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    Application of Magnetic Nanoparticles to Residue Analysis of Organochlorine Pesticides in Water Samples by GC/MS
    (Aoac Int, 2012) Ozcan, Senar; Tor, Ali; Aydin, Mehmet Emin
    This paper describes a novel magnetic-SPE method for the determination of organochlorine pesticides (OCPs) in environmental water samples by use of Fe3O4-magnetic nanoparticles (MNPs) coated with oleic acid followed by GC/MS. The chemisorption of oleic acid onto Fe3O4-MNPs provides reusability of the developed sorbent materials several times. The effects of different parameters such as pH, desorption solvent, contact time, temperature, ionic strength, and sorbent dosage on the efficiency of magnetic-SPE were investigated. The optimized SPE method involved shaking 50 mL of water sample (pH 4) with 50 mg oleic acid coated Fe3O4-MNPs for 1 h, isolating the sorbent with an Nd-Fe-B magnet, and eluting the OCPs with methanol. An ionic strength of 0.1 M and temperature of 15 C provided the maximum extraction efficiency. The LOQs were in the range of 0.006 to 0.048 mu g/L. For three fortification levels, recoveries were in the range of 44-108%, with RSD <5%. The developed SPE method was successfully applied to real water samples, and it is viable, rapid, and easy to use for analysis of OCPs in water samples.
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    Coagulation, flocculation and chemical precipitation
    (Iwa Publishing, 2012) Aydin, Mehmet Emin; Lazarova, Zdravka; Tor, Ali; Ozcan, Senar
    [Abstract Not Availabe]
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    Investigation on the Levels of Heavy Metals, Polycyclic Aromatic Hydrocarbons, and Polychlorinated Biphenyls in Sewage Sludge Samples and Ecotoxicological Testing
    (Wiley, 2013) Ozcan, Senar; Tor, Ali; Aydin, Mehmet Emin
    This article reports the levels of heavy metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in sewage sludges taken from two wastewater treatment plants (WWTPs) in Konya (Turkey) as well as their toxicity. The concentrations of heavy metals, including Cd, Cr, Cu, Ni, Pb, Zn in sludge samples from plant #2 did not exceed the limits described in both Turkish and European Union (EU) regulations. The similar result was observed in samples obtained from plant #1, except for sludge taken in May 2010. The sigma PAHs concentration ranging from 960 to 7680 mu g/kg dry matter shows that sewage sludges from plant #1 could be used for agricultural purpose. However, sewage sludges from plant #2 (sigma PAHs: 107717509 mu g/kg dry matter) was not suitable for using in agriculture. The concentrations of sigma PCBs in all investigated sludges from plant #1 (7.46709.36 mu g/kg dry matter) and plant #2 (14.12788.47 mu g/kg dry matter) were lower than the limits reported in Turkish and EU regulations. The probable sources of PAHs and PCBs in sludges were also determined. The ecotoxicological tests examined on Vibrio fischeri and Lepidium sativum organisms showed that sludges from plant #1 had no significant toxic effect, while sludges from plant #2 had acute toxic property. Finally, all the results showed that sewage sludges from plant #1 had potential for being used in agriculture.
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    Levels of Organochlorine Pesticides and Heavy Metals in Surface Waters of Konya Closed Basin, Turkey
    (Hindawi Ltd, 2013) Aydin, Mehmet Emin; Ozcan, Senar; Beduk, Fatma; Tor, Ali
    The concentrations of organochlorine pesticides (OCPs), including alpha-, beta-, gamma-, and delta-hexachlorocyclohexane (HCH), heptachlor, heptachlor epoxide, dieldrin, aldrin, endrin, endrin aldehyde, endrin ketone, endosulfan I, endosulfan II, endosulfan sulfate, p,p'-DDE, p,p'-DDD, p,p'-DDT, methoxychlor, chlordane I, chlordane II, and heavy metals, such as As, Cr, Cu, Fe, Mn, and Ni in surface water samples from the Konya closed basin were determined to evaluate the level of contamination. Among all HCH isomers, beta-HCH is the main isomer with a concentration range of 0.015-0.065 mu g/L. DDE, DDD, and DDT were almost determined in all samples, in which DDE isomer had the highest concentration ranged from not detected to 0.037 mu g/L. In all studied OCPs, aldrin showed the highest concentration at 0.220 mu g/L. The concentrations of heavy metals in water samples were observed with order: Mn < Cu < Ni < As < Cr < Fe. In some samples, As, Fe, and Cr concentrations exceeded the drinking water quality recommended by EU, US EPA, WHO, and Turkish Regulation, while Cu, Ni, and Mn concentrations are below the guideline values. The levels of both OCPs and heavy metals were also compared with other previously published data.
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    Sedimentation and flotation
    (Iwa Publishing, 2012) Tor, Ali; Ozcan, Senar; Aydin, Mehmet Emin
    [Abstract Not Availabe]
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    Sorption of phenol from aqueous solution by novel magnetic polysulfone microcapsules containing Cyanex 923
    (Elsevier, 2012) Ozcan, Senar; Tor, Ali; Aydin, Mehmet Emin; Beduk, Fatma; Akin, Ilker
    This paper describes the sorption of phenol from aqueous solution by using novel magnetic polysulfone (PSF) microcapsules containing Fe3O4 nanoparticles and mixture of trialkyl-phosphine oxides (Cyanex 923) (Cyanex 923/Fe3O4@PSF microcapsules). The preparation of the Cyanex 923/Fe3O4@PSF microcapsules was based on the phase-inversion technique. The prepared microcapsules were characterized by using Fourier Transform Infrared Spectroscopy (FT-IR), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Vibrating Sample Magnetometer (VSM). Fe3O4 nanoparticles in the microcapsules provided easier separation via application of external magnetic field. The experiments indicated that phenol could be removed from aqueous solution at a pH range between 3 and 9. The Cyanex 923/Fe3O4@PSF microcapsules prepared with dispersed phase containing 3.35% of Cyanex 923 (by wt.) provided the highest removal. The sorption reached an equilibrium in 120 min and it obeyed the pseudo-second order kinetic model. The non-linear Chi-square (chi(2)) statistical test showed that Langmuir isotherm model better represented the sorption data in comparison to Freundlich and Redlich-Peterson models. The Langmuir sorption capacity (Q(o)) and sorption constant (b) were 0.664 mmol/g and 0.855 L/mmol, respectively. The regenerated microcapsules could be used five times with no change in their sorption capacity and magnetic separability. (C) 2012 Elsevier Ltd. All rights reserved.