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Using MODIS derived aerosol optical depth to estimate ground-level PM(2.5) concentrations over Turkey

Zeydan, Özgür | Wang, Yuhang

Article | 2019 | ATMOSPHERIC POLLUTION RESEARCH10 ( 5 ) , pp.1565 - 1576

Satellite based particulate matter (PM) pollution monitoring on a regional basis is of importance due in part to the adverse health effects of PM. In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) derived aerosol optical depth (AOD) data at 3 km and 10 km resolutions from both Terra and Aqua satellites were used, in conjunction with the surface in situ data, to improve the regional distribution of ground-level PM2.5 over Turkey. Five years (2011-2015) of heating season's (15th October to 14th May) in situ PM2.5 measurements from 7 monitoring stations in Ankara and 3 years (2013-2015) of the same data from 13 monit . . .oring stations in Marmara Region were used. Linear and non-linear regression models were used to find the relationship between PM2.5 and AOD data. To improve the correlations between PM2.5 and AOD, the data points affected by free tropospheric long-range transport were removed from the analysis via back trajectory modeling analysis since long-range transport affects AOD more readily than surface PM2.5 data. Using non-linear models with the addition of meteorological parameters such as height of planetary boundary layer, surface temperature and surface wind speed improved the correlations significantly. The best non-linear model can explain 61% (n = 37, R-2 = 0.61, p < 0.001, RMSE = 0.337 mu g/m(3)) of PM2.5 variations at the Edirne Kesan site. It was found that Terra worked better than Aqua. Furthermore, 10-km aerosol products gave better correlations with PM2.5 as compared to the 3-km products. With the aid of spatiotemporal model, PM(2.5 )distribution maps are created for the first time for Turkey Daha fazlası Daha az

Separation of Cd(II) from aqueous solutions by a new consecutive process consisting of supported liquid membrane and electrodialysis

Altın, Süreyya | Altın, Ahmet

Article | 2019 | Journal of Electrochemical Science and Technology10 ( 1 ) , pp.14 - 21

Supported liquid membrane process usually is used for recovering or enrichment of valuable metals in the industrial wastewater. But, even if the metals in the wastewater was separated with high chemical selectivity, it cannot be enough concentrated since separation performance of supported liquid membrane (SLM) process is limited by concentration gradient between feed solution and stripping solution. If metal concentration in the stripping solution to be enough low, transport of metal through membrane can be accomplishment constantly. Therefore, Electrodialysis (ED) has been placed after SLM process and the stripping solution of SLM . . . was used as the feed solution for the ED process. Transport of ions in the solutions is successfully performed by ED process. Thus, the metal concentration in the stripping solution does not rise as to stop ion transport. Besides, valuable metals easily are concentrated by ED process for re-use. In this study, effects of operation parameters like initial Cd(II) concentration, HCl concentration in the feed solution of SLM and applied voltage are investigated on separation efficiency, flux and permeability of the both processes. As the feed solution concentration increased, all performance values has increased. When initial concentration of 100 mg/L is used, separation performances (SP) are 55% and 70%, for SLM and consecutive process, respectively. The best HCl concentration in the feed solution of SLM has determined as 2 M, in this conditions SP are 64% and 72%, for SLM and consecutive process, respectively. With increased of applied voltage on ED process, SP of the consecutive process has been raised from 72% to 83%. According to the obtained experimental data, consecutive process has better separation performance than SLM. When the separation performances of both processes were compared for the same operating conditions, it was determined higher the separation efficiency, permeability and flux values of the consecutive process, 8%, 9% and %10.6, respectively. Consequently, the use of the consecutive process increases the performance efficiency of both processes. The consecutive process studied has quite a good chemical separation efficiency, and enrichment capability. Moreover, this process requires few water and energy. © 2019, Korean Electrochemical Society. All rights reserved Daha fazlası Daha az

Impacts of sludge retention time on membrane fouling in thermophilic MBR

İnce, Mine | Topaloğlu, Alikemal

Article | 2018 | Membrane Water Treatment9 ( 4 ) , pp.245 - 253

The aim of this study is to investigate the membrane fouling in a thermophilic membrane bioreactor (TMBR) operated different sludge retention times (SRTs). For this purpose, TMBR was operated at four different SRTs (10, 30, 60 and 100 days). Specific cake resistance (?), cake resistance, gel resistance, total resistance, MFI (modified fouling index) and FDR (flux decrease ratio) were calculated for all SRTs. It was observed that flux in the membrane increases with rising SRT although the sludge concentrations in the TMBR increased. The steady state flux was found to be 31.78; 34.70; 39.60 and 43.70 LMH (Liter/m2/h) for the SRTs of 1 . . .0, 30, 60 and 100 days respectively. The concentrations of extracellular polymeric substance (EPS) and soluble microbial product (SMP) decreased with increasing SRT. The membrane fouling rate was higher at shorter SRT and the highest fouling rate appeared at an SRT of 10 d. Both the sludge cake layer and gel layer had contribution to the fouling resistance, but the gel layer resistance value was dominant in all SRTs. © 2018 Techno-Press, Ltd Daha fazlası Daha az

