Environmental Engineering / Çevre Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4321

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Now showing 1 - 7 of 7

Citation - WoS: 25
Citation - Scopus: 32
Arsenite Removal From Groundwater in a Batch Electrocoagulation Process: Optimization Through Response Surface Methodology
(Taylor & Francis, 2019) Şık, Emrah; Gören, Ayşegül Yağmur; Demirbaş, Erhan; Kobya, Mehmet; Öncel, Mehmet Salim; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
In this study, influences of seven process variables such as initial pH (pH(i)), applied current (i), operating time (t(EC)), initial As(III) concentration (C-o), diameter of Fe ball anode (d(p)), column height in the electrocoagulation (EC) reactor (h) and airflow rate (Q(air)) for removal of As(III) from groundwater by a new air-fed fixed-bed EC reactor were evaluated with a response surface methodology (RSM). The proposed quadratic model fitted very well with the experimental data for the responses. The removal efficiencies and operating costs were determined to be 99% and 0.01 $/m(3) at the optimum operating conditions (a pH(i) of 8.5, 0.05 A, 4.94 min, d(p) of 9.24 mm, h of 7.49 cm, Q(air) of 9.98 L/min for 50 mu g/L). This study clearly showed that the RSM in the EC process was a very suitable method to optimize the operating conditions at the target value of effluent As(III) concentration (10 mu g/L) while keeping the operating cost to minimal and maximize the removal efficiency.
Citation - WoS: 12
Citation - Scopus: 14
Assessment and Improvement of Indoor Environmental Quality in a Primary School
(Taylor and Francis Ltd., 2017-02) Ekren, Orhan; Karadeniz, Ziya Haktan; Atmaca, İbrahim; Ugranlı Çiçek, Tuğba; Sofuoğlu, Sait Cemil; Toksoy, Macit; 03.07. Department of Environmental Engineering; 03.06. Department of Energy Systems Engineering; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
This study reports levels of indoor environmental quality variables before and after installation of heat recovery ventilation in a primary school located in an urban area in Izmir, Turkey. A CO2-based modeling was performed to determine the required flow rates that would comply with an international ventilation standard, followed by computational fluid dynamics modeling for best airflow distribution in a classroom. Temperature, CO2, PM2.5, and total volatile organic compounds were found at undesired levels, among which relative humidity, CO2, and PM2.5 were improved after the intervention. Reductions in the mean and maximum concentrations were 29% and 68% for CO2 and 29% and 46% for PM2.5. This intervention study was a part of the city-wide main project that aimed to increase awareness of the students and their families, teachers, and staff regarding importance of indoor environmental quality in both at school and home due to its possible effects on children's health and academic performance, one of the major challenges of today's societies all around the globe.
Citation - WoS: 1
Dynamics of Co2 Consumption, and Biomass and Lipid Carbon Production During Photobioreactor Cultivation of the Diatom Cyclotella
(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2023) Ökten, Hatice
Understanding of CO2 delivery and consumption dynamics in algal photobioreactors are critical to unravel microalgae’s full potential for bioproduct generation and carbon capture from flue gas streams. This study aims to expand our current understanding by cultivating the diatom Cyclotella under controlled process conditions of a bubble column photobioreactor and analyzing CO2 consumption dynamics in real time using results from an online CO2 sensor connected to the reactor exhaust. Two sets of experiments were conducted: they served to contrast the influence of silicon and nitrate (Si&N colimitation) and Si limitation, and the light availability, respectively. CO2 consumption was calculated based on the mass balance around the reactor inlet and outlet gas streams. Biomass samples and lipid extracts were analyzed for carbon (C) content to determine biomass-C and lipid-C concentrations. The outlet CO2 concentrations varied significantly with cultivation time and process conditions. More than 15% to 65% of the CO2 introduced left the reactor in the exhaust at any instance based on the set CO2 transfer rates. The highest average daily capturing efficiency was 60%. Nutrient limitation regimes imposed generated unique CO2 consumption profiles undiscernible by the biomass-C analysis, i.e. unlike Si limitation, N limitation had more immediate detrimental effects on C consumption. Final biomass-C concentration increased with increasing N and light availability, 275 mg/L vs. 336 mg/L, and 270 mg/L vs. 501 mg/L, respectively. Biomass-C based capturing efficiency approximations resulted in 20% to 40% underestimation. Under Si-limited conditions, the higher light intensity increased the final lipid-C to biomass-C ratio by two times (from 20% to 40%) and the final lipid-C concentration and peak productivity by four times (from 56 mg/L to 216 mg/L, from 7 to 30 mg/L-day, respectively). This study demonstrates online exhaust CO2 concentration-based analysis’s unique capabilities for assessing carbon availability and capture, organic-C production, and its diversion to biomass and lipid production.
Citation - WoS: 14
Citation - Scopus: 22
Forecasting Ambient Air So2 Concentrations Using Artificial Neural Networks
(Taylor and Francis Ltd., 2006-07) Sofuoğlu, Sait Cemil; Sofuoğlu, Aysun; Birgili, Savaş; Tayfur, Gökmen; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
An Artificial Neural Networks (ANNs) model is constructed to forecast SO 2 concentrations in Izmir air. The model uses meteorological variables (wind speed and temperature) and measured particulate matter concentrations as input variables. The correlation coefficient between observed and forecasted concentrations is 0.94 for the network that uses all three variables as input parameters. The root mean square error value of the model is 3.60 g/mt 3 . Considering the limited number of available input variables, model performances show that ANNs are a promising method of modeling to forecast ambient air SO 2 concentrations in Izmir.
