Operational Cost Comparison of Several Pre‐Treatment Techniques for OMW Treatment

Olive mill wastewaters (OMWs), which are known to have deep impacts on the receiving water bodies due to their high‐strength contents of organic materials and color, must be treated before discharge. For this reason; a number of research studies have been available in current literature related to the treatment of OMWs. However, no widely accepted treatment alternatives have been proposed yet. The common results of these studies suggest that OMWs must be pretreated prior to final purification processes. This study focuses on the comparison of alternative pre‐treatment processes in the aspect of chemical oxygen demand (COD) removal and costs of operation. Centrifuging, lime precipitation, acid cracking, and electrocoagulation processes were performed to compare removal efficiencies and operational costs. The COD removal efficiencies for centrifuging, lime precipitation, acid cracking, and electrocoagulation processes were determined to be 30.1, 24.1, 20.0, 53.7%, respectively, with operational costs being $0.30, $0.37, $1.42, and $11.60 per cubic meter of wastewater treated, respectively. The centrifuging process was concluded to be the most appropriate one according to the COD removal efficiency and cost of operation.     

Stochastically simulated blast-induced ground motion effects on nonlinear response of an industrial masonry chimney

This paper presents the dynamic response analysis of industrial masonry chimney subjected to artificially generated surface blast induced ground shock by using a three-dimensional finite element model. The effects of surface blast-induced ground shocks on nearby structures depend on the distance between the explosion centre and the structure, and charge weight. Blast-induced ground motions can be represented by power spectral density function and applied to each support point of the 3D finite element model of the industrial masonry system. In this study, a parametric study is mainly conducted to estimate the effect of the blast-induced ground motions on the nonlinear response of a chimney type masonry structure. Therefore, the analysis was carried out for different values of the charge weights and distances from the charge center. The initial crack and propagation of the crack pattern at the base of the chimney were evaluated. Moreover, the maximum stresses and displacements through the height of the chimney were investigated. The results of the study underline that blast-induced ground motions effects should be considered to perform the non-linear dynamic analysis of masonry type chimney structures more accurately.     

Compatible ground-motion prediction equations for damping scaling factors and vertical-to-horizontal spectral amplitude ratios for the broader Europe region

In a companion article Akkar et al. (Bull Earthq Eng, doi:10.1007/s10518-013-9461-4, 2013a; Bull Earthq Eng, doi:10.1007/s10518-013-9508-6, 2013b) present a new ground-motion prediction equation (GMPE) for estimating 5 %-damped horizontal pseudo-acceleration spectral (PSA) ordinates for shallow active crustal regions in Europe and the Middle East. This study provides a supplementary viscous damping model to modify 5 %-damped horizontal spectral ordinates of Akkar et al. (Bull Earthq Eng, doi:10.1007/s10518-013-9461-4 2013a; Bull Earthq Eng, doi:10.1007/s10518-013-9508-6, 2013b) for damping ratios ranging from 1 to 50 %. The paper also presents another damping model for scaling 5 %-damped vertical spectral ordinates that can be estimated from the vertical-to-horizontal (V/H) spectral ratio GMPE that is also developed within the context of this study. For consistency in engineering applications, the horizontal and vertical damping models cover the same damping ratios as noted above. The article concludes by introducing period-dependent correlation coefficients to compute horizontal and vertical conditional mean spectra (Baker in J Struct Eng 137:322–331, 2011). The applicability range of the presented models is the same as of the horizontal GMPE proposed by Akkar et al. (Bull Earthq Eng, doi:10.1007/s10518-013-9461-4 2013a; Bull Earthq Eng, doi:10.1007/s10518-013-9508-6, 2013b): as for spectral periods $0.01 \hbox { s}\le \,\hbox {T}\le \,4\hbox { s}$ as well as PGA and PGV for V/H model; and in terms of seismological estimator parameters $4\le \hbox {M}_\mathrm{w} \le 8, \hbox { R} \le 200 \hbox { km}, 150\hbox { m/s}\le \hbox { V}_\mathrm{S30}\le $ 1,200 m/s, for reverse, normal and strike-slip faults. The source-to-site distance measures that can be used in the computations are epicentral $(\hbox {R}_\mathrm{epi})$ , hypocentral $(\hbox {R}_\mathrm{hyp})$ and Joyner–Boore $(\hbox {R}_\mathrm{JB})$ distances. The implementation of the proposed GMPEs will facilitate site-specific adjustments of the spectral amplitudes predicted from probabilistic seismic hazard assessment in Europe and the Middle East region. They can also help expressing the site-specific design ground motion in several formats. The consistency of the proposed models together with the Akkar et al. (Bull Earthq Eng, doi:10.1007/s10518-013-9461-4 2013a; Bull Earthq Eng, doi:10.1007/s10518-013-9508-6, 2013b) GMPE may be advantageous for future modifications in the ground-motion definition in Eurocode 8 (CEN in Eurocode 8, Design of structures for earthquake resistance—part 1: general rules, seismic actions and rules for buildings. European Standard NF EN 1998-1, Brussels, 2004).     

