Publications2013

CHEMICAL ENGINEERING JOURNNAL 217 (2013) 273–280

Title: An ozone assisted process for treatment of EDC’s in biological sludge
Authors: M. Muz, M.S. Ak, O.T. Komesli, C.F. Gökçay
Abstract:A novel aerobic sludge digestion process to stabilize and decrease the amount of excess sludge produced during biological treatment and removal of EDCs sorbed onto sludge during this process is discussed here. Waste activated sludge samples from two different wastewater treatment plants were ozonated for different periods in Erlenmeyer flasks once a day on each of four consecutive days. Flasks were continuously aerated between ozone applications by shaking on an orbital shaker. The residual EDC concentrations in sludge samples were analyzed at the end of digestion periods. An MLVSS reduction of up to 95% was achieved with an ozone dose of only 1.05 g O3/kg MLSS in this process on the fourth day. During this process destruction of some selected endocrine disrupting compounds, namely diltiazem, carbamazepine, butyl benzyl phthalate, acetaminophen and two natural hormones, estrone and progesterone, which tend to accumulates in sludge, are studied. Over 99% removal of these contaminants were achieved at the end of the fourth day. The analyses were conducted by using LC (ESI) MS/MS after solid phase extraction (SPE). By this process it became possible to save on contact time as well as achieving a bio-solids digestion far exceeding the standard aerobic process and concomitant removal of micropollutants at the expense of minimum ozone dose. The developed process is deemed superior over side-stream ozonation of activated sludge, in that it does not cause reduction in active biomass in the aeration tank.

WATER AIR SOIL POLLUTION (2013) 224

Title: Source Apportionment of Personal Exposure to Fine Particulate Matter and Volatile Organic Compounds using Positive Matrix Factorization
Authors: Hakan Pekey, Beyhan Pekey, Demet Arslanbaş, Zehra Bulut Bozkurt, Güray Doğan, Gürdal Tuncel
Abstract:The objective of this study was to identify potential sources of personal exposure to fine particulate matter (PM2.5), volatile organic compounds (VOCs), NO2, SO2, and O3 in an urban and industrial area of Turkey between May 2006 and January 2007. Personal exposures were determined once per person in 28 adults over a 24-h period. Energy dispersive Xray fluorescence and a wavelength dispersive X-ray fluorescence spectrometry were used to measure 15 elements in PM2.5, including Al, As, Ca, Cr, Cu, Fe, K, Mn, Ni, Pb, S, Si, Ti, V, and Zn. The VOCs benzene, toluene, m/p-xylene, o-xylene, ethylbenzene, styrene, cyclohexane, 1,2,3-trimethylbenzene, 1,2,4- trimethylbenzene, 1,3,5-trimethylbenzene, hexane, heptane, nonane, octane, decane, undecane, and dodecane were measured by thermal desorption and gas chromatography/flame ionization. Application of positive matrix factorization to the data obtained suggests that motor vehicles, indoor sources, and industry represent the main emission sources of the investigated chemical species. Six major sources smoking (9 %), industry (15 %), gasoline exhaust (21 %), indoor sources (17 %), diesel exhaust (19 %), and crustal (19 %) were identified.

