Seval Kutlu Akal Solmaz

Advanced oxidation and mineralization of 3-indole butyric acid (IBA) by Fenton and Fenton-like processes.

The degradation and mineralization of 3-indole butyric acid (IBA) in aqueous solution was examined using Fenton and Fenton-like processes. Various operating conditions were evaluated including pH and the concentrations of iron ions (Fe(2+) and Fe(3+)) and hydrogen peroxide (H(2)O(2)). The highest COD removal efficiency was achieved at 0.2 mM/0.6 mM Fe(2+)/H(2)O(2) ratio and 0.2 mM/1.0 mM Fe(3+)/H(2)O(2) ratio at pH 3 for Fenton and Fenton-like processes, respectively. IBA degradation and mineralization exhibited pseudo-first-order kinetics while the depletion of H(2)O(2) and Fe(2+) or Fe(3+) exhibited zero-order kinetics during both processes in all experiments. 97% of IBA degradation proceeded via two distinctive kinetic regimes. The initial phase of the reaction was directly attributable to the Fenton reaction wherein nearly all of the OH radicals were generated. This was followed by a slower degradation phase, which can be thought of as a series of Fenton-like reactions within a Fenton process. In the Fenton-like process, the initial phase lasted longer than in the Fenton process because the generation of OH radicals proceeded at slower rate; however, 98% degradation of IBA was achieved. The mineralization of IBA was 16.2% and 50% for Fenton and Fenton-like processes, respectively. After 24 h, H(2)O(2) was the limiting reagent for further mineralization of IBA intermediates present in the system. The results of the study showed that Fenton Process may be more useful when only removal of IBA is required and mineralization is unnecessary. But if mineralization of IBA is needed, Fenton-like process gains more important than Fenton Process due to its mineralization efficiency.

An approach to wastewater treatment in organised industrial districts: a pilot-scale example from Turkey

In this study, a detailed wastewater profile and treatability studies of Demirtas Organized Industrial District (OID) were undertaken on a pilot-scale. The industrial categorisation of Demirtas OID was determined, and the wastewater characterisations of each industrial sector were analysed and the flow-rates were measured. The results were used to design a wastewater treatment plant for Demirtas OID. Pilot-scale chemical and biological treatability studies were carried out. The steady-state performance of the pilot-scale treatment system in removing chemical oxygen demand (COD) and suspended solids (SS) was studied for a period of three months. The removal efficiencies obtained in this study were 42% of COD and 67% of SS in the chemical treatment, and 84% of COD and 25% of SS in the biological treatment. The overall removal efficiency of the pilot-scale system was 91% COD and 75% SS. The pilot-scale study showed that the wastewater from Demirtas OID could be treated with biological and chemical methods, and the treated wastewater met the Regulation of Discharge Standards of Turkey. The significance of this study is that it is the first such system in Turkey to be tested on a pilot scale.

Removal of Pb(II) Ions in Fixed-Bed Column from Electroplating Wastewater of Bursa, an Industrial City in Turkey

Removal of Pb(II) ions from electroplating wastewater of Bursa, an industrial city in Turkey, was investigated in fixed-bed column. The experiments were conducted to study the effect of important design parameters such as column bed height and flow rate. The breakthrough profiles were obtained in these studies. At a bed height of 14 cm and flow rate of 6 mL/min, the metal-uptake capacity of poly(ethylene glycol dimethacrylate-1-vinylimidazole) [poly(EGDMA-VIM)] beads for Pb(II) ions was found to be 90 mg/g. Bed Depth Service Time (BDST) model was used to analyse the experimental data and evaluate the performance of adsorption column. For various flow rates, adsorption capacity per unit bed volume () and adsorption rate constant () are in the range of 2370–3560 mg/mL and 0.0225–0.0616 L/mg h, respectively. The saturated column was easily regenerated by 0.1 M HNO3 and the poly(EGDMA-VIM) beads in fixed-bed column could be reused for Pb(II) ions removal.

Treatment of 3-indole butyric acid with solar photo-catalytic reactor

Abstract Solar photo-catalytic process is an emerging and promising technology both as an alternative treatment to conventional wastewater treatment methods and enhancement of biodegradability of highly toxic and recalcitrant pollutants. In this study, results for the treatment of 3-indole butyric acid solutions using pilot scale solar photo-catalytic treatment process are presented. The effecting parameters, such as adsorption of 3-indole butyric acid on TiO2, pH, the initial concentration of 3-indole butyric acid and catalyst concentration, on the treatment of 3-indole butyric acid using solar photo-catalytic system were investigated. Solar photo-catalytic processes demonstrated high COD (>80%), TOC (>80%) and 3-indole butyric acid (>90%) removal efficiencies for the samples in this study. The increase of the 3-indole butyric acid concentration from 10 to 150 mg/L decreases the removal rate constant from 0.0757 to 0.0088 1/min in 240 min of oxidation using 100–1500 mg/L TiO2 at 3–9 pH.

Modelling Dimethoate Removal by Fenton-Like Process Using Response Surface Methodology

The (RSM) is a useful method for optimizing analytical methods and it has been applied to evaluate independent variables in FPs. In this study, the removal of dimethoate (DMT) which is a commonly used pesticide and has a toxic effect on the environment, was evaluated in terms of oxidation and mineralization efficiency using response surface methodology (RSM) in the Fenton-like process (FLP). The obtained optimum conditions for DMT oxidation and mineralization using the FLP included DMT/Fe+3/H2O2 ratio of 0.018 mM/0.03 mM/0.15 mM and reaction time of 65 min. DMT oxidation efficiency was 78% and mineralization efficiency was 18%. The initial DMT concentration was the most significant variable affecting both the oxidation and mineralization efficiency of DMT.

Multicomponent activated sludge model for reactors in series with recycling

Multicomponent models containing both substrate and biomass have an advantage over conventional models in seeking better understanding of activated sludge systems. Such models are also useful in the characterization of wastewater. Studies in recent years have shown that most of the soluble organic matter in the effluent of treatment systems consists of soluble microbial products that arise during biological treatment. In order to support experimental studies, mathematical models have also been developed to explain microbial product formation. In connection with the approaches in the literature, a mathematical model for estimating chemical oxygen demand in effluent in dispersed media has been developed in this study. The death-regeneration approach - an approach of multicomponent activated sludge models containing the formation of soluble inert organic matter with together carbon oxidation - was used. Because the differential equations developed for dispersed media have no analytical solutions, the system was represented with the in-series reactor approach, with the death-regeneration and hydrolysis concepts advised in the IAWPRC Task Group Model.