Ensar Oguz

REMOVAL OF PHOSPHATE FROM WASTEWATERS

Abstract Gas concrete waste was used to remove phosphate from aqueous solutions in this study. The influence of suspension pH, temperature, mixing rate, and gas concrete dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, both values of BET–N 2 specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. In this study, phosphate removal in excess of 99% was obtained and it was concluded that wastes of gas concrete are an efficient adsorbent for the removal of phosphate. The removal of phosphate predominantly takes place by precipitation mechanism and the weak physical interactions between the surface of adsorbent and the metallic salts of phosphate.

Biosorption of cobalt(II) with sunflower biomass from aqueous solutions in a fixed bed column and neural networks modelling.

The effects of inlet cobalt(II) concentration (20-60 ppm), feed flow rate (8-19 ml/min) and bed height (5-15 cm), initial solution pH (3-5) and particle size (0.25<x<0.5, 0.5<x<1 and 1<x<2 mm) on the breakthrough curves were investigated. The highest bed capacity of 11.68 mg/g was obtained using 40 ppm inlet cobalt(II) concentration, 5 cm bed height and 8 ml/min flow rate, pH 6.5 and 0.25<x<0.5 mm particle size. According to the BET (N2) measurements, the specific surface area of the shells of sunflower biomass was found to be 1.82 m(2)/g. A relationship between the predicted results of the ANN model and experimental data was conducted. The ANN model yielded determination coefficient of (R(2) 0.972), standard deviation ratio (0.166), mean absolute error (0.0158) and root mean square error (0.0141). The results indicated that the shells of the sunflower biomass is a suitable biosorbent for the uptake of cobalt(II) in fixed bed columns.

Removal of Phosphate from Waste Waters by Adsorption

In this study, the adsorption of phosphate on gas concrete from aqueous solutions has been studied as functions of temperature, mixing rates and suspension pH. Over 99% of phosphate removal was found. The chemical composition of the gas concrete has been defined by X-ray analysis. Experimental data was fitted to the Langmuir equation in order to Langmuir coefficients. After calculating Langmuir coefficients, adsorption free energy (Δ G0ads.) has been determined. In order to gather information about adsorption mechanism, electrophoretic mobilites of particles were measured at various pHs by using Zeta meter 3.0+. It has been found that the adsorption is driven by the interactions between the ionizations of CaO and Al2O3 and the formation of AlPO4. According to the BET (N2) measurements, the specific surface area of gas concrete was found as 22 m2g-1. The surface area after adsorption has been found as 17 m2g-1. The surface area covered by adsorbate has been found as 5.23 m2g-1 by usingas = nsm. am. NA. These two areas determined by BET and Langmuir model were close to each other (BET: 22 m2g-1–17 m2g-1).

Determination of the apparent rate constants of the degradation of humic substances by ozonation and modeling of the removal of humic substances from the aqueous solutions with neural network.

In this study, the degradation rate constants of humic substances by ozonation under the different empirical conditions such as ozone-air flow rate, ozone generation potential, pH, temperature, powdered activated carbon (PAC) dosage and HCO(3)(-) ions concentration were determined. The ozonation of humic substances in the semi-batch reactor was found to fit pseudo-first-order reaction. The values of apparent rate constant of humic substances degradation increased with the increase of initial ozone-air flow rates, ozone generation potential, pH, temperatures and PAC dosage, but decreased with the increase of HCO(3)(-) concentration of the solution. Using Arrhenius equation, the activation energy (E(a)) of the reaction was found as 1.96 kJ mol(-1). The reaction of ozonation of humic substances under the different temperatures was defined as diffusion control according to E(a). The model based on artificial neural network (ANN) could predict the concentrations of humic substances removal from aqueous solution during ozonation. A relationship between the predicted results of the designed ANN model and experimental data was also conducted. The ANN model yielded determination coefficient of (R(2)=0.995), standard deviation ratio (0.065), mean absolute error (4.057) and root mean square error (5.4967).

