Title: Effects of pretreatment methods on solubilization of beet-pulp and bio-hydrogen production yield
Authors: Leyla Ozkan, Tuba H. Erguder, Goksel N. Demirer
Abstract:SSugar processing wastewater and beet-pulp are two major waste streams of sugar-beet processing plants. Contrary to wastewater, beet-pulp is generally used as animal feed in cattle-raising industry. However, it can serve as a substrate for bio-hydrogen production which corresponds to a higher valorization of beet-pulp. Moreover, pretreatment of lignocellulosic materials like beet-pulp is needed in order to improve overall energy efficiency and enable economic feasibility of bio-hydrogen production. Therefore, the effect pretreatment methods (alkaline, thermal, microwave, thermal-alkaline and microwavealkaline) on bio-hydrogen production from sugar beet-pulp through dark fermentation were investigated in this study. Reactors pretreated with alkaline, microwave-alkaline and thermal-alkaline methods yielded significant solubilization of beet-pulp compared to others. Therefore, in the second phase of the study, they were used to pretreat the beetpulp which was then subjected to dark fermentation for bio-hydrogen production. Maximum bio-hydrogen production yield of 115.6 mL H2/g COD was observed in reactor which contained alkaline pretreated beet-pulp.

WATER ENVIRONMENT RESARCH, Volume 83, Number 3, 247-255

Title: Anaerobic-Fed and Sequencing-Batch Treatment of Sugar-Beet Processing Wastes: A Comparative Study
Authors: Emrah Alkaya, Göksel N. Demirer
Abstract:The aim of this study was to compare a batch-fed continuously mixed anaerobic reactor (FCMR) with an anaerobic sequencing batch reactor (ASBR), in terms of waste stabilization and methane production treating sugar-beet processing wastewater and beetpulp simultaneously. A reactor was operated as FCMR, which then was operated as an ASBR by changing operational conditions after the steadystate was reached. Although the hydraulic retention time value of the ASBR configuration was lower (8 days) than that of the FCMR (15 days) and the corresponding organic loading rate (OLR) was higher (0.71 to 1.33 g COD/L.d), increased biomass retention enabled a significant increase in biomethanation for the ASBR configuration. So, methane production yield of 255 ± 11 mL/g COD-added was increased to 337 ± 15 mL/g COD-added (32.2% increase in methane yield) when the configuration was changed from FCMR to ASBR. The experimental results indicated that the ASBR configuration, which was applied to sugarbeet processing wastes for the first time, was superior to the FCMR configuration.

ENVIRONMENTAL TECHNOLOGY Vol. 32, No. 7, 2011, 783–794

Title: Removal and recovery of nutrients as struvite from anaerobic digestion residues of poultry manure
Authors: Y.D. Yilmazel and G.N. Demirer
Abstract:The removal and the recovery of nutrients, namely nitrogen (N) and phosphorus (P) from anaerobically digested and solid–liquid separated manure effluents via struvite precipitation were investigated. Both the liquid and the solid phases of the poultry manure digester effluent were subjected to struvite precipitation experiments. The Mg:N:P molar ratio of 1:1:1 in the liquid phase resulted in an average NH4-N removal efficiency of 86.4%, which increased to 97.4% by adjusting the Mg:N:P ratio to 1.5:1:1. The acidic phosphorus-dissolution process was applied to the solid phase of the effluent to obtain a phosphorus-enriched solution. Nutrient recovery experiments with NaOH as the buffering reagent were conducted with and without addition of external chemicals (Mg and P sources) to evaluate the influence of the Mg:N:P molar ratio, the Mg:P molar ratio and pH. All the experiments depicted complete PO4-P (99.6–100.0%) and partial NH4-N (3.3–65.6%) recoveries from the phosphorus-enriched solution.


