Global NEST Journal

The determination of organotin compounds (OTCs) in environmental matrices has been subject to great scientific attention during last years, as the accuracy and sensitivity of analytical methods need to be improved in order to be able to detect the compounds of interest in a complex matrix such as sediment. The European Union Water Framework Directive (2013/39/EU) sets very restrictive environmental quality standards for 45 priority substances and other pollutants, including OTCs. Therefore, it is necessary to develop analytical methods in compliance with the environmental quality standard (EQSs) proposed to protect the aquatic environment and human beings. So far various analytical procedures have been used, including gas chromatographic analyses. Most of these methods comprise different steps such as extraction, derivatisation, clean up and the use of several sophisticated instrumentations, as well. Among them the conversion of tributyltin into Sn to allow its determination by Atomic Absorption Spectrometry or Anodic Stripping Voltammetry (AVS) has also been attempted. A great number of studies have been performed on OTCs analysis in marine sediment. However, the only review available in literature discussing the upgrades of analytical methods is dated back to 1997. We reviewed the analytical procedures and discussed them comparatively in order to identify the current state-of-the-art in OTCs detection. Finally, environmental concerns about OTCs were discussed.

In this study, chemical composition of coarse (PM2.5-10) and fine (PM2.5) aerosols and their seasonal characteristics was used to investigate factors affecting seasonal variations in concentrations of species. Concentrations of 17 trace elements and SO42- were determined in coarse and fine aerosol samples collected at a high altitude (1115 m above sea level) site (Torul, 40°32’34”N 39°16’57”E) between March 2011 to November 2012 on the Eastern Black Sea region of Turkey. The samples were analyzed by energy dispersive x-ray fluorescence (EDXRF) using an Oxford ED–2000 Spectrometer. Measured concentrations varied between approximately 0.40 ± 0.7 ng m-3 for As and 2070 ± 1270 ng m-3 for SO42-. Soil-derived elements, Al, Si, K, Ca, Ti, V and Fe, had higher concentrations in the coarse fraction as expected. The results indicated that concentrations of elements showed well-defined seasonal variations. Crustal elements showed higher concentration in summer. Na, which is an element generally associated with sea salt had also higher concentrations in summer season, suggesting a strong crustal contribution to Na concentration at our station. Anthropogenic elements As, Zn, Pb and Cr had comparable concentrations in both seasons. Cu, Ni, and V, had higher concentrations in winter season due to sources close to sampling point. Crustal enrichment factors of Ni, Cu, Cr, As, Pb, Zn and SO42- varied between 12 for Ni and 800 for SO42-. Upper atmospheric flow climatology showed that most frequent flow direction was the sector between West and North, indicating the regions between these wind sectors are the potential source regions for the observed levels of species.

The method of Levenberg-Marquardt learning algorithm was investigated for estimating tropospheric ozone concentration. The Levenberg-Marquardt learning algorithm has 12 input neurons (6 pollutants and 6 meteorological variables), 28 neurons in the hidden layer, and 1 output neuron for the Ozone (O3) estimate. The Multilayer Perceptron Model (MLP) performance was found to make good predictions with the mean square error (MSE) less than 1 µg/m3 (0.002 µg/m3). In addition, the correlation coefficient ranges from 0.74 to 0.95 in The Levenberg-Marquardt learning. The Levenberg-Marquardt learning algorithm that a multilayer perception method of Artificial Neural Network (ANN) has performed well and an effective approach for predicting tropospheric ozone. Ozone concentration was influenced predominantly by the nitrogen oxide (NOx, NO2, NO), SO2 and temperature. The model did not predict solar radiation to ozone with sufficient accuracy.

One of the most important environmental problems is municipal solid waste management (MSWM) as a result of the rapid rise in waste generation due to industrialization, economic development, urbanization, and rapid population growth in Turkey. The collection, transportation, and disposal of solid waste are conducted by municipal authorities of Turkey. The waste management problem is getting more serious due to some reasons such as lack of enforcement of regulations, weak technical and financial resources, poor infrastructure, insufficient policies and deficiency of political priorities, poor coordination between authorities. Hence, despite the legislation, municipal solid wastes are managed in an unscientific manner by the municipalities. The SWOT analysis is a perfect tool to discover the possibilities and ways for successfully implementing the MSWM. In this study, SWOT analysis carried out both negative and positive concerns of MSWM. A successful strategic management has been identified from the SWOT analysis for the municipal solid wastes. Further, the study proposes options based on SWOT analysis approach to improve in available waste management practices that could also be adopted by other countries to decrease the adverse effect of MSW on human and environment health.