The efficient combustion of o-xylene in a Knudsen controlled catalytic membrane reactor

Yıldırım, Yılmaz | Hughes, Ronald

Article | 2002 | PROCESS SAFETY AND ENVIRONMENTAL PROTECTION80 ( B3 ) , pp.159 - 164

Catalytic inorganic membrane preparation and the catalytic oxidation of o-xylene contained in air streams on catalytic membrane tubes are presented in this study. Boehmite prepared sols were deposited onto porous alumina tubes from the outside using a filtration coating technique. The coatings were characterized by nitrogen gas permeations at the same temperatures used for the o-xylene experiments. Single gas permeabilities indicated a best separation factor for the modified membrane for H-2/N-2 of 3.6, which is very close to the Knudsen value. Pt loading was estimated as 1.6%w/w based on membrane material weight by using both weigh . . .ing and atomic absorption spectrophotometry (AAS) methods. O-ylene catalytic oxidation of o-xylene contained in air streams with concentrations between 0.146-0.220% (v/v) was carried out in a catalytic membrane reactor at temperatures between 150-290degreesC and 97% conversion was achieved for 0.146% o-xylene in air at a temperature of 285degreesC Daha fazlası Daha az

The effects of diluents on sodium ion transport through bulk liquid membrane with crown ether carriers

Altın, Süreyya | Peker, İbrahim | Demircioğlu, Nesli

Article | 2009 | Polish Journal of Chemistry83 ( 2 ) , pp.275 - 283

In this study, the effects of the different membrane diluents, carriers and variations in the concentrations of the carriers on the sodium ion transport were examined in bulk liquid membrane systems. The kinetic analysis of the sodium ion transport in the liquid membrane was performed through the implementation of two consecutive kinetic equations of first order irreversible reactions and the relevant kinetic parameters (k1, k2a, k2a, Rmax, tmax,) were determined. Toluene, n-hexane, 1-octanol, chloroform and dichloromethane were used as membrane diluents, while 18crown6 (18C6), dicyclohexyl 18crown6 (DC18C6) and dibenzo 18crown6 (DB . . .18C6) were used as carriers. The results reveal that the best sodium ion transport was realized when toluene-dichloromethane (90%-10%) was used as the membrane, and 1.10-3 M DB18C6 was used as the carrier Daha fazlası Daha az

Electrocoagulation in a packed bed reactor-complete treatment of color and cod from real textile wastewater

Tezcan Ün, Ümran | Aytaç, Ersin

Article | 2013 | Journal of Environmental Management123 , pp.113 - 119

This paper deals with the efficiency of electrocoagulation (EC) for the abatement of COD and absorbance (i.e. color) from real textile wastewater using a packed bed electrochemical reactor in a unique design, not previously encountered in the literature for the treatment of textile wastewater by electrocoagulation. The cylindrical iron reactor was used as a cathode while the packed bed formed from wrapped iron wire netting was used as an anode. Various operating parameters, such as current density, initial pH, wastewater recirculation flow rate and continuous flow regime, were examined for intensifying the performance of the process . . .. Also, calculation of electrical energy consumption and the characterization of sludge formed during electrocoagulation have been performed. The initial COD concentration of 1953mg/L was reduced to 61mg/L with a removal efficiency of 96.88%, while the color of the wastewater was almost completely removed. The experimental results, throughout the present study, have indicate that electrocoagulation of textile wastewater using a uniquely designed reactor was very effective and direct dischargeable effluent, complying with legal requirements, was obtained. The XRD analysis of the sludge produced during EC reveals that maghemite (Fe2O3) is the main by-product formed after EC. © 2013 Elsevier Ltd Daha fazlası Daha az

Sorption of acid dyes from aqueous solution by using non-ground ash and slag

Genç, Ayten | Oğuz, Aşkın

Article | 2010 | Desalination264 ( 01.Feb ) , pp.78 - 83

The sorption of two acid dyes (Acid Yellow 99 and Acid Red 183) into locally available industrial waste materials, namely, Granulated Blast Furnace Slag (GBFS) and Furnace Bottom Ash (FBA), has been investigated by performing batch equilibrium experiments with pH, ionic conductivity, initial dye concentration and temperature as variables. The kinetic sorption data indicated that the sorption capacity of GBFS for these dyes was almost zero. On the other hand, the color removal efficiency for FBA could reach 50% depending on the initial dye concentration. It was also found that the kinetics of sorption of Acid Yellow 99 and Acid Red 1 . . .83 onto the surface of FBA at different operating conditions were best described by the Elovich kinetic model. In addition, the adsorption equilibrium data were analyzed using various adsorption isotherm models and the results have shown that the sorption behaviors of the studied dyes could be best described by the Langmuir model. © 2010 Elsevier B.V Daha fazlası Daha az

