Papers by Kaan Yetilmezsoy
Sustainability
The suitability of recycled poly(ethylene terephthalate) (R-PET) for 3D-printing applications was... more The suitability of recycled poly(ethylene terephthalate) (R-PET) for 3D-printing applications was evaluated by studying the melt flow characteristics of the polymer. R-PET is known to experience significant deterioration in its mechanical properties when recycled due to molecular weight loss that results from reprocessing. Lower molecular weight hinders R-PET from being 3D-printable due to low viscosity and melt strength. The hypothesis was that R-PET can be modified with reasonable effort and resources to a 3D-printable thermoplastic if the low viscosity problem is tackled. Higher viscosity will enhance both the melt strength and the melt flow characteristic of the polymer, making it more suitable for processing and 3D printing. Reactive extrusion was selected as the method for modifying the polymer to achieve the objective via a coupling reaction with chain extender PMDA (pyromellitic dianhydride). A decrease in the melt flow index (MFI) from 90 to 1.2 (g/10 min) was recorded when...
Pollutants
One of the main reasons for air pollution is industrial plants releasing huge amounts of air poll... more One of the main reasons for air pollution is industrial plants releasing huge amounts of air pollutants in the form of gas emissions. The different chemical pollutants and their corresponding levels present in these emissions, and their proximity to the industrial source, have serious effects on the nearby ecosystems. Some of the industrial nuisances include noise, smoke, dirt, dust, odor and noxious gases, which have to be minimized (if possible, eliminated), especially if the location is desired to be used as a community site. When choosing locations at which to build either new industrial plants or new community sites, software can be used to assess both the short-term and long-term concentration profiles of the various detrimental air pollutants. In this study, the AERMOD model was used to find an optimal location to build a new plant in Toledo, Ohio, USA. Simulations were performed to study the pollutant emissions and their dispersion patterns for four different geographic loca...
The study is motivated by the quality degradation of groundwater with emphasis on salinity betwee... more The study is motivated by the quality degradation of groundwater with emphasis on salinity between 2012 and 2018 in an aquifer, namely Azarshahr aquifer, located in Western Asia (a case of north-west of Iran), adjacent to Lake Urmia. The groundwater of Azarshahr plain in the south-east, namely, the nutritional zone of the plain, has a low amount of salts (0.7–18.06 mg/L), but by moving to the north-west and west of the plain, which is the location of the outflow of water, the concentration of salts is significantly increased (35.42–87.5 mg/L). Ca–Cl has the cardinal influence on quality of water, making it different from the common type of fresh waters in Iran (Ca–HCO3). High concentrations of SO42−, Cl−, and Na+ detected in almost all the water samples, which indicates aquifer’s good quality for portable applications. Regarding agricultural applications, from 2012 to 2018, the percentage of samples in the good class of C2S1 has been reduced by 35%, which could also be a further ind...
Advances in Civil Engineering, 2019
This study aimed to explore the safe and efficient top-coal caving mining under thin topsoil of s... more This study aimed to explore the safe and efficient top-coal caving mining under thin topsoil of shallow coal seam (SCS) and realize the optimization of hydraulic support. Numerical simulation and theoretical analysis were used to reveal the stress distribution of the topsoil, the structure characteristics of the main roof blocks, and the development of the roof subsidence convergence. Step subsidence of the initial fractured main roof after sliding destabilization frequently existed, which seriously threatened the safety of the hydraulic supports. Hence, a mechanical model of the main roof blocks, where the topsoil thickness was less than the minimum height of the unloading arch, was established, and the mechanical criterion of the stability was achieved. The working resistance of the hydraulic support was calculated, and the reasonable type was optimized so as to avoid crushing accident. Findings of the present analysis indicated that the hydraulic support optimization was mainly a...
Environmental Engineering and Management Journal, 2016
A new simple empirical model is proposed to describe the waste sludge volumetric flow rate in the... more A new simple empirical model is proposed to describe the waste sludge volumetric flow rate in the steady-state completely mixed activated sludge process. The model is derived based on the nonlinear regression analysis by using the Richardson's extrapolation method and the Levenberg-Marquardt algorithm. The application of the model has been explored for a wide range of eleven fundamental biological design variables and tested against a total of 1500 additional computational scenarios and real wastewater plant data. All predictions are proven to be satisfactory with very high determination coefficients of about 0.97 and 0.99, respectively, for the forecast of waste sludge flow rate. Compared with the theoretical approach, the proposed model offers a quite simple and practical mathematical structure incorporating easily obtainable parameters, which are routinely ascertained in the activated sludge-based treatment plants. Besides obviating the need for time-consuming theoretical procedure, the developed equation facilitates the calculations and can be used for any distinct cases of waste sludge withdrawal. Computational results demonstrate that the proposed equation is accurate enough to be used in estimation of waste sludge production and sufficiently simple to be used with a hand-held calculator.
