Effects of light, temperature, nutrients and salinity on the growth of Cylindrotheca closterium (Ehrenberg) Reimann & J. Lewin, 1964 species isolated from Izmir Bay

WOS:000605750600006Cylindrotheca closterium is one of the diatom species that is dominant particularly in spring and summer in Izmir Bay and Aegean Sea. in this study, growth kinetics of Cylindrotheca closterium have been studied under different temperature, light intensity, nutrient concentrations and salinity conditions. Initially, temperature-light experiments were carried out and optimum temperature is determined to be 18 degrees C for this species. Obtained results at 18 degrees C are mu(max) = 1.97 +/- 0.167 d(-1) for the maximum specific growth rate and K-I = 0.048 +/- 0.028 for the half saturation constant. Then, six light intensities (0.9, 0.88, 0.74, 0.46, 0.2, 0.07 *100 mu mol photon/m(2)s) and seven salinity concentrations (5, 10, 15, 20, 25, 30 and 35 %) were investigated on the growth rate of Cylindrotheca closterium under optimum temperature. The specific growth rate has been calculated to be 2.012 d(-1) at 15 % salinity which is determined to be the optimum concentration. Exponential growth rates are obtained in semi-batch culture by measuring Chl a values and corresponded nutrient concentrations which are statistically valid (p<0,05) in regard to Monod equation (mu = mu(max)*S/K-S+S) and mu(max) values, a parameter of Monod equation, are calculated for different concentrations of ammonium, nitrate, reactive phosphate and reactive silica are 2.48 +/- 0.61 d(-1), 1.92 +/- 0.3 d(-1), 2.1 +/- 0.05 d(-1) and 1.97 +/- 0.20 d(-1), respectively. K-S values, which are another parameter of Monod equation, that are obtained for each nutrient are 17.84 +/- 14.4 mu M NH4+-N, 27.3 +/- 19.04 mu M NO3--N, 0.25 +/- 0.04 mu M PO4-P and 0.3 +/- 0.24 mu M Si, respectively. As a result of global warming, temperature is expected to be risen 6 degrees C in 2100 (Hallegraeff, 2010). The impacts of this increase on the growth rate of Cylindrotheca closterium species in Izmir Bay is calculated, considering this scenario. Nitrogen is determined to be the only restricting compound that inhibits growth during 52 weeks by a study that is conducted by Sunlu vd., (2007). Consequently, the growth rate of the species didn't decline under 1.5 d(-1) during this period of time

A survey of metal concentrations in marine sediment cores in the vicinity of an old mercury-mining area in Karaburun, Aegean Sea

WOS: 000401566600058PubMed ID: 28405925The aim of this study was to assess the historical trends of metal concentrations in coastal sediments in the vicinity of an inactive mining area, find background values and contamination levels of metals around the Karaburun peninsula, and then search for other sources of mercury in marine sediment cores using multivariate statistical analysis and report the potential ecological risks from that metal contamination. Surface sediment samples were taken from seven stations. Water depths were less than 20 m (coastal area) at stations KB07 and KB08. The depths at stations KB01, KB02, and KB03 were between 20 and 40 m, and stations KB05 and KB06 were more than 40 m (open area). In surface sediments at depths between 20 and 40 m, Mo, Cu, Pb, Zn, Ni, Co, Fe, Cd, Ti, Zr, Sn, As, Y, and Hg levels revealed higher contamination factors (C-f) compared to those of the coastal and open areas. Also, sediment samples were taken for historical records at stations KB01 and KB02 for 2012. Metal concentrations of Cu, Zn, Ni, Co, As, Sb, Cr, Ba, Ti, Al, and Hg in the sediment core samples were significantly higher during the Holocene (similar to 5700 BC to 2000 B.C.) and Medieval Warm periods (similar to 1000 A.D. to 1400 A.D.) and tended to decrease towards the Little Ice Age (2200 B.C. to the birth of Jesus Christ). Background concentration of Hg in sediment was found as 1.67 mu g/g around the Karaburun peninsula. Average EF values higher than 20 were identified for As, Hg, Sb, and Ca. Ni and Hg levels were found above the PEL values. It was determined that the accumulation effect of Hg coming from the mafic rocks due to erosion in the marine environment was higher than that of Hg coming from the mine. The factor analyses showed an association between Hg, Ni, and Co. This reveals the importance of the contribution of mafic rocks reaching the marine environment by wave erosion. According to the factor analyses, high concentrations of Pb, Zn, Cd, As, Sb, Ba, Ti, and Zr were detected in the lithogenic sources.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111Y311]; Ege University Scientific Research ProjectEge University [2012/BIL/033]This work was financially supported in the framework of a research project by the The Scientific and Technological Research Council of Turkey (TUBITAK, number of 111Y311) and Ege University Scientific Research Project (2012/BIL/033)

