Browsing by Author "Erkus, Ayse"

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Application of Response Surface Methodology (Rsm) To Optimize the Adsorption Conditions of Cationic Basic Yellow 2 Onto Pumice Samples as a New Adsorbent
(Parlar Scientific Publications (p S P), 2017) Ozturk, Dilara; Sahan, Tekin; Bayram, Tuba; Erkus, Ayse
In this study, optimization of medium conditions for CBY2 adsorption by pumice was studied through experimental design. For CBY2 adsorption, initial CBY2 concentration (C-o, mg/L), pH and contact time (min.) were determined as medium conditions. Central Composite Design (CCD) within response surface methodology (RSM) was applied to develop a response surface for optimization of adsorption conditions. The optimum conditions were determined as C-o = 154.28 mg/L, pH = 6.13 and contact time = 47.98 min. Results of experiments determined that at these optimum conditions, optimum adsorbed amount was 12.62 mg/g and adsorption yield was 81.79%. A quadratic model was developed by CCD to represent CBY2 adsorption.
The Examination of Paracetamol and Diclofenac Removal in Activated Sludge Systems Under Different Operating Conditions
(Health & Environment Assoc, 2015) Erkus, Ayse; Basibuyuk, Mesut; Erkus, Fatih Sevki
Pharmaceuticals compounds are widely used to maintain human and animal health worldwide. After human consumption pharmaceutical compounds in the urban aquatic environment reach to the wastewater facilities and eventually find their way to the surface waters. Aim of this study was to determine the effects of various sludge retention times (SRT) and hydraulic retention times (HRT) using lab-scale continuous stirred tank reactor (CSTR) for the removal of diclofenac and paracetamol in activated sludge. In order to find out removal rates of these pharmaceutical compounds, activated sludge reactor were operated at different sludge retention times (SRT: 10, 20, 30 days) and different hydraulic retention times (HRT: 12 and 24 hours). The highest removal rates were obtained under 30 days of SRT and 24 hours of HRT operating conditions. Maximum removal of 95% was observed for paracetamol and 44% for diclofenac. The operational implementation of SRT and HRT has been shown to increase the removal efficiency of pharmaceutical compounds.
Extended Aeration Activated Sludge Reactor (Eaasr) for Removal of Nitrobenzene: Air Stripped or Biologically Removed
(Walter de Gruyter Gmbh, 2016) Keskinkan, Olcayto; Cakir, Alev; Erkus, Ayse; Yilmaz, Turan; Ersu, Cagatayhan Bekir
In this study, the performance of an extended aeration activated sludge reactor (EAASR) was investigated for the removal of nitrobenzene (NB), a commonly used organic chemical in various industries. In a set of experiments, increasing NB concentrations between 1 and 800 mg/L were applied to the EAASR. Synthetic wastewater containing NB was successfully treated up to 92.0 and 100.0% in terms of chemical oxygen demand (COD) and NB removal. The major NB removal mechanism in this EAASR was assessed to be air stripping after kinetic evaluation as compared to somewhat limited bacterial degradation of NB. Although NB is known to be toxic, the removal efficiency of NB was never below 97.4% even at high NB concentrations. Under lower NB concentrations, it was found that the bacterial floc formation was intact with existing Ciliata and Rotifera. However, at higher NB concentrations, free swimming Ciliata and Rotifera specimens disappeared while the flocs became smaller and dispersed.