Cationic dye adsorption onto natural and synthetic zeolites in the presence of Cs+ and Sr2+ ions

Adsorption of diazine dye safranine O (SO) in the presence of Cs⁺ and Sr²⁺ ions was investigated onto natural and synthetic zeolites in order to predict competition of cationic organic species with their radionuclides, which are the main fission products released into the environment. Adsorption of SO was measured up to the 40th day and the surface-diffusion coefficients (D_s) were estimated by applying Nernst–Planck approximation based on a homogeneous-surface-diffusion model. The values of D_s were 10 times higher on natural zeolite than those of synthesized zeolite from fly ash (FA) under hydrothermal conditions. Similarly, distribution coefficients (K_D) were considerably higher on the clinoptilolite-type natural zeolite. The zeolitized product of FA is mainly composed of analcime and sodalite. SO adsorption on natural zeolite was not influenced by Cs⁺ and Sr²⁺ ions, but it decreased at high concentrations on synthetic zeolite. The higher influence of the Sr²⁺ ions on SO⁺ adsorption showed that they compete with each other for the same adsorption sites. These results suggested that natural zeolite cannot be used for remediation of wastewater polluted with Cs and Sr radionuclides in the presence of organic cations, whilst FA zeolite has a potential for Sr removal.     

Estimation of total sediment load concentration obtained by experimental study using artificial neural networks

Estimation of sediment concentration in rivers is very important for water resources projects planning and managements. The sediment concentration is generally determined from the direct measurement of sediment concentration of river or from sediment transport equations. Direct measurement is very expensive and cannot be conducted for all river gauge stations. However, sediment transport equations do not agree with each other and require many detailed data on the flow and sediment characteristics. The main purpose of the study is to establish an effective model which includes nonlinear relations between dependent (total sediment load concentration) and independent (bed slope, flow discharge, and sediment particle size) variables. In the present study, by performing 60 experiments for various independent data, dependent variables were obtained, because of the complexity of the phenomena, as a soft computing method artificial neural networks (ANNs) which is the powerful tool for input–output mapping is used. However, ANN model was compared with total sediment transport equations. The results show that ANN model is found to be significantly superior to total sediment transport equations.     

Monitoring forest structure at landscape level: a case study of Scots pine forest in NE Turkey

This study aims to investigate the change in spatial-temporal configuration of secondary forest succession and generate measurements for monitoring the changes in structural plant diversity in Yaln?zçam Scots pine forest in NE Turkey from 1972 to 2005. The successional stages were mapped using the combination of Geographic Information System (GIS), Global Positioning System (GPS), aerial photos and high resolution satellite images (IKONOS). Forest structure and its relationship with structural plant diversity along with its changes over time were characterized using FRAGSTATS. In terms of spatial configuration of seral stages, the total number of fragments increased from 572 to 735, and mean size of patch (MPS) decreased from 154.97 ha to 120.60 ha over 33 years. The situation resulted in forestation serving appropriate conditions for plant diversity in the area. As an overall change in study area, there was a net increase of 1823.3 ha forest during the period with an average annual forestation rate of 55.25 ha year^?1(0.4% per year). In conclusion, the study revealed that stand type maps of forest management plans in Turkey provide a great chance to monitor the changes in structural plant diversity over time. The study further contributes to the development of a framework for effective integration of biodiversity conservation into Multiple Use Forest Management (MUFM) plans using the successional stages as a critical mechanism.     

Atmospheric deposition of polycyclic aromatic hydrocarbons to Izmit Bay, Turkey

Wet deposition and dry deposition samples were collected in an urban/industrialized area of Izmit Bay, North-eastern Marmara Sea, Turkey, from September 2002 to July 2003. The samples were analyzed for sixteen polycyclic aromatic hydrocarbon (PAH) compounds by using HPLC-UV technique. Wet and dry deposition concentrations and fluxes of PAHs were determined. The results showed that PAH concentrations were high because of industrial processes, heavy traffic and residential areas next to the sampling site. Total dry deposition flux of the fifteen 3-6 ring PAHs was 8.30 microg m(-2)day(-1), with a range of 0.034-1.77 microg m(-2)day(-1). The total wet deposition flux of the fifteen 3-6 ring PAHs was 1716 microg m(-2) 11 month(-1), with a range of 10-440 microg m(-2) 11 month(-1). Significant seasonal differences were observed in both types of deposition samples. The winter fluxes of total PAHs were 1.5 and 2.5 times greater than those of the warm period for wet and dry deposition samples, respectively. Factor analysis of dry deposition samples and back trajectory analysis of wet deposition samples were also used to characterize and identify the PAH emission sources in this study.     