JOURNAL OF ENVIRONMENTAL MANAGEMENT 116 (2013) 145-155

Title: Modeling evaluation of integrated strategies to meet proposed dissolved oxygen standards for the Chicago waterway system
Authors: Charles S. Melching, Yaping Ao, Emre Alp
Abstract:The Chicago Waterway System (CWS) is a 113.8 km branching network of navigable waterways controlled by hydraulic structures in which the majority of flow is treated sewage effluent and there are periods of substantial combined sewer overflow. The Illinois Pollution Control Board (IPCB) designated the majority of the CWS as Secondary Contact and Indigenous Aquatic Life Use waters in the 1970s and made small alterations to these designations in 1988. Between 1988 and 2002 substantial improvements in the pollution control and water-quality management facilities were made in the Chicago area. The results of a Use Attainability Analysis led the Illinois Environmental Protection Agency (IEPA) to propose the division of the CWS into two new aquatic life use classes with appropriate dissolved oxygen (DO) standards. To aid the IPCB in their deliberations regarding the appropriate water use classifications and DO standards for the CWS, the DUFLOW model that is capable of simulating hydraulics and water-quality processes under unsteady-flow conditions was used to evaluate integrated strategies of water-quality improvement facilities that could meet the proposed DO standards during representative wet (2001) and dry (2003) years. A total of 28 new supplementary aeration stations with a maximum DO load of 80 or 100 g/s and aerated flow transfers at three locations in the CWS would be needed to achieve the IEPA proposed DO standards 100% of the time for both years. A much simpler and less costly (zone tenth of the cost) system of facilities would be needed to meet the IEPA proposed DO standards 90% of the time. In theory, the combinations of flow augmentation and new supplemental aeration stations can achieve 100% compliance with the IEPA proposed DO standards, however, 100% compliance will be hard to achieve in practice because ofd(1) difficulties in determining when to turn on the aeration stations and (2) localized heavy loads of pollutants during storms that may yield violations of the DO standards even with an extensive network of supplemental aeration stations. Thus, because absolute DO standards that must be met 100% of the time will be difficult, if not impossible to comply with, DO standards that include aWet Weather Limited Use (WWLU) designation based on rainfall amount triggering CSO events and a maximum duration that the WWLU could be applied should be considered to obtain a healthy ecosystem by applying water-quality improvement features that can be practically operated and maintained. Such a WWLU approach also was evaluated in this paper.

LIMNOLOGICA 43 (2013) 1–9

Title: Comparison of phosphorus reduction alternatives in control of nutrient concentrations in Lake Uluabat (Bursa, Turkey): Partial versus full sediment dredging
Authors: Firdes Yenilmez, Aysegul Aksoy
Abstract:In this study, Water Quality Analysis Simulation Program (WASP) was used to simulate the impacts of various phosphorus (P) load reduction scenarios on nutrient concentrations in Lake Uluabat, a Ramsar site (a wetland of international importance designated under the Ramsar Convention), including sediment dredging options and source reduction. The model was calibrated for various water constituents including orthophosphate (PO4 3-) and nitrate (NO3 -). The calibrated model was used as a management tool to predict the nutrient concentrations and water quality conditions in the lake for different P management alternatives. Results indicated that due to heavy sediment load, sediment dredging may be required to improve the water quality and control eutrophication in short term. However, it was observed that partial sediment dredging combined with other P load reduction alternatives could have similar overall effects compared to full sediment dredging in long term. Therefore, partial sediment dredging could be used as an alternative P control strategy when applied together with other P load control options.

ECOLOGICAL INDICATORS 29 (2013) 6–17

Title: Development of pollution indices for the middle section of the Lower Seyhan Basin (Turkey)
Authors: Mehmet Golge, Firdes Yenilmez, Aysegul Aksoy
Abstract:Pollution indices aggregate concentrations of several water or air quality parameters into a single quantity to indicate the general status of pollution in a region. Several pollution index models are present in literature. However, their application for different cases may require modifications based on implementation goals and available data. In this study, modified pollution indices were used to evaluate the pollution status in the middle section of the Lower Seyhan River Basin by employing a geographical information system (GIS) software (ArcGIS 9.3) for data processing, estimations and evaluations. Air quality index (AQI) and water quality index (WQI) were utilized to evaluate air and water pollution levels, respectively. Moreover, a composite air–water quality index (AWQI) was developed to perform a general assessment about the overall pollution status. The WQI and AQI were calculated for 2004–2010 and 2007–2010, respectively. The AWQI was developed for the period of 2007–2010. Results indicated that for the available data and time frame considered in the study, air and water qualities were in good conditions (low pollution), in general. Yet, precautions could still be taken for improvement. Results also indicated the need for improvement of monitoring network for better assessment of the environmental quality in the whole basin. In general, GIS tools were very helpful in the development of the indices.

