Necmettin Caner

Isotherm and kinetic studies of Burazol Blue ED dye biosorption by dried anaerobic sludge

Biosorption potential of dried anaerobic sludge (DAS) for Burazol Blue ED (BB) was studied with respect to pH, equilibrium time, initial dye concentrations and temperature to determine equilibrium and kinetic models. The most suitable pH, equilibrium time and initial dye concentration were determined as 0.5+/-0.03, 75 min and 150 mg/L, respectively, at a biomass dosage of 0.4 g/L and 25 degrees C+/-1.0. The equilibrium data was best described by the Langmuir isotherm model. Maximum uptake capacity (q(m)) of DAS for the dyestuff (BB) were 118.3, 125.8 and 127.5mg/g biomass at temperatures of 25, 40 and 50 degrees C, respectively, indicating that the biosorption process is spontaneous and favored at higher temperatures. The overall biosorption process was best described by pseudo-second-order kinetic model. Gibbs free energy changes were calculated as -356.8, -519.7 and -520.6J/mol at 25, 40 and 50 degrees C, respectively.

Energy and Exergy Evaluation of an Air Separation Facility: A Case Study

In this study, an air separation plant working according to the principle of separation of two columns and producing argon, nitrogen, and oxygen with a daily capacity of 250 tons was analyzed in detail with respect to the first and second laws of thermodynamics and the results were evaluated. The energy and exergy values for each point defined in the system were obtained. By using these values, thermodynamic evaluations for both the whole system and also its components were made. The efficiency values of energy and exergy, the values of energy losses and exergy destruction rates, the EIP (energetic improvement potential rate), ExIP (exergetic improvement potential rate), and the production of entropy values were found as 0.453, 0.79, 4368.475 kW, 10535.875 kW, 2391.535 kW, 3800.485 kW, and 35.347 kW/K, respectively. The energy and exergy efficiencies of the plant were found to be 45.3% and 13.1% respectively.

Spectroscopic and acoustic study in binary mixtures of glycerol with several alkanols

Speeds of sound and densities of glycerol + methanol, glycerol + ethanol and glycerol + 2-propanol, were measured over the entire composition range at 298.15 K. The excess volumes, the isentropic compressibilities, molar isentropic compressibilities and excess molar isentropic compressibilities and excess speeds of sound were estimated from the densities and speeds of sound. The results indicated the presence of interactions between unlike molecules through intermolecular hydrogen bonding. The excess volumes, excess molar isentropic compressibilities and excess speeds of sound of the binary mixtures were fitted to the Redlich–Kister equation. The infrared spectra of glycerol + methanol, glycerol + ethanol and glycerol + 2-propanol have been recorded for various concentrations at room temperature. IR stretching frequencies, bandwidths and relative intensities have been estimated and analysed. Acoustic and spectroscopic measurements showed a good correlation to explain the existence of interactions between unlike molecules through intermolecular hydrogen bonding.

Copper(II)-pyrazine-2,3-dicarboxylate Coordination Polymer with Monoethanolamine, [Cu(μ3-pzdc)(mea)]n

A novel Cu(II)-pyrazine-2,3-dicarboxylate complex with monoethanolamine ligand (mea), [Cu(μ3-pzdc)(mea)]n(1), has been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structure of polynuclear complex has been determined by the single crystal X-ray diffraction technique. The pyrazine-2,3-dicarboxylate dianion exhibits tetradentate-μ3 bridging ligand through three carboxylate oxygens and one nitrogen atom. The complex contains two copper(II) ions that exhibit two different coordination environments with two mea, two pzdc ligands, respectively. The Cu1(II) ion is coordinated by two carboxylate oxygen atoms, two N atoms and two O atoms of symmetry related carboxylate group, forming a distorted octahedral geometry, while Cu2(II) ion is coordinated by two bidentate mea ligands and remaining two coordination sites of distorted octahedral geometry are occupied by two carboxylate oxygen atoms of neighboring Cu1 molecule. Thermal analysis property and thermal decomposition mechanism of complex have been investigated by using thermal analyses techniques (TG, DTG and DTA).Graphical AbstractWe have synthesized and structurally characterized a novel 2D Cu(II)-pyrazine-2,3-dicarboxylate coordination polymer with monoethanolamine ligand (mea), [Cu(μ3-pzdc)(mea)]n. The pyrazine-2,3-dicarboxylate ligand exhibits tetradentate-μ3 bridging ligand through three carboxylate oxygens and one nitrogen atom. The complex contains two copper(II) ions that exhibit two different coordination environments with two mea, two pzdc ligands, respectively. The crystal packing of complex is a composite of intra- and intermolecular hydrogen bonding and C–O···π interactions.The molecular structure of [Cu(μ3-pzdc)(mea)]n

Biosorption of Reactive Yellow 145 Dye by Dried Penicillum restrictum: Isotherm, Kinetic, and Thermodynamic Studies

Removal of dyes from wastewaters causes a big concern from the environmental point of view due to their extreme toxicity towards aquatic life and humans. Commonly used traditional methods to treat these effluents are ineffective because dyes show resistance to many chemicals, oxidizing agents, and light. In this context, the biosorption process has attracted great attention in recent years since they utilize not only cheap plant materials but also a wide variety of microorganisms as biosorbing agents, displaying a high dye-binding capacity. In this study, biosorption potential of dried Penicillum restrictum (DPR) for Reactive Yellow 145 (RY 145) was studied with respect to pH, equilibrium time, and temperature to determine equilibrium and kinetic models. The most suitable pH and equilibrium time were determined as 1.0 ± 0.05 and 75 min respectively, at a biomass dosage of 0.4 mg L−1 and 20 ± 0.5°C. Data obtained from batch studies fitted well with the Dubinin-Radushkevich (D-R) followed by the Freundlich and Langmuir isotherm models. Maximum uptake capacities (qm) of DPR for the dyestuff (RY 145) were 109.7, 115.2, and 116.5 mg g−1 biomass at temperatures of 20, 30, and 40 ± 0.5°C, respectively. The overall biosorption process was best described by the pseudo-second-order kinetic model. Gibbs free energy changes were calculated as −384.6, −273.5, and −245.9 J mol L−1 at 20, 30, and 40 ± 0.5°C, respectively.

Optimum insulation thickness for piping system using exergy and environmental methods

Optimum insulation thickness for a piping system is investigated using a novel method that combines exergy and environmental analysis. Rockwool and glasswool are chosen as insulation materials for the system and the analysis was carried out for the city of Bilecik, located in the Marmara Region of Turkey. Investigation is performed for the different nominal pipe sizes (NPS or diameter nominal: DN) of 50, 100 and 150. The environmental impacts of the various parameters are described. Results for the environmental impact of the system, the net environmental saving, exergetic heat loss, the net exergy saving, fuel consumption and CO2 emissions according to insulation thickness are presented. Optimum points are calculated as 0.109 m, 0.126 m and 0.137 m for DN 50, 100, and 150, respectively for the glasswool. Optimum insulation thickness for the rockwool was determined as 0.064 m, 0.073 m and 0.079 for DN 50, 100, and 150, respectively.