Title: Anaerobik olarak çürütülmüş arıtma çamurlarından strüvit çöktürmesiyle nütrient geri kazanımı
Authors: Ayla UYSAL, Y. Dilşad YILMAZEL, Göksel N. DEMİRER
Abstract:Bu çalışmada, kentsel nitelikli anaerobik çürütülmüş çamurdan strüvit formunda nütrient geri ka-zanımı potansiyeli araştırılmıştır. Çürütülmüş çamurun katı fazından fosforun geri kazanımı için, katı faza fosfor çözündürme prosesinin uygulanması gerekmektedir. Çalışmada, çürütülmüş çamur katı fazına asidik koşullarda fosfor çözündürme prosesi uygulanması ile mevcut fosfor ortofosfata dönüştürülmüştür. Asidik koşullarda çözündürme prosesi ile oldukça yüksek nütrient içeriğine sahip (1085±4.95 mg/L NH3-N ve 840±21.21 mg/L PO4-P) fosforca zengin sıvı fazı elde edilmiştir. Asidik çözündürme prosesinin uygulanması ile katı fazdaki toplam fosforun yaklaşık %84’ü çözündürül-müştür. Fosfor çözündürme prosesinin strüvit çöktürmesi için başlangıç adımı olarak kullanılabile-ceği görülmüştür. Strüvit çöktürmesi testlerinde, Mg:N:P ve Mg:P molar oranlarının etkisi ayrı ayrı incelenmiştir. pH 8.5’da, Mg:N:P molar oranının 2:1:1.3 olduğu durumda PO4-P ve NH3-N gide-rim verimleri %99.84 ve 40.19 olarak elde edilmiştir. Bu durumda, strüvit çöktürmesi ile PO4-P’nin büyük bir kısmının NH4-N’nin ise belirli bir kısmının geri kazanımı gerçekleştirilmiştir. Asidik ko-şullarda çözündürme uygulaması sonucu fosforun yanı sıra serbest kalan metal iyonları, strüvit çöktürmesi sonucunda metal fosfatlar olarak çöktürülmüştür. Çalışmada, asidik çözündürme sonra-sı sıvı fazda mevcut bulunan Ca, Al, Fe ve Zn metallerinin yüksek konsantrasyonlarından dolayı, giderilen PO4-P’nin tamamı magnezyum amonyum fosfat olarak strüvit formunda giderilmemiştir. Bu durum strüvit katı fazında yapılan XRD analizi ile desteklenmiştir. XRD analizi sonucu, strüvite ek olarak diğer metal bileşiklerinin de mevcut olduğu görülmüştür.


Title: Recovery of Nutrients from Anaerobic Co-digestion Effluents of Poultry Manure and Sewage Sludge as Struvite
Authors: Y. Dilsad Yilmazel, Ayla Uysal, Goksel N. Demirer
Abstract:Nutrient recovery from effluents of an anaerobic digestor co-digesting poultry manure and sewage sludge via struvite precipitation was successfully demonstrated. A set of mesophilic anaerobic batch reactors were operated using poultry manure and sewage sludge as the substrates. The struvite precipitation experiments were conducted with the liquid phase of these reactors. The total COD removals and the methane yields of the reactors ranged between 43–63 % and 146–228 mLCH4/gCOD added, respectively. The effects of pH, seeding and calcium on struvite precipitation process were investigated. The results revealed that high NH4-N recovery efficiencies (77 - 84 %) were possible by the adjustment of struvite stoichiometry (Mg:N:P of 1:1:1) in the reactors effluents. It was also observed that the final pH adjustment did not result in any significant increase in the removal of NH4-N at the pH levels tested (8.0, 8.5 and 9.0). Moreover, the seeding material addition was investigated to improve the performance of struvite formation by providing the adequate surface for reaction. The impact of seeding on residual NH4-N concentration was negligible, however its impact on residual PO4-P concentration was significant and highly dependant on the composition of the wastewater used. Calcium concentration in the effluents was much higher than other metal concentrations and its effect on struvite precipitation was investigated through varying the Mg:Ca molar concentration ratio. The results indicated that Ca has inhibitory effects of the struvite reaction. The presence of Ca led to formation of calcite and amorphous calcium phosphates that were detectable through XRD. The results depicted that the addition of Mg ion above the molar concentration of PO4-P together with Ca ion helped to remove most of the phosphorus even in low phosphorus wastewaters.