JOURNAL of ENVIRONMENTAL SCIENCE and HEALTH, Part A (2013) 48, 800–808

Title: Levels and sources of polychlorinated biphenyls in Ankara creek sediments, Turkey
Authors: NAZAN AKDUMAN ÖZYÜREK, KADIR GEDIK, ESRA ŞILTU and İPEK İMAMOĞLU
Abstract:The spatial distribution, degree of pollution and major sources of polychlorinated biphenyls (PCBs) were evaluated in surficial sediments of Ankara Creek, located in the capital of Turkey and serving as one of the tributaries in the third largest watershed in Turkey. Sediment ?PCB concentrations analyzed on Aroclor and congener basis (seven indicator congeners) range from 5.5 to 777.6 ng g-1 and 3.7 to 743.3 ng g-1 dw as Aroclor and congener based concentrations, respectively. High concentrations of PCBs were observed in the samples located at the downstream sections of the Creek, after discharge from Ankara municipal wastewater treatment plant. Using a chemical mass balance receptor model (CMB), major sources of PCBs affecting the sediments were investigated. The CMB model identified Aroclor 1254 and 1260 to be the major PCB sources affecting sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.

WATER RESEARCH 47 (2013) 428-438

Title: Can sludge dewatering reactivate microorganisms in mesophilically digested anaerobic sludge? Case of belt filter versus centrifuge
Authors: M. Erkan, F.D. Sanin
Abstract:The anaerobic digestion process that successfully reduces the organic content of sludge is one of the most common alternatives to meet pathogen reduction requirements for particular classes of biosolids. However, recently it was reported that,much higher densities of indicator bacteria were measured in dewatered cake samples compared to samples collected after anaerobic digestion. Additionally, this increase was commonly observed after centrifugation but not after belt filter dewatering. Several hypotheses were tested to explain this occurrence; however, much of the attention was given to the reactivation of the indicator bacteria which might enter a viable but non-culturable state (VBNC) during digestion. The objective of this research is to examine sludge samples from 5 different fullscale treatment plants in order to observe the effect of dewatering processes on the reactivation potential of indicator bacteria. The bacterial enumerations were performed by both Standard Culturing Methods (SCM) and quantitative polymerase chain (qPCR) on samples collected after digestion and dewatering. Results obtained by SCM indicated that in two investigated treatment plants operating belt filter dewatering, an average 0.6 log decrease was observed after the dewatering process. However, 0.7e1.4 log increases were observed immediately after centrifuge dewatering for the other three treatment plants. On the other hand, qPCR results gave 0.1e1.9 log higher numbers compared to SCM. Comparative evaluation of results obtained by two analytical methods for five treatment plants indicates that the differences observed might be originating from both reactivation of VBNC bacteria and amplification of DNA from dead cells found in the sludge.

INTERNATIONAL BIODETERIORATION & BIODEGRADATION 83 (2013) 41-47

Title: Anaerobic mesophilic digestion of waste activated sludge in the presence of 2,3’,4,4’,5-pentachlorobiphenyl
Authors: Devrim Kaya, Ipek Imamoglu, F. Dilek Sanin
Abstract:The aim of this study was to investigate the anaerobic digestion of waste activated sludge in the presence of a model PCB congener, 2,3’,4,4’,5-pentachlorobiphenyl (PCB-118), and transformer oil (TO), and thereby PCB dechlorination under mesophilic digestion conditions. Two PCB-118 concentrations (1 and 20 mg/L) and one TO concentration (1.52 g/L) were studied. Beside the PCB concentrations, pH, ORP, TS, VS, VSS, TSS, tCOD, and sCOD were monitored throughout the reactor operations (159-day). Methane productions of PCB reactors were considerably lower than that of control reactor (R-C), indicating the negative effect of PCB on methane production. The highest COD removal, 56%, was observed in R-C, followed by 1 and 20 mg/L PCB-118 reactors (46.7% and 40.6% reduction), respectively. VS reductions were between 36 and 52%, with the lower removal in the higher PCB-118 containing reactor. About 12 and 22% PCB-118 removals were attained proportional to their initial concentrations, 1 and 20 mg/L, respectively.