Determination of sedimentation rates in Izmir Bay using Pb-210 radionuclide

WOS: 000417222800015In this study, using the constant rate of supply model, sedimentation rates of Izmir Bay were calculated and discussed. For this purpose, eight sediment cores were collected from inner part of the bay and sedimentation rates were calculated from vertical distribution of Pb-210. Pb-210 activities were determined indirectly from Po-210 activities. Sedimentation rates ranged from 0.10 to 0.52 cm/year. The highest sedimentation rates were determined in stations close to the Poligon stream. It was concluded that main transporting mechanism for sediments is river and streams in the area. In addition, sediment cores taken from the harbor were mixed due to bioturbation, water circulation and/or other factors

Seasonal and spatial variations of ecological risk from potential toxic elements in the southern littoral zone of Izmir Inner Gulf, Turkey

This study aims to investigate the ecological risk level of potentially toxic elements (PTEs) in Izmir Inner Gulf. Samples were taken from 16 stations selected in the southern littoral zone of the gulf for four seasons (winter, spring, summer, and autumn). Multi-element, total organic carbon, chlorophyll-a, biogenic silica and carbonate analyses were carried out. To determine contamination level and ecological risks, some indices (enrichment factor, modified hazard quotient and potential risk analysis, toxic risk index, etc.) were calculated. Mo and Pb show significant anthropogenic enrichment in the inner gulf. These are followed by Cu, Cd, and Zn with moderate accumulation. Risk assessment indices point out that Ni, Cr, and Cd have a serious potential to create risk for ecosystem, and these are followed by As, Hg, Pb, Zn, and Cu. According to the spatial distribution, land use maps, and factor analysis, the Cd, Zn, and Cr increases are localized at the mouth of the Poligon Stream. Pb and Cu accumulate at the mouth of four large streams feeding the eastern part of the gulf. Pb and Cu enrichment is associated with traffic and industrial discharges. While one of the sources of Hg is anthropogenic, another source is eutrophication resulting from benthic and planktonic diatom blooms. While Fe and Mn are added to the gulf via rivers as a result of rock and soil erosion, another source is sediment. Cr, As, and Ni come from anthropogenic and lithogenic sources and immobilized in sediment. CO3-2 source is marine (biogenic) and dilutes other immobilized PTEs. It is understood that the peripheral stations rich in allochthonous organic carbon and the stations close to the central area rich in autochthonous organic carbon contribute to the carbon source in question.This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) within the scope of project 114Y419.Scientific and Technological Research Council of Turkey (TUBITAK) [114Y419

Biomonitoring, status and source risk assessment of polycyclic aromatic hydrocarbons (PAHs) using honeybees, pine tree leaves, and propolis

WOS: 000411846900017PubMed ID: 28772181In this study, to identify and quantify the sources of airborne polycyclic aromatic hydrocarbons (PAHs), we gathered honeybee, pine tree leaf, and propolis samples to serve as bioindicators from five stations in the village of "Bozkoy" in the Aliaga industrial district of Izmir (Turkey) during April-May 2014. The PAH concentrations which measured by gas chromatography (GC) varied from 261.18 to 553.33 mu g kg(-1) dry weight (dw) in honeybee samples, 138.57-853.67 mu g kg(-1) dw in pine leaf samples, and 798.61-2905.53 mu g kg(-1) dw in propolis samples. The total PAH concentrations can be ranked as follows: propolis > pine leaves > honeybees. The ring sequence pattern was 5 > 3 > 6 > 4 > 2 for honeybees, 5 > 3 > 4 > 6 > 2 for pine leaves, and 5 > 4 > 6 > 3 > 2 for propolis. The diagnostic ratios [fluoranthene/fluoranthene + pyrene], [indeno(1,2,3-c,d)pyrene/indeno(1,2,3-c,d)pyrene + benzo(g,h,i)perylene], and Ibenzo(a)anthraceneibenzo(a)anthracene + chrysenel indicate coal and biomass combustion to be the dominant PAH source in the study area. In biomonitoring studies of airborne PAHs based on honeybees, fluoranthene is considered to be a characteristic PAH compound. Distribution maps with different numbers of PAH rings among the sampling sites show the advantages of honeybee samples as indicators due to the honeybee's provision of a broader range of information with respect to heavier pollutants that are typically not in the gas or suspended phase for long periods of time. Our correlation, factor analysis, and principal components analysis (PCA) results indicate potential sources of PAH pollution in pine leaves and honeybees from airborne emissions, but we found propolis to be contaminated by PAHs due to the replacement of herbal sources of resins with synthetic gummy substances from paving materials (e.g., asphalt and tar leaks). (C) 2017 Elsevier Ltd. All rights reserved