Genotoxic biomonitoring study of population residing in pesticide contaminated regions in Göksu Delta: micronucleus, chromosomal aberrations and sister chromatid exchanges

Pesticides are widely used throughout the world in agriculture to protect crops and in public health to control diseases. Nevertheless, exposure to pesticides represents a potential risk to humans. This paper describes a study of possible genetic damage in the people living in regions contaminated with complex mixture of pesticides in G?ksu Delta. In this study, used methods were chromosomal aberration (CA), sister chromatid exchange analysis (SCE) in the peripheral blood lymphocytes, and micronucleus (MN) assay in the buccal epithelial cells. In the present investigation, 32 affected subjects consist of 16 smoking and 16 non-smokings and an equal number of control subjects were assessed for genome damage. Micronucleus (MN), Broken egg (BE), Karyorrhexis (KR), Karyolysis (KL) and Binucleus (BN) frequencies were higher in affected subjects than in controls. Smoking had a statistically significant effect on the Micronucleus, Karyorrhexis and Binucleus frequencies for both the control and the exposed group. Also smoking and exposure affected the frequency of sister chromatid exchange and chromosomal aberrations compared with control groups.     

Genotoxic effects and molecular docking of 1,4-dioxane: combined protective effects of trans-resveratrol

Environmental Science and Pollution Research - In this study, the protective effects of trans-resveratrol (t-resv) against 1,4-dioxane-induced toxicity in meristematic cells were investigated. For...     

Disasters as an ideological strategy for governing neoliberal urban transformation in Turkey: insights from Izmir/Kadifekale

Since the turn of the twenty‐first century, Turkish cities have undergone large‐scale change through a process referred to as urban transformation, involving, notably, the demolition of inner‐city low‐income settlements. The official authorities and business circles have resorted to various forms of discourse to justify these projects, which have led to the deportation of a significant number of people to peripheral areas. The discourse of ‘natural disasters’, for example, suggests that urban transformation is necessary to protect people from some pending event. Probably the most effective application of this discourse has occurred in Izmir, where the risk posed by ‘landslides’ has played a critical role in the settlement demolitions conducted in the huge inner‐city neighbourhood of Kadifekale. By examining the case of Kadifekale, this paper provide some insights into how ‘natural disasters’ serve as a discourse with which to legitimise the neoliberal logic entrenched in the urban transformation process in Turkey.     

Functional regression on remote sensing data in oceanography

The aim of this study is to propose the use of a functional data analysis approach as an alternative to the classical statistical methods most commonly used in oceanography and water quality management. In particular we consider the prediction of total suspended solids (TSS) based on remote sensing (RS) data. For this purpose several functional linear regression models and classical non-functional regression models are applied to 10 years of RS data obtained from medium resolution imaging spectrometer sensor to predict the TSS concentration in the coastal zone of the Guadalquivir estuary. The results of functional and classical approaches are compared in terms of their mean square prediction error values and the superiority of the functional models is established. A simulation study has been designed in order to support these findings and to determine the best prediction model for the TSS parameter in more general contexts.     

Transformation of copper oxide and copper oxide nanoparticles in the soil and their accumulation by Hordeum sativum

Environmental Geochemistry and Health - In recent years, the study of the influence of nanoparticles (NPs) on the environment has attracted much interest as nanotechnology is becoming the key...     

An investigation of halogens in Izmit hazardous and clinical waste incinerator

In the combustion facilities, halogens (Cl, F, Br, I) should be considered with regard to the control of the compounds such as polychlorinated dibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF), halogenated polyaromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and volatile heavy metals formed as a result of incomplete combustion and caused adverse environmental effects. In this study halogens were observed in Izmit Hazardous and Clinical Waste Incinerator (IZAYDAS). Halogen contents of the combustion menu, flue gas, fly ash, bottom ash and filter cake were measured and their distributions in these exit streams were determined. Results showed that the major part of the halogens was partitioned to solid residues, i.e., bottom ash and filter cake which represents the removal by wet scrubbers. Fly ash and flue gas fractions of halogens were much lower due to the reduced formation of volatile compounds.