Title: Phosphorus Recovery Potential in Anaerobic Digestion Residues
Authors: Y.D. YilmazeL, C. Morgenschweis, G. Mutlu, D. Antakyali, H. Steinmetz, G.N. Demirer
Abstract:This study investigated the phosphorus recovery potential of the anaerobic digestion residues of four different wastes, namely, poultry manure, mixture of swine and cattle manure and energy plants, mixture of poultry manure and maize silage, and sewage sludge. A phosphorus balance was conducted over the process. The calculations depicted that 80-99 % of the phosphorus remain in the solid phase of the digester samples. To increase the efficiency of the phosphorus recovery, P-dissolution process was applied to both the liquid and the solid phase samples with a phosphorus release rate of 76-100%. Several experiments were conducted under different conditions by P-dissolved solutions. The results depicted that the adjustable operational parameters of struvite precipitation process (P:Mg molar ratio, pH) affect the type of the precipitating mineral but not the recovery efficiency. Overall mass balance depicted that the rate limiting step in the process is the P-dissolution i.e. the release of the bound phosphorus into the aqueous phase. This study depicted that 77 – 98% of the phosphorus present in anaerobic digestion residues can be recovered via application of a novel P-dissolution process prior to struvite precipitation.

Journal of Environmental Management 92 (2011) 1577-1583

Title: Allocation of supplementary aeration stations in the Chicago waterway system for dissolved oxygen improvement
Authors: Emre Alp, Charles S. Melching
Abstract:The Chicago Waterway System (CWS), used mainly for commercial and recreational navigation and for urban drainage, is a 122.8 km branching network of navigable waterways controlled by hydraulic structures. The CWS receives pollutant loads from 3 of the largest wastewater treatment plants in the world, nearly 240 gravity Combined Sewer Overflows (CSO), 3 CSO pumping stations, direct diversions from Lake Michigan, and eleven tributary streams or drainage areas. Even though treatment plant effluent concentrations meet the applicable standards and most reaches of the CWS meet the applicable water quality standards, Dissolved Oxygen (DO) standards are not met in the CWS during some periods. A Use Attainability Analysis was initiated to evaluate what water quality standards can be achieved in the CWS. The UAA team identified several DO improvement alternatives including new supplementary aeration stations. Because of the dynamic nature of the CWS, the DUFLOW model that is capable of simulating hydraulics and water quality processes under unsteady-flow conditions was used to evaluate the effectiveness of new supplementary aeration stations. This paper details the use of the DUFLOW model to size and locate supplementary aeration stations. In order to determine the size and location of supplemental aeration stations, 90% compliance with a 5 mg/l DO standard was used as a planning target. The simulations showed that a total of four new supplementary aeration stations with oxygen supply capacities ranging from 30 to 80 g/s would be sufficient to meet the proposed target DO concentration for the North Branch and South Branch of the Chicago River. There are several aeration technologies, two of which are already being used in the CWS, available and the UAA team determined that the total capital costs of the alternatives range from $35.5 to $89.9 million with annual operations and maintenance costs ranging from $554,000 to $2.14 million. Supplemental aeration stations have been shown to be a potentially effective means to improve DO concentrations in the CWS and will be included in developing an integrated strategy for improving water quality in the CWS.