Journal of Environmental Health Science and Engineering, 2019
Background Azo dyes represent the most commonly used group of dyes in the textile industry. These... more Background Azo dyes represent the most commonly used group of dyes in the textile industry. These organic dyes are mainly resistant to biodegradation and may exhibit toxic and carcinogenic properties. The purpose of this study was to investigate the effects of doping zinc oxide (ZnO) nanoparticles (NPs) with transition metals (silver, manganese, and copper) on the photocatalytic efficiency of ZnO NPs in the removal of Direct Blue 15 dye from aqueous environments under ultraviolet (UV) radiation and visible light irradiation. Methods One or two metals were used for doping the NPs. In total, seven types of undoped and transition metal-doped NPs were synthesized using the thermal solvent method with ZnO precursors and transition metal salts. The characteristics of the synthesized NPs were determined based on the scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Xray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), atomic force microscopy (AFM), and zeta potential measurements. Results The produced ZnO NPs did not exhibit any particular photocatalytic activities under UV radiation and visible light irradiation. The highest removal efficiency under UV radiation was about 74% in the presence of silver-doped ZnO NPs, while the maximum efficiency under visible light was 70% in the presence of copper-doped ZnO NPs. The lowest removal efficiency Highlights • Transition metal-doped ZnO NPs was used for photocatalytic removal of Direct Blue 15 dye. • Photocatalytic activity of ZnO NPs was improved after doping with Ag, Mn, and Cu. • SEM, XRD, FTIR, and AFM corroborated the synthesis of transition metal-doped NPs. • Photocatalysis using Ag-doped ZnO NPs could degrade 74% of dye under UV radiation. • About 70% of dye could be removed using Cu-doped ZnO NPs under visible light.
Environmental Engineering and Management Journal, 2011
Recovery of residual ammonium nitrogen (NH 4 +-N) from dissolved air flotation (DAF) pretreated p... more Recovery of residual ammonium nitrogen (NH 4 +-N) from dissolved air flotation (DAF) pretreated poultry slaughterhouse wastewater was studied by means of magnesium ammonium phosphate hexahydrate (MgNH 4 PO 4 .6H 2 O, MAP) precipitation in a lab-scale batch study. The maximum recovery values were obtained as 80.2%, 97.1% and 53.6% with the addition of MgCl 2 .6H 2 O + KH 2 PO 4 , NaH 2 PO 4 .2H 2 O + MgSO 4 .7H 2 O, and MgOHCO 3 + 85% H 3 PO 4 at pH 9.5, respectively. Based on the physicochemical findings, subsequent batch experiments were conducted at pH 9.5 for eight different molar ratios (Mg 2+ :NH 4 +-N:PO 4-N removed for the proposed application. The rate of reaction was found to be very fast, being completed within minutes, and cost effective in large-scale poultry slaughterhouse facilities.
Issue 4, 2017
This research examined the genotoxic activity in the seawater of Asin Bay (Gulf of Gulluk) locate... more This research examined the genotoxic activity in the seawater of Asin Bay (Gulf of Gulluk) located in Mugla, Turkey, Aegean coast of Turkey. Genotoxic activities of 66 raw samples, taken from 17 different stations in the spring and summer seasons of the year 2013, were determined by using in vitro mutagenicity assay SOS chromotest with Escherichia coli PQ37 strain bacteria activities. In the applied procedure, β-galactosidase (β-gal) activity, alkaline phosphatase (AP) activity, and different solvent controls were taken into account to generate reliable results in terms of the corrected induction factors (CIF) used as a quantitative measure of genotoxic activity level. The SOS chromotest procedure was simply and rapidly performed as an early assay to explore for whether a potential genotoxic activity was presence in the in the seawater of Asin Bay (Gulf of Gulluk) with no special measuring devices except a microplate reader. The implemented assay was successfully completed within on...
Issue 2, 2017
The production and use of biofuels such as ethanol have been the target of intensive research. On... more The production and use of biofuels such as ethanol have been the target of intensive research. One source of ethanol is corn, which is abundant in many countries. In producing ethanol from corn, an assessment of the environmental impact of the process is needed. This study intends to provide insight into benzene emitted from a proposed biofuel plant, its dispersion behavior, and the effects it may have on the immediate environment. Three-season (January, April, and June) dispersion results of benzene emissions from the proposed ethanol-producing facility are evaluated by using the CALPUFF modelling system. Within the framework of the CALPro software, ambient benzene concentrations are modelled over a 24-hour period of exposure by considering the impact of pollutant transformation and removal, and meteorological factors such as wind direction and speed, and temperature. Simulations are performed for the plant area located in Farewell, Oshawa, Ontario, based on the emission and meteor...