Assessment of environmental applicability of TiO2 coated self-cleaning glass for photocatalytic degradation of estrone, 17 beta-estradiol and their byproducts

WOS: 000510854900005Optimization of photocatalytic degradation of two natural estrogenic compounds, estrone (El) and 17 beta-estradiol (17 beta-E2) in aqueous medium was performed on TiO2 coated Pilkington Activ (TM) self-cleaning glass as a novel approach to eliminate free nano-TiO2 releasing to the intended environment after treatment. the active glass was characterized by Atomic Force Microscopy (AFM), X-ray diffraction (XRD), and Raman spectroscopy to characterize the TiO2 nanoparticles. the main purposes were mineralization of target compounds in the treated water during the photocatalytic reaction and also to investigate the oxidation by products. Response Surface Methodology (RSM) has been applied to optimize the photocatalytic degradation by changing time, pH, and light intensity as effective factors. According to the results, time was the more effective parameter. the maximum efficiency degradation was achieved in alkaline media. Due to interactive effects between variable factors, 1 mg/L aqueous solution of El and 17 beta-E2 in water was totally decomposed by TiO2 photocatalyzed reactions under UV-C irradiation of 10.08 W/m(2) for 52.49 min at pH 9.42. Results of GC-MS analysis were introduced 17-deoxy Estrone and 2-Hydroxyestradiol as intermediate products for El and 17 beta-E2, respectively. All of the peaks finally disappeared after 170 min. Optimized conditions were applied for real sample of wastewater, presenting 30.40% and 56.84% in the efficiency degradation of El and 17 beta-E2, respectively.Ege University Scientific Research (BAP)Ege University [2017/SUF/014]This study is partially funded by Ege University Scientific Research (BAP) (Project No.: 2017/SUF/014). Authors acknowledge Dr. Ozan Unsalan (Ege University, Department of Physics) for help with the analysis of Raman spectrums. Golnar Matin thank Prof. Yury Gogotsi (A.J. Drexel Nanotechnology Institute, Drexel University) for his kind comments and suggestions on characterization of TiO2 nanocrystals coated on the glass

Abatement efficiency and fate of EPA-Listed PAHs in aqueous medium under simulated solar and UV-C irradiations, and combined process with TiO2 and H2O2

WOS:000605750200003Photolytic degradation of dissolved compounds of 16 EPA-Listed PAHs in aqueous medium, exposed to ultraviolet/ titanium dioxide (UV-C/TiO2), xenon light/ titanium dioxide (Xe/TiO2), xenon light/ hydrogen peroxide (Xe/H2O2) and ultraviolet/ hydrogen peroxide (UV-C/H2O2) was studied. The compounds which detected above detection limit of applied analytical method and instrument include: naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorene (Flu), fluoranthene (Fln) and pyrene (Pyr) survived. A time-course experiment (0, 1, 2, 5, 12 min) was performed to determine the fate of PAHs profile along treatments. After accomplishment of the removal process Sigma(6) PAHs ranked as follow: UV-C/TiO2 > Xe/TiO2 > UV-C > Xe > Xe/H2O2, and UV-C /H2O2 with estimated values of 76.38, 23.02, 22.55, 2.78, 0.00 and 0.00% of the concentration values at the beginning of the treatment, respectively. High efficiency of Xe/H2O2 treatment process (100.00%) at the end of treatment and the structure of residual PAHs which changed to the lighter compounds (2,3-ringed PAHs) before accomplishment of the removal process were proven. Generally, low resistance of Fln to all treatment conditions was observed. Total removal of Nap was considered to be a characteristic PAH compound for completion of the removal of PAHs. Mutate of parent PAH compounds and intermediates were analyzed by gas chromatography-mass spectrometry (GC-MS) and the results suggest the evaluating the toxicity of the treated water due to by-product formation concerns.Ege University Scientific Research (BAP)Ege University [2017/SUF/014]This study was partially funded by Ege University Scientific Research (BAP) (Project No.: 2017/SUF/014). Authors acknowledge Dr. Ozan Unsalan (Ege University, Department of Physics) for his help with the analysis of Raman spectra. Navid Kargar and Golnar Matin thank Prof. Yury Gogotsi (A.J. Drexel Nanotechnology Institute, Drexel University) for his useful comments and suggestions on characterization of TiO2 nanocrystals