Title: Hazardous waste management in Turkey: current legislative requirements and future challenges
Authors: Cisem Yigit, Gulnur Maden, Nur Disa, Ozge Yılmaz, Abdullah Ogutverici, Emre Alp, Kahraman Unlu,Celal F. Gokçay, Filiz B. Dilek, Ozgur Dogan, Tanju Karanfil, Ulku Yetis
Abstract:Turkey being a candidate country to European Union (EU) is in need of achieving approximation with EU Environmental Acquis including the Hazardous Waste Management. Alignment with the Waste Framework Directive (2006/12/EC) is already accomplished and the Hazardous Waste Directive (HWD) (91/689/EEC) has been almost fully transposed into National Legislation. Yet, there are still some discrepancies regarding the provisions needed for the EU’s reporting requirements. This study aims at providing a detailed description of the information requested by reporting requirements in EU Hazardous Waste Legislation related to the implementation of the HWD in Turkey. Firstly, a comparison of the EU and Turkish hazardous waste legislations is done and discrepancies in Turkish Hazardous Waste legislations are identifi ed. Then, the current state of implementation tools of the transposed reporting requirements is evaluated. Finally, a roadmap for the full and precise transposition and implementation of EU’s Hazardous Waste Management Acquis is developed.


Title: Source Apportionment of Ambient Volatile Organic Compounds in Bursa, a Heavily Industrialized City in Turkey
Authors: Mihriban Yilmaz Civan, Öznur Oğuz Kuntasal and Gürdal Tuncel
Abstract:Weekly passive sampling campaigns were carried out over two sample periods to measure volatile organic compounds (VOCs) in Bursa, one of the most heavily industrialized cities in Turkey. The measurements, taken at 40 points in October 2005 and 49 points in April 2006, revealed concentrations of 34 VOCs, including aromatics, olefins, paraffin and halogenated compounds; with benzene, toluene, ethylbenzene, and o, m, and p-xylene polymers (BTEX) being the most abundant compounds detected at all sample points. Toluene was the most abundant VOC found at all sites, with a median concentration ranging from 0.99 μg/m−3 in background samples to 35.98 μg/m−3 at industrial sites, followed by m- and p-xylene and ethylbenzene. High toluene-to-benzene (T/B) ratios (9.6) were observed at industrial sites, whereas the T/B ratios measured in urban areas and at roadside locations were comparable and were higher than in other countries. A principle component analysis (PCA) using a receptor-oriented source apportionment model was applied to the VOC data and extracted four major sources for both the October and April sampling periods. Principle factors accounted for 85% and 74% of the variance in VOC data for the October and April sample periods, respectively. The identified sources of VOCs in Bursa included: 1) vehicular exhaust (gasoline and diesel engine vehicles), 2) industrial emissions, and 3) evaporative emissions. The explained factors indicated that the urban air in Bursa was influenced by both traffic and industrial sources, each of which displayed different levels.


Title: Assessment of temporal variation and sources of PCBs in the sediments ofMediterranean Sea, Mersin Bay, Turkey
Authors: Kadir Gedik, Ipek Imamoğlu
Abstract:Information on temporal distribution of polychlorinated biphenyls (PCBs) in the coastal sediments of Mediterranean Sea, Mersin was compiled using data published between 1980 and 2009, and the present study. The first congener specific PCB results from the region yield concentration levels of R41PCBs in sediments ranging from 0.61 to 1.04 ng g 1. Sediment profiles show penta-, hexa- and hepta-chlorobiphenyls, specifically, #149 and 153 as the most abundant congeners in all samples. Comparison of total PCB concentrations over time suggests no recent PCB input to the region. Using congener specific PCB data for the region, identity and contribution of PCB sources were also predicted using a chemical mass balance -based (CMB) receptor model. The CMB model identified Aroclor 1260 to be the major PCB source in coastal sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.