Process Safety and Environmental Protection, 2019
Water Science and Technology, 2015
The present paper deals with a complete batch adsorption study of 4-nitrophenol (4NP) from aqueou... more The present paper deals with a complete batch adsorption study of 4-nitrophenol (4NP) from aqueous solution onto activated carbon prepared from Acacia glauca sawdust (AGAC). The surface area of the adsorbent determined by methylene blue method is found to be 311.20 m2/g. The optimum dose of adsorbent was found to be 2 g/l with 4NP uptake of 25.93 mg/g. The equilibrium time was found to be 30 minutes with the percentage removal of 96.40 at the initial concentration of 50 ppm. The maximum removal of 98.94% was found to be at pH of 6. The equilibrium and kinetic study revealed that the Radke–Prausnitz isotherm and pseudo second order kinetics model fitted the respective data well. In the thermodynamic study, the negative value of Gibbs free energy change (−26.38 kJ/mol at 30°C) and enthalpy change (−6.12 kJ/mol) showed the spontaneous and exothermic nature of the adsorption process.
Journal of Cleaner Production, 2017
Struvite precipitation is widely used as an established and promising physicochemical treatment m... more Struvite precipitation is widely used as an established and promising physicochemical treatment method due to its higher effectiveness for removing and recovering excess nitrogen and phosphorus from wastewater, and production of a beneficial byproduct at the end of the process. However, the majority of the literature focus not on the economic aspects of the process, but rather on the effect of different chemical combinations and changing operating conditions. In order to fulfill this gap, this study aims at a comprehensive feasibility analysis of struvite recovery process for a full-scale fertilizer production industry with a 500 m 3 /day capacity. For quantitative assessment, the experimental conditions and chemical combinations that will allow the receiving environment discharge standard for ammonium nitrogen are optimized by taking into account a large number of economic and operating parameters. The effect of change in the struvite sale price on the profit share is examined for the optimum conditions, and the investment and operating costs are calculated by getting the latest up-to-date values from the market. It is determined that when the struvite sale price is raised to 560 V/ton, the facility will obtain a net profit of V445.62/day, and be able to pay for itself in approximately six years. The findings of this study corroborate the economic feasibility of struvite recovery process as a clean and eco-friendly technology at the plant level for a sustainable nutrient management. Clearly, it appears likely that the struvite precipitation method will become more widespread in the future as an effective and nonpolluting process.
Chemical Industry and Chemical Engineering Quarterly, 2017
The study investigated the pretreatment of real paracetamol (PCT) wastewater of a pharmaceutical ... more The study investigated the pretreatment of real paracetamol (PCT) wastewater of a pharmaceutical industry by Fenton process. At the best experimental conditions (COD/H2O2 = 1/1, Fe+2/H2O2 = 1/70, settling method:centrifuging, pH 6 at settling step), 92.7, 92.7, 95.5, 99.1, 99.9 and 99.4% of chemical oxygen demand (COD), total organic carbon (TOC), 5-day biological oxygen demand (BOD5), PCT, para-amino phenol (PAP) and aniline were removed, respectively. Changes in the concentrations of these parameters were also investigated for both oxidation and settling steps of Fenton process. It was found that COD and TOC were removed at the settling step (precipitation) whereas PCT, PAP and aniline were removed at the oxidation step. Mass balance calculations were also studied to show the mass distributions of COD in different phases (gas + foam, effluent and sludge). Fenton process was found as an effective method for the pretreatment of real PCT wastewater for discharging in a determined col...
Chemical Industry and Chemical Engineering Quarterly, 2017
The operation conditions for the implementation of the Fenton process are of utmost importance be... more The operation conditions for the implementation of the Fenton process are of utmost importance because there are problems related to the proportion of H2O2 dosage to COD and Fe2+ dosage to the specified H2O2 amount. The relevant lite-rature shows that COD/H2O2 ratios range between 0.0084 and 113.9. Similarly, the COD/Fe2+ ratio varies between 0.079 and 292.6, while the H2O2/Fe2+ ratio varies between 0.09 and 287. Moreover, the ratio of the maximum value to the minimum value used in the operations on the basis of COD is 13560 for COD/ /H2O2 (0.0084-113.9), 2210 for COD/Fe2+ (0.079-174.7), and finally 3190 for H2O2/Fe2+ (0,09-287). The aim of this study was to re-evaluate these values that significantly differ from each other with specific emphasis on textile wastewater and considering stoichiometric ratios. Results showed that values ranging between 0.43 and 4.0 for COD/H2O2 and those ranging between 0.75 and 3.0 for H2O2/Fe2+ are more suitable. The results showed that in a Fenton pr...
