İbrahim İlker ÖZYİĞİT

Article | 2021 | Desalination and Water Treatment239

In this work, the experiments related to seasonal variations of phytoplankton composition and heavy metal contamination along with some water quality parameters were carried out throughout the channel, serving as a waterway between Lake Kucukcekmece and the Sea of Marmara. Considered as a Class B wetland, the lake has been stayed within the metropolitan area of Istanbul overtime. The samples from the surface water were taken monthly by using Nansen bottles at 5 sampling sites through the period of March-November. After experimental procedures, a total of 46 taxa were recorded belonging to Bacillariophyta (20), Charophyta (4), Chloro . . .phyta (6), Cryptophyta (1), Cyanobacteria (4), Euglenozoa (3), and Miozoa (8) divisions. The phytoplankton densities were found to be varied from 76 individual c More less

Osman TUTKUN

Article | 2016 | Desalination and Water Treatment57 ( 10 )

This study reports the selective separation of Co (II) from mixtures of cobalt and nickel solutions using cellulose tri-acetate (CTA)-based polymer inclusion membranes, which incorporated the commercial extractant trioctylmethylammonium chloride (Aliquat 336). Tributylphosphate (TBP) was used as a modifier, and 2- nitro phenyl pentyl ether (2-NPPE) was applied as the plasticiser to prepare the membranes. Several important transport parameters such as the plasticiser concentration, carrier type, carrier concentration, pH of acid, stirring speed, stripping solution type and concentration, complexing reagent (NH4SCN) concentration and . . .synergistic effect of the modifier were discussed. At the optimum conditions, following results were found: plasticiser concentration 0.2mL, feed solution pH 4, feed phase stirring speed 900rpm, stripping solution 1M NH3+1M TEA, complexing reagent (NH4SCN) concentration 0.5M and modifier TBP 25% w/w. Effective extraction was carried out under these conditions. The recovery factor of the cobalt ions was 100% for 4h. - Author Keywords: Polymer inclusion membranes; Aliquat 336; Plasticiser; Stripping solution More less

İbrahim İlker ÖZYİĞİT

Article | 2021 | Desalination and Water Treatment225

n this study, the level of water pollution in Lake Terkos, one of the important drinking water resources of Istanbul Metropolitan, was examined by determining the phytoplankton distribution, some physicochemical parameters, nutrients and heavy metal concentrations. For this purpose, samples were collected from eight sampling stations in March and September from the surface water. 34 taxa, from 8 divisions were categorized as Bacillariophyta (17), Charophyta (2), Chlorophyta (5), Cryptophyta (1), Cyanobacteria (5), Euglenozoa (2), Miozoa (1) and Ochrophyta (1). The habitat of blue-green algae Anabaena spiroides (Klebahn), which was f . . .ound to be dominant in Lake Terkos, was identified as eutrophic as well as stratified signifying shallow lakes with low nitrogen content. Recording high reproduction of Anabaena spiroides particularly in autumn demonstrated that the characteristics of the lake was altering from mesotrophic to eutrophic. The measured heavy metal concentrations denote that the Lake Terkos was extremely polluted by some metals/ metalloids. Particularly boron (B) and cadmium (Cd) concentrations show a class of 4 water quality. Since it fulfills the demand for drinking water in Istanbul to a large extent, it is crucial to take measures to improve the water quality of Lake Terkos urgently. Also it is considered that, limnological monitoring studies must be carried out continuously at the lake for controlling the water quality More less

Ali Osman SOLAK

Article | 2018 | Desalination and Water Treatment112

In this research, (Z)-2-(2-(hydroxyimino)-2-(3-methyl-3-phenylcyclobutyl) ethyl)-3a,7a-dihy-dro-1H-isoindole-1,3(2H)-dione, HMPD molecule has been grafted to the glassy carbon (GC) electrode surface. The HMPD-modified GC electrode has been originally developed and it used for the quantitative determination of Cu(II) in flour and water samples. The modification steps have been performed using cyclic voltammetry (CV). CV, electrochemical impedance spectroscopy and scanning electron microscopy have been employed for the characterization processes. Cu(II) standard solutions changing from 1.0 x 10(-9) to 1.0 x 10(-3) M have been prepared . . . and the corresponding peak currents have been measured. From the obtained data calibration equation has been calculated I-p = -1.555C(cu) + 15.86 which is having a 0.9974 correlation coefficient. 10.0 mL of flour and water samples have been mixed with 10.0 mL Britton-Robinson (BR) buffer solution (pH = 5.00) and HMPD/GC sensor electrode has been kept in these mixed solutions for 90 min. Differential pulse voltammetric (DPV) technique has been applied for the measurement of the peak currents. After the application of the developed sensor electrode for Cu(II) detection in flour and water samples, Cu(II) ion concentrations have been calculated from the obtained peak current values, 1.97 and 2.46 mu A. The Cu(II) ion concentrations have been calculated as 1.17 x 10(-9) and 2.41 x 10(-9) M, respectively More less