ÇEVRE BİLİM VE TEKNOLOJİ Cilt 3 Sayı 3, 169-186

Title: Genetik Algoritma Yardımıyla Model Kalibrasyonu: Aşağı Seyhan Nehri Örneği
Authors: Recep Kaya Göktaş ve Ayşegül Aksoy
Abstract:Bu çalışmada, optimizasyon bazlı model kalibrasyonunun ve verifikasyonunun verimi Aşağı Seyhan Nehri örneği ile çalışılmıştır. Optimizasyon için genetik algoritma (GA) kullanılmıştır. Daha önce yapılmış olan ve deneme-yanılma yöntemiyle kalibrasyonu gerçekleştirilen bir su kalitesi modellemesi çalışması göz önünde bulundurulmuştur. Benzer sistem için GA kullanılarak model kalibrasyonu ve verifikasyonu gerçekleştirilmiştir. Her iki kalibrasyon yöntemiyle kalibre edilen modelle elde edilen su kalitesi değişkenleri konsantrasyonlarındaki değişimler nehir boyunca karşılaştırılmıştır. Sonuçlar GA ile model kalibrasyon ve verifikasyonunun geleneksel deneme-yanılma yöntemine göre daha az zahmetli ve nesnel olarak gerçekleştirilebileceğine işaret etmiştir. Ancak, başarılı sonuçların elde edilmesi veri kalitesine ve gözlem istasyonlarının yerlerine de bağlıdır.


Title: Change in optimal pump-and-treat remediation design and cost for different correlation lengths of spatially variable hydraulic conductivity field
Authors: G. Güngör-Demirci, A. Aksoy
Abstract:In this study, variations in optimal pump-and-treat (P&T) remediation designs and costs for a contaminated and mass-transfer-limited aquifer are investigated for different hydraulic conductivity (K) heterogeneity conditions with focus on the influence of the correlation length (ë) of spatially variable K values. Several heterogeneous K fields with diverse ë values and variances (ó2) are considered. The impact of ë on optimal remediation design selection is analysed considering different relative locations of low and high K regions. Furthermore, optimal designs obtained for different initial contaminant plume configurations are evaluated. Optimal designs are determined using a simulation–optimization approach. Results show that the locations of low and high K zones within an aquifer, and their respective areas defined through ë, affect remediation design and cleanup cost noticeably. It is observed that in addition to typical geostatistical parameters (ë and ó2), better determination of both the spatial distribution of low and high K regions and the initial contaminant mass is critical for better P&T design.


Title: Evaluation of pollution levels at an abandoned coal mine site in Turkey with the aid of GIS
Authors: Firdes Yenilmez, Nazan Kuter, Mustafa Kemal Emil, Aysegul Aksoy
Abstract:Determination of the level of pollution at contaminated sites can be costly due to the number of samples required to identify the areas with higher contaminant concentrations. Yet, if pollution transport pathways can be found, then contamination level can be detected with fewer samples. In this case study, pollution levels at an abandoned coal mine site at Ovacik–Yaprakli (Cankiri, Turkey) are evaluated with respect to topography and surface runoff pathways derived using Geographical Information System (GIS) tools. First, surface runoff pathways are identified using ArcGIS 9.3. Then, the concentrations of trace elements (Mn, Cr, V, Cu, Ni, Zn, Ba, and Sr), pH, Fe and S contents in soil samples taken at random locations around the mine area are determined in a laboratory. In addition, pH and electrical conductivity (EC) are measured in flowing waters in-situ at different locations using pH and EC probes. The spatial distribution of pollutant concentrations is evaluatedwith respect to the surface runoff pathways and locations of potential contamination sources (i.e. open pit, coal storage and dump sites). Finally, the contamination level in the study area is assessed based on the limit values stated in the Soil Pollution Control Regulation of Turkey (SPCR). Results indicate that the site is contaminated with Cr, Ni, and Cu. In general, pollutant concentrations are higher close to the contamination sources and along the surface runoff pathways determined by the ArcGIS. Results indicate that GIS can aid in locating the areas that are more likely to have high pollutant concentrations. This would in return prevent overlooking highly contaminated spots which may be located far away from contamination sources. Moreover, these areas can be determined using a smaller number of samples which would decrease the sampling costs.