Engineering Structures, 2015
Worldwide ageing infrastructures which are vulnerable to seismic lateral loads and located in hig... more Worldwide ageing infrastructures which are vulnerable to seismic lateral loads and located in high seismicity regions have arrested the interest of many researchers to find alternative materials and techniques to strengthen in bending and shear, for example reinforced concrete (RC) beams, slabs, columns, etc. There are several strengthening/repair techniques and materials in literature. Although the method of strengthening concrete structures with fiber reinforced polymers (FRP) is a relatively new technique, it has existed for more than two decades. In this context, several confinement models have been developed for FRP-confined concrete for the prediction of stress-strain response and several researchers have developed various constitutive models to measure the increase in the axial strength of concrete due to the confinement effect of FRP laminates. In this study, RC columns wrapped with carbon FRP (CFRP) considering some existing confinement models in the literature have been investigated. Moreover, based on the experimental data set in the literature, a new artificial intelligence-based algorithm (a Mamdani-type fuzzy inference system) was implemented to model the strength enhancement of CFRP confined RC columns using fuzzy logic methodology. Fuzzy logic predicted results were compared with the outputs of a non-linear regression analysis-based exponential model derived in the scope of the present work. The best predictive performances of the models were assessed by means of various descriptive statistical indicators. The comparison of the proposed prognostic approach with existing empirical and experimental data exhibits a very good precision of the developed artificial intelligence-based model in predicting the lateral confinement coefficient in CFRP wrapped RC columns.
Journal of Environmental Health Science and Engineering, 2013
The aim of this study was to investigate the performance of a two-stage fluidized bed reactor (FB... more The aim of this study was to investigate the performance of a two-stage fluidized bed reactor (FBR) system for the post-treatment of secondary wastewater treatment plant effluents (Shahrak Gharb, Tehran, Iran). The proposed treatment scheme was evaluated using pilot-scale reactors (106-L of capacity) filled with PVC as the fluidized bed (first stage) and gravel for the filtration purpose (second stage). Aluminum sulfate (30 mg/L) and chlorine (1 mg/L) were used for the coagulation and disinfection of the effluent, respectively. To monitor the performance of the FBR system, variation of several parameters (biochemical oxygen demand (BOD5), chemical oxygen demand (COD), turbidity, total phosphorous, total coliform and fecal coliform) were monitored in the effluent wastewater samples. The results showed that the proposed system could effectively reduce BOD5 and COD below 1.95 and 4.06 mg/L, respectively. Turbidity of the effluent could be achieved below 0.75 NTU, which was lower than t...
Waste Management, 2011
One-dimensional (1D) advection-dispersion transport modeling was conducted as a conceptual approa... more One-dimensional (1D) advection-dispersion transport modeling was conducted as a conceptual approach for the estimation of the transport parameters of fourteen different phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and three different inorganic contaminants (Cu, Zn, Fe) migrating downward through the several liner systems. Four identical pilot-scale landfill reactors (0.25 m 3) with different composite liners (R1: 0.10 + 0.10 m of compacted clay liner (CCL), L e = 0.20 m, k e = 1 Â 10 À8 m/s, R2: 0.002-m-thick damaged high-density polyethylene (HDPE) geomembrane overlying 0.10 + 0.10 m of CCL, L e = 0.20 m, k e = 1 Â 10 À8 m/s, R3: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick bentonite layer encapsulated between 0.10 + 0.10 m CCL, L e = 0.22 m, k e = 1 Â 10 À8 m/s, R4: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick zeolite layer encapsulated between 0.10 + 0.10 m CCL, L e = 0.22 m, k e = 4.24 Â 10 À7 m/s) were simultaneously run for a period of about 540 days to investigate the nature of diffusive and advective transport of the selected organic and inorganic contaminants. The results of 1D transport model showed that the highest molecular diffusion coefficients, ranging from 4.77 Â 10 À10 to 10.67 Â 10 À10 m 2 /s, were estimated for phenol (R4), 2-MP (R1), 2,4-DNP (R2), 2,4-DCP (R1), 2,6-DCP (R2), 2,4,5-TCP (R2) and 2,3,4,6-TeCP (R1). For all reactors, dispersion coefficients of Cu, ranging from 3.47 Â 10 À6 m 2 /s to 5.37 Â 10 À2 m 2 /s, was determined to be higher than others obtained for Zn and Fe. Average molecular diffusion coefficients of phenolic compounds were estimated to be about 5.64 Â 10 À10 m 2 /s, 5.37 Â 10 À10 m 2 /s, 2.69 Â 10 À10 m 2 /s and 3.29 Â 10 À10 m 2 /s for R1, R2, R3 and R4 systems, respectively. The findings of this study clearly indicated that about 35-50% of transport of phenolic compounds to the groundwater is believed to be prevented with the use of zeolite and bentonite materials in landfill liner systems.
