated at three different regions of Istanbul which reflect urban, urban/industrial, and sub-urban characteristics. Air samples were collected simultaneously for both gaseous and particulate phases using high volume samplers on monthly time intervals from May 2011 to October 2012. The highest concentrations (3,056 fg/m(3) and 156 fg I-TEQ/m(3)) were observed at the sampling site that reflects traffic, residential, and industrial emission source characteristics, while the lowest concentrations (829 fg/m(3) and 38 fg I-TEQ/m(3)) were observed at the sampling point which is far away from centrum and reflects sub-urban characteristics. Concentrations of PCDD congeners were, in general, found to be higher than PCDF congeners, and OCDD, 1,2,3,4,6,7,8-HpCDD/F, and OCDF congeners were recorded to be the most abundant congeners. Winter season concentrations were also found to be higher especially in particulate phase. As a result, combustion processes such as motor vehicles and residential heating equipment were thought to be the principal sources of emissions of PCDD/F compounds when both congener profiles and seasonal variations are considered. Basic statistical evaluation of the data resembled high degree of inverse correlations between PCDD/F concentrations and UV and solar radiation.

The design and operational parameters of an activated sludge system were analyzed treating the municipal wastewaters in Istanbul. The design methods of ATV131, Metcalf & Eddy together with model simulations were compared with actual plant operational data. The activated sludge model parameters were determined using 3-month dynamic data for the biological nutrient removal plant. The ATV131 method yielded closer sludge production, total oxygen requirement and effluent nitrogen levels to the real plant after adopting correct influent chemical oxygen demand (COD) fractionation. The enhanced biological phosphorus removal (EBPR) could not easily be predicted with ATV131 method due to low volatile fatty acids (VFA) potential.

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