RISK ANALYSIS, Vol. 31, No. 4, 2011

Title: Challenges in Development and Implementation of Health-Risk-Based Soil Quality Guidelines: Turkey’s Experience
Authors: Elçin Kentel, Ayşegül Aksoy, Beril Büyüker, Filiz Dilek, Serkan Girgin, Meltem H. İpek, Şener Polat, Ülkü Yetiş ve Kahraman Ünlü
Abstract:Management of contaminated sites is a critical environmental issue around the world due to the human health risk involved for many sites and scarcity of funding. Moreover, clean-up costs of all contaminated sites to their background levels with existing engineering technologies may be financially infeasible and demand extended periods of operation time. Given these constraints, to achieve optimal utilization of available funds and prioritization of contaminated sites that need immediate attention, health-risk-based soil quality guidelines should be preferred over the traditional soil quality standards. For these reasons, traditional soil quality standards are being replaced by health-risk-based ones in many countries and in Turkey as well. The need for health-risk-based guidelines is clear, but developing these guidelines and implementation of them in contaminated site management is not a straightforward process. The goal of this study is to highlight the problems that are encountered at various stages of the development process of risk-based soil quality guidelines for Turkey and how they are dealt with. Utilization of different definitions and methodologies at different countries, existence of inconsistent risk assessment tools, difficulties in accessing relevant documents and reports, and lack of specific data required for Turkey are among these problems. We believe that Turkey’s experience may help other countries that are planning to develop health-risk-based guidelines achieve their goals in a more efficient manner.

ENVIRON EARTH SCI (2011) 63:1277–1288

Title: Variation in time-to-compliance for pump-and-treat remediation of mass transfer-limited aquifers with hydraulic conductivity heterogeneity
Authors: Gamze Güngör-Demirci, Aysegül Aksoy
Abstract:In this study, the impact of correlation length (k) of hydraulic conductivity (K) heterogeneity on pumpand- treat (P&T) remediation period (time-to-compliance) for a mass transfer-limited aquifer is evaluated. Additionally, impacts of variance (r2), different distributions of high and low K zones and different initial contaminant masses are explored. Two different P&T policies including different number of wells pumping at different rates are employed for the investigation. Simulation–optimization approach in which a genetic algorithm (GA) is linked with a groundwater flow and contaminant transport model is used. Results show that K heterogeneity, in terms of kln K, r2 ln K and respective locations of low and high K zones, significantly impacts the time-to-compliance. Contaminant presence at low K zones can increase the time required to clean up the aquifer. Lower variation is observed in timeto- compliance for the remediation design utilizing higher number of wells pumping at slower rates compared to the design with a single well pumping at a higher rate. Higher number of wells increases the robustness of P&T remediation system when aquifer is heterogeneous in K.


Title: Water quality trend analysis in Eymir Lake, Ankara
Authors: Firdes Yenilmez, Fatih Keskin, Aysegul Aksoy
Abstract:In this study, trends in selected water quality parameters in Eymir Lake over a period of 10 years are analyzed using the Mann–Kendall test. Analyzed water quality parameters are dissolved oxygen (DO), total phosphorus (TP), total suspended solids (TSS), and secchi depth (SD). In addition, trends in the yearly averages of precipitation, lake volume, and ambient temperature are examined. According to Mann–Kendall test results, precipitation, volume and ambient temperature values exhibit decreasing trends in 1998–2008. DO and TSS exhibit increasing trends while TP and SD have decreasing trends in Eymir Lake. The change in the volume of the lake has a significant impact on the trends of DO, TSS, and SD. These results indicate that, besides eutrophic conditions, water balance and drought conditions significantly impact the water quality of Eymir Lake.


