Behzat Balci

Adsorption of Bisphenol-A by Eucalyptus bark/magnetite composite: Modeling the effect of some independent parameters by multiple linear regression:

In the present study, Eucalyptus camaldulensis bark/magnetite composite was used for potential application as a low-cost adsorbent for the removal Bisphenol-A. The effects of various independent parameters, contact time, initial Bisphenol-A concentration, temperature, pH, and Eucalyptus camaldulensis bark/magnetite composite dosage on adsorption were investigated. It was found that the adsorption capacity of Eucalyptus camaldulensis bark/magnetite composite increases with the increasing of Bisphenol-A concentration, temperature, and decreasing dosage of Eucalyptus camaldulensis bark/magnetite composite. The adsorption capacity was found to be 290.6 mg/g with 0.1 g Eucalyptus camaldulensis bark/magnetite composite at pH 7 and 50℃. The Freundlich isotherm model described the adsorption process better (R2 = 0.998) than the Langmuir, Dubinin–Radushkevich, Jovanovic, and Vieth–Sladek isotherm models. According to multiple linear regression analysis, Eucalyptus camaldulensis bark/magnetite composite dosage is the most effective parameter on adsorption capacity at equilibrium and independent variables accounted for 79.4% of the total variability of equilibrium adsorption capacity of Eucalyptus camaldulensis bark/magnetite composite.

Biotic and abiotic bisphenol-A removal from wastewater by activated sludge: effects of temperature, biomass, and bisphenol-A concentrations

In this study, bisphenol-A (BPA) removal from synthetic wastewaters using a laboratory-scale activated sludge system was achieved. Activated (biotic) sludge was used for BPA elimination, whereas inactivated (abiotic) sludge was used during the adsorption study. In each step, six different BPA concentrations (5, 10, 20, 30, 40, and 50 mg L(-1)) were tested, and temperatures were set to 10, 20, and 30 °C in the shakers. Four different activated sludge concentrations (1,000, 2,000, 3,000, and 4,000 mg TSS L(-1)) were applied in the biotic study, and only 2,000 mg TSS L(-1) was used in the abiotic study. After settlement of the sludge in the shakers, supernatants and control groups were filtered and analyzed for BPA using high performance liquid chromatography. In the biotic study, BPA and chemical oxygen demand (COD) concentrations were reduced at 100% and 99% levels, respectively. However, the BPA concentrations during the abiotic study changed slightly at varying temperatures, whereas there was no change of BPA concentration observed in the control groups. Results indicate that the main factor of BPA removal in an activated sludge system is biological. Kinetic studies were also conducted. BPA removal was best fit to zero- and first-order reaction kinetics, and the reaction rate constants are provided in this paper.

Removal of Bisphenol-A from Aqueous Solutions by Pseudomonas aeruginosa in Batch Reactors: Effect of Carbon Source, Temperature and Concentrations

Abstract This study was carried out to investigate the potential of Pseudomonas aeruginosa for the removal of bisphenol-A (BPA) from synthetic wastewater. To achieve this, BPA removal capability of P. aeruginosa with respect to BPA concentration, and temperature were examined in batch reactors. Experiments were conducted in the presence/absence of glucose, as a carbon source. The first set of experiments consisted of evaluating the kinetic of removal of BPA at different concentrations (5, 10, 20, and 30 mg BPA/L) without glucose. In the second set of experiments, three different glucose concentrations (0.5, 1.0, and 2.0 glucose/L) with BPA concentrations were tested. After settlement of the P. aeruginosa biomass in the shakers, supernatants and control groups were filtered and analyzed for BPA using high performance liquid chromatography. In the biotic study, BPA removal rates were between 63 % and 100 %. All concentrations of BPA under 20 mg/L were completely degraded at 25 and 35 ºC at first step. However, 30 mgBPA/L was decreased to 8.56 mg/L by P. aeruginosa at first step at 25 ºC. At the second step, all concentrations of BPA were completely degraded by the cells at the presence of glucose. Hence, it can be summarized that bisphenol A can be used by P. aeruginosa as an external carbon source in the wastewater environments.

Adsorption of Hexavalent Chromium by Eucalyptus camaldulensis bark/maghemite Nano Composite

Abstract In the present study, Eucalyptus camaldulensis bark/maghemite composite (ECMC) was used for potential application as a low-cost adsorbent for the removal of Cr(VI) from aqueous solution. The structural characterization, morphology and elemental analysis of ECMC were performed by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray (EDX) and X-ray Diffraction (XRD). The effects of various independent parameters, contact time, initial Cr(VI) concentration, temperature, pH, and adsorption were investigated. It was found that the adsorption capacity of ECMC increases with increasing Cr(VI) concentration and temperature. The optimum pH was found to be 2 for the removal of Cr(VI) by ECMC. The adsorption capacity was found to be 70.1 mg/g with 0.1 g ECMC at pH 2 and 30 °C. Additionally, 10 and 50 mg/L Cr(VI) were removed from 100 mL aqueous solution by 0.1 g ECMC with 99 % and 93.46 % removal efficiencies, respectively. Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Jovanovic, Smith, Koble Korringen, Vieth-Sladek and Sips Isotherm Models were applied to the experimental data to understand the adsorption mechanism better. The Freundlich Isotherm Model described the adsorption process better (R2 = 0.991) among the other isotherms studied.