Search

WOS: 000404310100002, PubMed ID: 28412579, Removal of toxic chemicals from environmental samples with low-cost methods and materials are very useful approach for especially large-scale applications. Green algae are highly abundant biomaterials which are employed as useful biosorbents in many studies. In the present study, an interesting type of green algae, Cladophora hutchinsiae (C. hutchinsiae) was used for removal of highly toxic chemical such as uranium. The pH, biosorbent concentration, contact time and temperature were optimized as 5.0, 12 g/L, 60 min and 20 degrees C, respectively. For the equilibrium calculations, three well known isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich) were employed. The maximum biosorption capacity of the biosorbent was calculated as about 152 mg/g under the optimum batch conditions. The mean energy of biosorption was calculated as 8.39 kJ/mol from the D-R biosorption isotherm. The thermodynamic and kinetic characteristics of biosorption were also investigated to explain the nature of the process. The kinetic data best fits the pseudo-second-order kinetic model with a regression coefficient of > 0.99 for all studied temperatures. The calculated Delta H degrees and Delta G degrees values showed that the biosorption process is exothermic and spontaneous for temperatures between 293 and 333 K. Furthermore, after seven cycling process, the sorption and desorption efficiencies of the biosorbent were found to be 70, and 58%, respectively meaning that the biosorbent had sufficiently high reusability performance as a cleanup tool. (C) 2017 Elsevier Ltd. All rights reserved., Cumhuriyet University; Gaziosmanpasa University; Karadeniz Technical University; Turkish Academy of Sciences, The authors are fully grateful for the financial support of the Unit of the Scientific Research Projects of Cumhuriyet University, Gaziosmanpasa University and Karadeniz Technical University. Dr. Mustafa Tuzen also thanks to Turkish Academy of Sciences for financial support.

WOS: 000356747300029, Compound 1 has been prepared by the reaction of 4-nitrophthalonitrile with triethanolamine. Compound 3 has been synthesized with quaternarization of compound 2 which prepared by cyclotetramerization of compound 1. The synthesized compounds have been characterized by elemental analysis, H-1 NMR, UV Vis, IR and MALDI-TOF MS spectral data. The interaction of compound 3 with calf thymus DNA was investigated spectrophotometrically. The phthalocyanine-DNA binding mechanism as well as the thermodynamic properties of binding was studied. The thermal denaturation profile, gel electrophoresis studies and the viscosity experiments were also conducted to clarify the mechanism. The replacement of ethidium bromide with phthalocyanine was monitored flourometrically to verify the binding mode. The Stern Volmer plot has nonlinear characteristic that implies both collisions of molecules and formation of ground state complexes which causes the fluorescence quenching. The experimental results indicate that the synthesized ball type water soluble phthalocyanine binds to calf thymus DNA via mainly intercalation. (C) 2015 Elsevier Ltd. All rights reserved.