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Erzurum, Turkey

Korkmaz M.,Balikesir University | Ozmetin C.,Balikesir University | Fil B.A.,Atatiirk University | Ozmetin E.,Balikesir University | Yasar Y.,Balikesir University
Fresenius Environmental Bulletin | Year: 2013

The dyes and pigments have poisonous and mutagenic effect on humans and animals. In this study, the use of Bigadiç clinoptilolite (natural zeolite) as an adsorbent for removal of methyl violet dye from solutions was investigated. The dye adsorption experiments were carried out in batch mode as a function of pH (3-9), temperature (30-50 °C), ionic strength (0-0.1 M NaCl), clinoptilolite calcination temperature (0-200 °C), particle size (0-45; 180-425 urn) and solid-to-solution ratio (0.1-1.5g/50 mL). The dye adsorption capacity of the clinoptilolite mineral increased with high solution pH, high temperature, high salt concentration, low particle size and low solid-to-solution ratio. Clinoptilolite mineral provided higher adsorption capacity at calcination temperature of 50 °C. The equilibrium adsorption data fitted to the Langmuir isotherm rather than Freundlich model. The kinetic data could be explained by the pseudo second order model. Also, the kinetic data fitted to the intra particle diffusion model and this indicated that pore diffusion was rate controlling step in the applied batch process. Maximum adsorption capacity of the clinoptilolite mineral was calculated as 75.25 mg/g at pH 9. © by PSP. Source

Sonmez A.Y.,Kastamonu University | Hisar O.,Canakkale Onsekiz Mart University | Yanik T.,Atatiirk University
Fresenius Environmental Bulletin | Year: 2013

Heavy metals are among the most persistent of pollutants in aquatic systems due to their resistance to decomposition in nature. Four assessment methods (two pollution indexes and two fuzzy mathematical models - single-factor deciding and weighted average models) were used to check the level and characteristics of heavy metal pollution in the Karasů stream water. Several heavy metals such as Copper (Cu), Zinc (Zn), Manganese (Mn), Lead (Pb), Nickel (Ni), Cadmium (Cd) and Iron (Fe) were tested with these methods. A data set (12 months, total 180 measurements) was collected from 5 sampling points (A-E) of the River. The used criteria were classes, I-IV represents from clear to polluted one. Water quality was assessed as class IV from all water samples collected from the each station with single-factor index method. It was identified to be class IV from the samples of A, B, C and D stations, and class III from the sample of E station with the comprehensive index model. By using the fuzzy mathematical methods, the water quality were determined as classes of IV, IV, IV, II and II from the water samples of A, B, C, D and E stations respectively. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of water quality assessment. Therefore, these fuzzy mathematical methods might be quite convenient in evaluation of water pollution and classification considering the results of the present study. © by PSP. Source

Yazici K.,Karadeniz Technical University | Aptroot A.,ABL Herbarium G.v.d. | Aslan A.,Atatiirk University
Mycotaxon | Year: 2010

Three species of lichenized fungi - Arthonia calcarea, Buellia seauax, and Trapeliopsis gelatinosa - are reported here as new to Turkey. Buellia seauax and Trapeliopsis gelatinosa are also new to the Middle East. Distribution and substrate data are presented. Source

Demir M.,Eastern Anatolia Forestry Research Institute | Goktug T.H.,Adnan Menderes University | Bulut Y.,Atatiirk University
Fresenius Environmental Bulletin | Year: 2014

Water, as one of the crucial resources for the sustain-ability of vital activities of humans, is under a big pressure in the global context due to water scarcity, global warming and intense anthropogenic effects. In consequence of those changes on the environmental conditions, water resource management becomes crucial for the sustainabil-ity of human life. In this context, the paper focused on the Karasu River in Turkey, as one of the main tributaries of Euphrates crossing many provinces of Turkey, Syria, and Iraq. It has an international importance due to its geographical settings and is needed to be protected for the health and life of people living in those regions. Using this general information, the research on Karasu River has been designated to investigate and define anthropogenic factors effective on the pollution of the river in Erzurum Plain. This paper concluded with the proposal focused on alternative approaches for reducing levels of pollution. © by PSP. Source

Mindivan H.,Atatiirk University | Efe A.,Atatiirk University | Kayali E.S.,Technical University of Istanbul
Magnesium Technology | Year: 2014

Carbon nanotube (CNT) reinforced magnesium (Mg) matrix composite rod was successfully fabricated by mechanical ball milling followed by hot extrusion processes. CNTs used were multi-wall carbon nanotubes (MWCNTs). The starting Mg chips were ball-milled under argon atmosphere for 3 h to coat the surface of Mg chips with the pretreated MWCNTs. The CNT-coated Mg chips were then mixed with aluminum (Al) powder at the compositions of Mg-6 wt.% Al-x wt.% CNT (x = 0.5, 1, 2 and 4). The mixture was cold compacted and finally hot extruded. The distribution of CNTs was analyzed using a Scanning Electron Microscopy (SEM). Furthermore, the effect of CNTs and their amounts on the mechanical properties and corrosion behavior of the Mg composite were studied. Microstructural analysis revealed that the CNTs were well dispersed at the chip surfaces and were aligned with direction of the extrusion in the composites. As CNT content increased, chip size, density and electrical conductivity of the Mg composites decreased, a relatively constant value was obtained in the microhardness but a reduction was determined in compressive strength. While an increase up to 2 wt.% in CNT content reduced the corrosion rate of the composites, the corrosion rate increased at higher addition rates. Source

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