Desalination and Water Treatment, 2014
A concentrate stream is generated by the application of nanofiltration (NF) membranes in wastewat... more A concentrate stream is generated by the application of nanofiltration (NF) membranes in wastewater reuse. Due to the high concentrations of pollutants, disposal of NF concentrates is an important problem. In this study, ozonation and anaerobic treatment processes were performed to treat cotton dyeing textile mill wastewater NF concentrate. After ozonation, the concentration of biochemical oxygen demand (BOD 5) increased while dissolved chemical oxygen demand (DCOD) decreased. Thus, biodegradability of the concentrate was increased by the ozonation process. The average removal efficiencies of DCOD, BOD 5 , and sulfate (SO 2À 4) in the anaerobic process were achieved about 72, 76, and 68%, respectively. These results indicated that the combination of ozonation and anaerobic treatment showed a remarkable performance for the removal of pollutants from NF concentrate.
Journal of Hazardous Materials, 2009
A three factor, three-level Box-Behnken experimental design combining with response surface model... more A three factor, three-level Box-Behnken experimental design combining with response surface modeling (RSM) and quadratic programming (QP) was employed for maximizing Pb(II) removal from aqueous solution by Antep pistachio (Pistacia vera L.) shells based on 17 different experimental data obtained in a lab-scale batch study. Three independent variables (initial pH of solution (pH 0) ranging from 2.0 to 5.5, initial concentration of Pb(II) ions (C 0) ranging from 5 to 50 ppm, and contact time (t C) ranging from 5 to 120 min) were consecutively coded as x 1 , x 2 and x 3 at three levels (−1, 0 and 1), and a second-order polynomial regression equation was then derived to predict responses. The significance of independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95% confidence limits (˛= 0.05). The standardized effects of the independent variables and their interactions on the dependent variable were also investigated by preparing a Pareto chart. The optimum values of the selected variables were obtained by solving the quadratic regression model, as well as by analysing the response surface contour plots. The optimum coded values of three test variables were computed as x 1 = 0.125, x 2 = 0.707, and x 3 = 0.107 by using a LOQO/AMPL optimization algorithm. The experimental conditions at this global point were determined to be pH 0 = 3.97, C 0 = 43.4 ppm, and t C = 68.7 min, and the corresponding Pb(II) removal efficiency was found to be about 100%.
Journal of Hazardous Materials, 2009
A comprehensive analysis of Turkish antibiotic data was conducted to evaluate potential environme... more A comprehensive analysis of Turkish antibiotic data was conducted to evaluate potential environmental risks associated with antibiotic consumption in Turkey for year 2007. Antibiotics were defined for systemic use or group J01 of the WHO Anatomical Therapeutic Chemical (ATC) classification system. Total emissions and prescriptions for each ATC group were classified separately into 17 different J01 categories and three forms of medication (capsule/tablets, injectables and suspensions). Capsules and tablets were found as the most emitted form of medication in year 2007, with a total emission rate of about 585.5 tons/year (76%). Total antibiotic emission rates including all forms of medications were determined to be about 664.2 tons/year (86%) and 110.1 tons/year (14%) for adult and pediatric patients, respectively. An environmental risk assessment of 8 human antibiotics was conducted according to the EU draft guidance (CEC/III/5504/94, draft 6, version 4) and the risk was indicated by the ratio of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) for the aquatic environment. Available acute and chronic toxicity data were collected from the open peer-reviewed literature to derive PNEC. Risk quotients (PEC/PNEC) were then calculated for 8 pharmaceutical substances. PEC/PNEC ratio exceeded 1.0 for -lactams (cephalosporins and penicillins), fluoroquinolones, macrolides and aminoglycosides. The findings of this study concluded that the release of these compounds from wastewater treatment plants may potentially be of an important environmental concern based on today's use of antibiotics in Turkey.
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Papers by Kaan Yetilmezsoy