Citation - WoS: 4
Citation - Scopus: 4
A Hybrid Process for 2,4-Dichlorophenoxy Acetic Acid Herbicidal Treatment and Its Microbial Identification by Maldi-Tof Mass Spectrometry
(Taylor and Francis Ltd., 2020-03) Doğdu Okçu, Gamze; Ökten, Hatice Eser; Yalçuk, Arda; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The feasibility of coupling photocatalysis and a biological treatment to remove a herbicide–2,4-dichlorophenoxy acetic acid (2,4-D)–from pure water was examined using batch experiments following three protocols: aerated (A-BR) and non-aerated biodegradation (NA-BR) alone, and intimately combined photodegradation and biodegradation (P-B). In view of a subsequent biological treatment, 15 and 180 min irradiation times were chosen in accordance with spectrophotometric and LC-MS/MS results that indicated the decrease in the COD/TOC ratio during photocatalysis. Pre-treatment led to a quick decrease in concentration of 2,4-D and COD during the biological process: a 78.79 ± 0.30% COD removal and 38.23 ± 3.12% 2,4-D elimination was measured after 5760 min in A-BR, and 80.89 ± 0.81% COD and 81.36 ± 1.37% 2,4-D removal was achieved after 2880 min in P-B. For species identification using matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF)-TOF/MS equipment, Aeromonas eucrenophila, Stenotrophomonas acidaminiphila, Ralstonia pickettii, Sphingobacterium multivorum and Acinetobacter towneri were identified with high accuracy, and they play important roles in the degradation of 2,4-D.
Citation - WoS: 12
Citation - Scopus: 14
Remote Sensing-Based Monitoring and Evaluation of the Basin-Wise Dynamics of Terrestrial Water and Groundwater Storage Fluctuations
(Springer, 2023) Khorrami, Behnam; Gündüz, Orhan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The recent dynamics of terrestrial water storage (TWS) and groundwater storage (GWS) fluctuations were investigated based on the Gravity Recovery And Climate Experiment (GRACE) observations over 25 basins of Türkiye. Coarse-resolution GRACE estimates were downscaled based on the Random Forest algorithm. The impacts of precipitation (P) and evapotranspiration (ET) on the variations of water storage were also assessed. The findings demonstrated good performance for the RF model in simulating finer resolution estimates of TWS. The results indicated a diminishing trend of TWS and its hydrologic components over all the basins from 2003 to 2020. The Doğu Akdeniz Basin with the annually decreasing TWS and GWS of 1.15cm/yr and 1.10cm/yr was the most critical basin of Türkiye. The least storage loss was observed in the Batı Karadeniz Basin with the annual TWS and GWS loss of 0.38cm/yr and 0.45cm/yr , respectively. Based on the results, Türkiye has lost, on average, an estimated 5.16km3/yr and 4.09km3/yr of its TWS and GWS, respectively, which are equivalent to the total storage loss of 92.88km3 and 73.62km3 of TWS and GWS during the last 18 years. The results also indicated that P and ET interact differently with the variations of TWS and GWS. The net water flux was revealed to be partially correlated with the total water storage fluctuations, suggesting the governing role of other deriving forces particularly the anthropogenic factors in the spatiotemporal variations of Türkiye’s water storage; therefore, a sector-specific analysis of the water storage variations is crucial for the country, particularly by concentrating more on the dynamics of GWS. Graphical Abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
Citation - WoS: 58
Citation - Scopus: 72
Utilization of Municipal Plastic and Wood Waste in Industrial Manufacturing of Wood Plastic Composites
(Springer Verlag, 2020-10) Başalp, Dildare; Tıhmınlıoğlu, Funda; Sofuoğlu, Sait Cemil; İnal, Fikret; Sofuoğlu, Aysun; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
In this study, Wood Plastic Composites (WPCs) were produced from post-consumer bulky wastes of recycled plastic and wood in order to minimize waste, decrease environmental effects of plastics, reserve natural resources, and support circular economy for sustainable production and consumption. Five different types of polypropylene (PP) or polyethylene (PE) based recycled plastics and wood obtained from urban household bulky wastes were used in the production of recycled WPC composites, r-WPCs. Virgin WPC (v-WPC) and r-WPC compounds were prepared with wood flour (WF) and maleic anhydride grafted compatibilizer (MAPP or MAPE) to evaluate the effect of recycled polymer type and compatibilizer on the mechanical properties. It was found that tensile strength properties of r-WPCs produced from recycled PP (r-PP) were higher than that of the r-WPCs produced from mixed polyolefins and recycled PE. r-WPCs containing anti-oxidants, UV stabilizers, and compatibilizer with different WF compositions were produced from only recycled garden fraction PP (PPFGF) to determine the optimum composition and processing temperature for pilot scale manufacturing of r-WPCs. Based on tensile, impact, flexural, and water sorption properties of r-WPC compounds with different formulations, the optimum conditions of r-WPC compounds for industrial manufacturing process were determined. Surface morphology of fractured surfaces as well as tensile, flexural and density results of r-WPC compounds revealed the enhancement effect of MAPP on interfacial adhesion in r-WPCs. r-WPC products (crates and table/chair legs) based on bulky wastes were produced using an injection molding process at industrial scale by using 30 wt% WF-filled r-WPC compound. This study demonstrated that r-WPC compounds from recycled bulky plastic and wood wastes can be used as a potential raw material in plastic as well as WPC industry, contributing to circular economy. Graphic

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