Dependency of removal efficiency on electrode arrangements in the treatment of oily wastewaters by electrocoagulation

Genç, Ayten | Eryılmaz, Candan

Article | 2017 | Separation Science and Technology (Philadelphia)52 ( 9 ) , pp.1594 - 1601

Turbidity and chemical oxygen demand (COD) removal efficiencies were analyzed depending on electrode layouts by performing electrocoagulation experiments using horizontal and vertical electrochemical cells. Multiple aluminum plate electrodes were placed into different sections of the electrochemical cells. Removal efficiencies at the horizontal electrochemical cell were always higher than the one’s obtained from the vertical electrochemical cell. But the use of vertical electrochemical cell consumed less energy during the electrocoagulation tests. The highest COD removal efficiencies were 97% and 88% in the horizontal and vertical e . . .lectrochemical cells, respectively. However, the energy consumption for COD removal in the horizontal electrochemical cell was 47% higher than the energy consumed in the vertical electrochemical cell. © 2017 Taylor & Francis Daha fazlası Daha az

Cost analysis of plastic solid waste recycling in an urban district in Turkey

Genç, Ayten | Zeydan, Özgür | Saraç, Selin

Article | 2019 | Waste Management and Research37 ( 9 ) , pp.906 - 913

The usage of plastics has exponentially increased in our daily lives over the past 50 years because of its durability, low costs and potential for diverse applications, such as widespread use as disposable items. In this study, first, the recycling cost of plastic wastes has been estimated by using actual data taken from a recycling centre, where plastic solid wastes were collected separately. The total amount of plastic wastes recycled at the centre was approximately 695 tonnes. The operating cost of plastics separation at the recycling centre, the transport of plastic wastes, labouring, maintenance, electricity, insurance and chem . . .ical costs were taken into consideration in the cost evaluation. Accordingly, the unit cost of recycling was calculated as US$0.40 kg-1 of plastic waste. This cost was compared with the predicted plastic recycling cost in the same region using statistical values. The predicted recycling cost was estimated based on assuming segregated collection by the municipalities of all PSW in municipal solid waste. Then the resulting unit cost of recycling was found to be US$0.25 kg-1 of plastic waste. In addition, the recycling costs were also evaluated including the revenue from the sales of recycled plastic granular. According to the evaluated total cost of plastic recycling, it can be concluded that mechanical recycling of plastics can only be an economical option if the recovery of plastics is improved. © The Author(s) 2019 Daha fazlası Daha az

Prediction of sulfur dioxide daily levels in the City of Zonguldak using an adaptive neuro-fuzzy based method

Yıldırım, Yılmaz | Bayramoğlu, Mahmut | Hasıloğlu, Samet

Article | 2003 | Fresenius Environmental Bulletin12 ( 10 ) , pp.1173 - 1179

Air pollution continues to be a major problem in many countries. Mathematical models are useful in relating emissions to air quality under a variety of meteorological conditions and source emission concentrations over an urban area. Meanwhile, the forecasting capability of sophisticated models is limited to very large and complex terrains. In this study, an adaptive neuro-fuzzy logic method has been developed to estimate the impact of meteorological factors on SO2 pollution levels. The model satisfactorily forecasts the trends of SO2 concentration levels with a performance between 78-90%.

The effect of BOD5 and flow-rate of activated sludge systems on investment and energy costs

Altın, Ahmet | Altın, Süreyya | Elevli, Birol | Değirmenci, Mustafa | Özdemir, Alikemal


In this study of wastewater treatment, the effect of flow-rate, BOD5 and other design parameters (MLSS, mean cell-residence time, etc.) on aeration tank dimensions, investment amount and energy cost has been investigated. The relations among these parameters are represented with mathematical equations, which could be useful in new plant design and in the estimation of investment and energy costs.

Transport of Lead (Pb2+) Ions through silty-clayey soils under acidic conditions

Genç, Ayten | Ulupınar, Elif

Article | 2010 | Transport in Porous Media84 ( 3 ) , pp.699 - 709

This study aimed to identify effects of pH on the transport of Pb2+ ions through a saturated silty-clayey soil layer by using advection-dispersion equation (ADE). The predictive accuracy of the solution of ADE depends on the proper determination of the retardation by adsorption and, therefore, the adsorption mechanism of lead onto silty-clayey soil was investigated first by performing batch equilibrium experiments. These results showed that the sorption mechanism of lead onto silty-clayey soil depended on pH and could be best described by the Langmuir isotherm. Based on the results of the sequential experiments, it was also conclude . . .d that the pH dependent charges in silty-clayey soil were mainly associated with the surfaces of carbonates and the specific adsorption of lead ions. The numerical solutions of the combined form of ADE with the Langmuir isotherm indicated that the migration profiles of lead in silty-clayey soil were a strong function of the parameters of the Langmuir isotherm rather than the infiltration velocity. © 2010 Springer Science+Business Media B.V Daha fazlası Daha az

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