H. İbrahim Ekiz

APPLICATION OF FREUNDLICH AND LANGMUIR MODELS TO MULTISTAGE PURIFICATION PROCESS TO REMOVE HEAVY METAL IONS BY USING SCHIZOMERIS LEIBLEINII

The adsorption of iron(III), lead(II) and cadmium(II) ions onto Schizomeris leibleinii, a green alga, was studied with respect to initial pH, temperature, initial metal ion and biomass concentration to determine the optimum adsorption conditions. Optimum initial pH for iron(III), lead(II) and cadmium(II) ions were 2.5, 4.5 and 5.0 at optimum temperature 30°C, respectively. The initial adsorption rates increased with increasing initial iron(III), lead(II) and cadmium(II) ion concentrations up to 100, 100 and 150 mg l−1, respectively. The Freundlich and Langmuir adsorption isotherms were developed at various initial pH and temperature values. The adsorption of these metal ions to S. leibleinii was investigated in a two-stage mixed batch reactor. The residual metal ion concentrations (Ceq) at equilibrium at each stage for a given ‘quantity of dried algae (X0)/volume of solution containing heavy metal ion (V0)’ ratio were calculated using Freundlich and Langmuir isotherm constants. The experimental biosorption equilibrium data for iron(III), lead(II) and cadmium(II) ions were in good agreement with those calculated by both Freundlich and Langmuir models. The adsorbed iron(III), lead(II) and cadmium(II) ion concentrations increased with increasing X0/V0 ratios while the adsorbed metal quantities per unit mass of dried algae decreased.

A staged purification process to remove heavy metal ions from wastewater using Rhizopus arrhizus

Abstract The adsorption of iron(III), lead(II) and cadmium(II) ions onto dry cells of Rhizopus arrhizus was investigated in a four-stage batch reactor. The adsorption in multi-stage reactors can be considered as a multi-stage equilibrium depending on the adsorption equilibrium and mass balance. The Freundlich and Langmuir adsorption isotherms were developed to evaluate the biosorptive uptake capacity of the biomass. The Freundlich and Langmuir constants at optimum adsorption conditions were used to calculate the residual or adsorbed metal ion concentrations at equilibrium at each stage for a given volume of solution containing heavy metal ion/quantity of dried biomass ( V 0 X ) ratio. The experimental equilibrium values were compared with the values obtained from Freundlich and Langmuir isotherm equations. These results showed that the increase in biomass quantity or the decrease of V 0 X ratios affected the quantities of iron, lead and cadmium removed from aqueous solution.

Effect of Ultraviolet and Far Infrared Radiation on Microbial Decontamination and Quality of Cumin Seeds

UNLABELLED Cumin seeds might be exposed to a high level of natural bacterial contamination, and this could potentially create a public health risk besides leading to problems in exportation. Ultraviolet (UVC) and far infrared (FIR) radiation has low penetration power, and due to that, there might be no detrimental defects to the products during a possible decontamination process. Therefore, the objective of this study was to determine the effect of UVC and FIR treatment on microbial decontamination and quality of cumin seeds. For this purpose, FIR treatment at different exposure times and temperatures were applied followed by constant UVC treatment with an intensity of 10.5 mW/cm² for 2 h. Total mesophilic aerobic bacteria of the cumin seeds were decreased to the target level of 10⁴ CFU/g after 1.57, 2.8, and 4.8 min FIR treatment at 300, 250, and 200 °C, respectively, following a 2 h UVC treatment. Under the given conditions, a complete elimination for total yeast and molds were obtained while there were no significant changes in volatile oil content and color of the cumin seeds. Consequently, combined UVC and FIR treatment was determined to be a promising method for decontamination of the cumin seeds. PRACTICAL APPLICATION This research attempts to apply UVC and far infrared (FIR) radiation for pasteurization of cumin seeds. The data suggested that combined UVC and FIR radiation treatments can become a promising new method for pasteurization of cumin seeds without causing any detrimental defect to the quality parameters. The results of this industry partnered (Kadioglu Baharat, Mersin, Turkey--http://www.kadioglubaharat.com) study were already applied in industrial scale production lines.

Water vapor adsorption of ready-to-cook wheat

Abstract Water vapor adsorption of bulgur and hedik samples made from Triticum durum (Gediz 75) and Triticum aestivum (Panda) wheat were investigated. Experiments were conducted at 5, 15, 20, 30, and 40 °C for bulgur and at 20 °C for hedik samples between relative humidity (RH) of 11% and 100%. Bulgur samples became moldy before attaining equilibrium above 5 °C and 81% RH between 4 and 28 d depending on temperature (T). Hedik samples did not become apparently moldy and always had smaller equilibrium moisture content (X) than their bulgur counterparts at 20 °C and same RH. Type of wheat governed adsorption of the products. Bulgur and hedik of Gediz wheat always exhibited higher water adsorption capacity than bulgur and hedik of Panda wheat, respectively. The Guggenheim–Anderson–Boer model fitted all samples very well under the given conditions. The monolayer moisture content (Xm) was 9.7% and 9.6% (d.b.) for bulgur and hedik of Gediz wheat, and 7.5% and 6.5% (d.b.) for bulgur and hedik of Panda wheat, respectively. The heat of adsorption ( Q ) of bulgur samples was not affected by temperature and decreased with increasing X. Gediz bulgur had higher Q values than Panda bulgur up to the capillary condensation region. The average Q was obtained as 75, 50, and 45 kJ/mol for Gediz bulgur, and 73, 49, and 45 kJ/mol Panda bulgur for the monolayer, multilayer, and capillary adsorption regions, respectively.