Interaction between air pollution and meteorological parameters in Erzurum, Turkey

In recent years, the rapid increase in population density has caused increases in the consumption of fuel, and the outdoor air quality has deteriorated in the crowded urban areas of Turkey. Erzurum, a city in the eastern part of Turkey, is influenced by air pollutants such as SO2 and suspended particles. It is known that, in general, the air pollution concentrations have a close relationship with meteorological factors. In this study, the relationship between outdoor air quality data and meteorological factors, such as wind speed, rainfall, temperature, sunshine hours and relative humidity, is statistically analysed, using the code SPSS. According to the results obtained through multiple linear regression analysis, there are moderate levels of correlation between SO2 and particle concentrations and meteorological factors in Erzurum.

Prediction of adsorption rate of phosphate removal from wastewater with gas concrete

Gas concrete, a conventional structural material, is used to remove phosphate from wastewater. A batch study of phosphate removal from wastewater with waste particles of gas concrete has been performed. The concentration-time graphs were plotted against pH, temperature, and agitation speed, and the reaction rate equation was adapted to adsorption. The differential method was used to define reaction rate. The adsorption rates, reaction rate constants, and reaction rates were determined by tangent lines of drawn curves at different concentrations, depending on pH, temperature, and agitation speed. The adsorption rate increased with pH and temperature. The maximum effect of agitation speed on the adsorption rate was observed at 150 rpm. The activation energy of reaction and the pre-exponential factor were calculated using the Arrhenius equilibrium equation. The zeta potentials of waste gas concrete were determined at various pH values. The surface area of gas concrete was obtained using BET apparatus as 22 m²/g. The composition of gas concrete was determined by X-ray diffractometry. The results indicate that gas concrete is an effective adsorbent to remove phosphate from wastewater.

Investigation on the Removal of COD from Colored Aqueous Solutions with O3, H2O2, HCO3−, and PAC

In this study, chemical oxygen demand (COD) was removed using different processes containing O3, H2O2, HCO3−, and powder activated carbon (PAC) from the synthetic dye solutions. The effects of the experimental parameters such as temperature, ozone dose, dye concentration, pH, and time on the removal of COD were investigated. The Taguchi method was applied to determine the optimum conditions. An orthogonal array L18 (21 * 37) experimental design plan was selected to define the optimum conditions. In addition, the mechanism of the COD removal was explained on the basis of the results of Fourier transform infrared (FTIR) spectroscopy. To gain information about COD removal mechanism at various pHs, electrophoretic mobilities of particles were measured. The chosen experimental parameters and their ranges are: (0–39 mM); temperature (18–70 °C); ozone dose (164–492 mg/min); dye concentration (200–600 ppm); PAC (0–1.5 g); H2O2 (0–0.056 mM); pH (3–12); and time (10–30 min). Under these optimum conditions, it was found that the COD removal efficiency from the synthetic dye solutions was 98%.

COD Removal from leachate by electrocoagulation process: treatment with monopolar electrodes in parallel connection

This study examines the removal of chemical oxygen demand (COD) from landfill leachate generated from the municipal landfill site of Bingol, Turkey. The effect of parameters such as current density, pH, and inter-electrode distance during the electrocoagulation (EC) process on COD removal of the process was investigated. Moreover, for COD removal, the energy consumption and operating costs were calculated for iron electrode under the EC conditions. COD removal efficiency was 72.13% at the current density of 16 mA m-2, pH of 8.05, and the inter-electrode distance of 9 mm at the detention time of 60 min with iron electrode and the COD concentration was reduced from 6,100 mg L-1 to 1,700 mg L-1 by EC. The highest value of the electrical energy and electrode consumptions per kg of COD in the optimum conditions were determined as 0.055 kWh kg-1 COD and 3.43 kg kg-1 COD and the highest operating cost value was found to be 1.41 US

Batch Biosorption of Copper(II) by Sunflower Shell

kg-1 COD for 0-60 min time intervals.

Removal of phosphate from aqueous solution with blast furnace slag

In this manuscript, Cu (II) uptake by Sunflower Shell from aqueous solutions was investigated using batch biosorption techniques. The biosorption equilibrium studies were realized as a function of contact time, initial Cu (II) concentration, biosorbent dosage, pH, temperature, agitation rate and particle size. In addition, the mechanism of the Cu (II) removal was explained on the basis of the results of Fourier Transform Infrared (FTIR) spectroscopy. In order to gather information about the adsorption mechanism at various pHs, electrophoretic mobilites of particles were measured. The efficiency of Cu (II) ions uptake from aqueous solutions increased as pH, temperature and agitation rate of the solution increased, but decreased with the increase of biosorbent particle size.