Title: Current practices in hazardous waste management in Turkey
Authors: Ozge Yilmaz, Betul Dogru, Ulku Yetis
Abstract:As a consequence of restrictive national and international regulations; in recent years, efforts for a better management of hazardous wastes in Turkey have increased considerably. In this article, an overview of the current hazardous waste management practices in Turkey is provided. Initial efforts that have started with ratifi cation of Basel Convention in 1994 are followed by substantial progress owing to alignment with the European Union’s wa ste management acquis in early 2000’s. Overview of the legislative framework indicates that currently, the rules laid down in legal documents are suffi cient to establish an effective hazardous waste management system. However, the implementation and enforcement of the legislation is not complete yet as the implementation requires the considerable improvement of the current infrastructure. The quality of hazardous waste generation data, which is essential for proper design of hazardous waste management system, in Turkey is still of concern therefore, needs further attention. In terms of operational aspects, there are 138 recovery facilities licensed for hazardous waste, four licensed hazardous waste incineration and three licensed hazardous waste disposal facilities throughout Turkey. Due to the fact that established capacities of these facilities are below total hazardous waste generation amounts, new facilities are being planned to be built.

Environ Sci Pollut Res (2011) 18:968–977

Title: A preliminary investigation of the environmental impact of a thermal power plant in relation to PCB contamination
Authors: Kadir Gedik & Ipek Imamoglu
Abstract:Purpose The most significant application of polychlorinated biphenyls (PCBs) is in transformers and capacitors. Therefore, power plants are important suspected sources for entry of PCBs into the environment. In this context, the levels and distribution of PCBs in sediment, soil, ash, and sludge samples were investigated around Seyitömer thermal power plant, Kütahya, Turkey. Moreover, identity and contribution of PCB mixtures were predicted using the chemical mass balance (CMB) receptor model. Methods United States Environmental Protection Agency methods were applied during sample preparation, extraction (3540C), cleanup (3660B, 3665A, 3630C), and analysis (8082A). Results ΣPCB concentrations in the region ranged from not detected to 385 ng/g dry weight, with relatively higher contamination in sediments in comparison to soil, sludge, and ash samples collected from around the power plant. Congener profiles of the sediment and soil samples show penta-, hexa-, and hepta-chlorobiphenyls as the major homolog groups. The results from the CMB model indicate that PCB contamination is largely due to Clophen A60/A40 and Aroclor 1254/1254(late)/1260 release into the sediment and sludge samples around the thermal power plant. Conclusions Since there are no other sources of PCBs in the region and the identity of PCB sources estimated by the CMB model mirrors PCB mixtures contained in transformers formerly used in the plant, the environmental contamination observed especially in sediments is attributed to the power plant. Release of PCBs over time, as indicated by the significant concentrations observed even in surface samples, emphasizes the importance of the need for better environmental management.

Talanta 83 (2011) 823–831

Title: An approach to measure trace elements in particles collected on fiber filters using EDXRF
Authors: Fatma Öztürk, Abdullah Zararsız, Rıdvan Kırmaz, Gürdal Tuncel
Abstract:A method developed for analyzes of large number of aerosol samples using Energy Dispersive X-Ray Fluorescence (EDXRF) and its performance were discussed in this manuscript. Atmospheric aerosol samples evaluated in this study were collected on cellulose fiber (Whatman-41) filters, employing a Hi-Vol sampler, at a monitoring station located on the Mediterranean coast of Turkey, between 1993 and 2001. Approximately 1700 samples were collected in this period. Six-hundred of these samples were analyzed by instrumental neutron activation (INAA), and the rest were archived. EDXRF was selected as an analytical technique to analyze 1700 aerosol samples because of its speed and non-destructive nature. However, analysis of aerosol samples collected on fiber filters with a surface technique such as EDXRF was a challenge. Penetration depth calculation performed in this study revealed that EDXRF can obtain information from top 150 µm of our fiber filter material. Calibration of the instrument with currently available thin film standards caused unsatisfactory results since the actual penetration depth of particles into fiber filters were much deeper than 150 µm. A method was developed in this manuscript to analyze fiber filter samples quickly with XRF. Two hundred samples that were analyzed by INAA were divided into two equal batches. One of these batches was used to calibrate the XRF and the second batch was used for verification. The results showed that developed method can be reliably used for routine analysis of fiber samples loaded with ambient aerosol.