Using high resolution images and elevation data in classifying erosion risks of bare soil areas in the Hatila Valley Natural Protected Area, Turkey

Soil erosion is one of the most important environmental problems. In the case of small scale areas where soil properties and climate have relatively uniform characteristics, vegetation cover and topography (i.e. ground slope) are the main factors that affect the amount of soil erosion. Lack of vegetation cover on bare soil areas, including forest road side slopes, especially in mountainous regions with steep slopes, may significantly increase the erosion rate. Determining and classifying erosion risks in such areas can help preventing environmental impacts. In this study, remotely sensed data and elevation data were used to extract and classify bare soil erosion risk areas for a study area selected from Hatila Valley Natural Protected Area in northeastern Turkey. High resolution IKONOS imagery was used to apply land use classification in ERDAS Imagine 9.0. To generate erosion risk map of the bare soil areas, classified image was superimposed on top of slope map, generated based on a Digital Elevation Model (DEM) in ArcGIS 9.2. The results indicated that 1.43, 5.85, 34.62, 53.16, and 4.94% of the bare soil areas in the study area were under very low, low, medium, high, and very high erosion risks, respectively. The overall classification accuracy of 82.5% indicated the potential of the proposed methodology.     

The sources of metal contents in the shelf sediments from the Marmara Sea, Turkey

The shelf area is the largest morphological unit of the Marmara Sea and is subjected to increasing population, urbanization, and industrial activities. Metal contents (Al, Fe, Mn, Cu, Pb, Zn, Ni, Cr, Co and Hg) of the surface sediments from the shelf areas of the Marmara Sea generally do not indicate shelf-wide pollution. The variability of the metal contents of the shelf sediments is mainly governed by the geochemical differences in the northern and southern hinterlands. Northern shelf sediments contain lower values compared to those of the southern shelf, where higher Ni, Cr, Pb, Cu and Zn are derived from the rock formations and mineralized zones. However, besides from the natural high background in the southern shelf, some anthropogenic influences are evident from EF values of Pb, Zn and Cu, and also from their high mobility in the semi-isolated bay sediments. Anthropogenic influences are found to be limited at the confluence of Istanbul Strait in the northern shelf. However, suspended sediments along the shallow parts of the northern shelf were found to be enriched in Pb and Hg and to a lesser degree in Zn, reflecting anthropogenic inputs from Istanbul Metropolitan and possibly from the Black Sea via the Istanbul Strait.     

Water level changes in Lake Van,Turkey, during the past ca. 600 ka: climatic,volcanic and tectonic controls

Sediments of Lake Van, Turkey, preserve one of the most complete records of continental climate change in the Near East since the Middle Pleistocene. We used seismic reflection profiles to infer past changes in lake level and discuss potential causes related to changes in climate, volcanism, and regional tectonics since the formation of the lake ca. 600 ka ago. Lake Van’s water level ranged by as much as 600 m during the past ~600 ka. Five major lowstands occurred, at ~600, ~365–340, ~290–230, ~150–130 and ~30–14 ka. During Stage A, between about 600 and 230 ka, lake level changed dramatically, by hundreds of meters, but phases of low and high stands were separated by long time intervals. Changes in the lake level were more frequent during the past ~230 ka, but less dramatic, on the order of a few tens of meters. We identified period B1 as a time of stepwise transgressions between ~230 and 150 ka, followed by a short regression between ca. 150 and 130 ka. Lake level rose stepwise during period B2, until ~30 ka. During the past ~30 ka, a regression and a final transgression occurred, each lasting about 15 ka. The major lowstand periods in Lake Van occurred during glacial periods, suggesting climatic control on water level changes (i.e. greatly reduced precipitation led to lower lake levels). Although climate forcing was the dominant cause for dramatic water level changes in Lake Van, volcanic and tectonic forcing factors may have contributed as well. For instance, the number of distinct tephra layers, some several meters thick, increases dramatically in the uppermost ~100 m of the sediment record (i.e. the past ~230 ka), an interval that coincides largely with low-magnitude lake level fluctuations. Tectonic activity, highlighted by extensional and/or compressional faults across the basin margins, probably also affected the lake level of Lake Van in the past.     

Estimation of Crown Closure and Tree Density Using Landsat TM Satellite Images in Mixed Forest Stands

The objective of this study was to investigate the relationship between crown closure and tree density in mixed forest stands using Landsat Thematic Mapper (TM) reflectance values (TM 1- TM 5 and TM 7) and six vegetation indices (SR, DVI, SAVI, NDVI, TVI and NLI). In this study, multiple regression analysis was used to estimate the relationships between the crown closure and tree density (number of tree stems per hectare) using reflectance values and vegetation indices (VIs). The results demonstrated that the model that used SR and DVI had the best performances in terms of crown closure (R²?=?0.674) and the model that used the DVI and SAVI had the best performances in terms of tree density (R²?=?0.702). The regression model that used TM 1, TM 3 together with TM 4 showed the performances of the crown closure (R²?=?0.610) and the regression model that used TM 1 showed the performances of the tree density (0.613). Results obtained from this research show that vegetation indices (VIs) were a better predictor of crown closure and tree density than other TM bands.