CLEAN SOIL AIR WATER,41,4, 2013, 396-402

Title: Disintegration of Sludge by Sonication and Improvement of Methane Production Rates in Batch Anaerobic Digesters
Authors: Gözde T. Zorba and F. Dilek Sanin
Abstract:Sludge pretreatment prior to anaerobic digestion has been found to reduce sludge production in wastewater treatment. Sludge disintegration using physical, chemical, biological, or mechanical methods can increase biogas production and reduce sludge quantities. Ultrasonication is one of the most effective means of mechanical disintegration. This study aims to investigate ultrasonication as a means for solubilizing waste activated sludge (WAS) to enhance its digestability. Sonication was applied by the use of two different probes providing different powers and energies into the sludge after which the soluble chemical oxygen demand (sCOD) increases were measured. The samples were then digested anaerobically in 250mL serum bottles for about 50 days. Along with the biogas measurements, the rate of methane production is calculated to be able to quantify the effect of pretreatment and compare the results between different applications. The results showed that with the increase of sonication power and sonication time, sCOD increased. An introduction of higher sonication energy made the sCOD rise sharply, however, this increase was not indefinite; it became gradually lower with the further increase of energy. The results indicated that specific methane production, specific methane yield, and the first order methane generation rate increased with increasing energy input.

JOURNAL of POLYMER ENGINEERING, 33:3, 239-246, 2013

Title: Comparison of chemical fractionation method and H-NMR spectroscopy in measuring the monomer block distribution of algal alginates
Authors: Çiğdem Kivilcimdan Moral, Özdemir Doğan and Faika Dilek Sanin
Abstract:Alginates are composed of ß -D-mannuronic acid (M) and ? -L-guluronic acid (G). In this study, block distributions of alginate samples were measured by a chemical fractionation method and H-NMR spectroscopy, to compare the usefulness of the two methods. Block distribution results obtained from the two methods were found to be statistically different from each other; the chemical fractionation method gave consistently lower estimates for the amount of homopolymeric blocks. The repeatability of the results was also lower in the chemical fractionation method. By contrast, H-NMR spectroscopy was found to be a reproducible and a faster method for determining the distribution of monomeric blocks in alginates.

Energy Sources, Part A, 35:2257–2263, 2013

Title: An Investigation of the Kinetics and Oxidative Thermodegradation Properties of Waste Telephone Pole Samples Treated with Metal Salts
Authors: S. Y. Yorulmaz and A. T. Atimtay
Abstract:In the present study, combustion mechanisms, activation energy, and exponential constants were investigated for natural pine and acid copper chromate impregnated telephone pole. Oxidative ther- modegradation was carried out in air environment at different heating rates by using thermogravimetric analysis. In order to calculate thermal kinetics, the Coats Redfern method was used. There were less flammable products, lower weight losses in the main oxidation region, a decrease in the maximum weight loss temperatures, and more char formation for treated samples as compared to untreated samples. In other words, due to treatment of wood with acid copper chromate, thermal properties of wood changed.

Bull Environ Contam Toxicol (2013) 90:27–33

Title: Real-Time PCR Investigation of the Dynamic Expression of Three ‘‘RNA Processing and Modification’’ Genes of Phanerochaete chrysosporium Exposed to Lead
Authors:Elif Tekin, Bulent Icgen, Gulay Ozcengiz
Abstract:The expression of three ribosome binding proteins namely; polyadenylate-binding protein, splicing factor RNPS1 and ATP-dependent RNA helicase of Phanerochaete chrysosporium exposed to lead were analyzed by real-time PCR.

Journal of Residuals Science & Technology, Vol. 10, No. 3—July 2013

Title:Current Situation and Future Perspectives in Municipal Wastewater Treatment and Sludge Management in Turkey
Authors:G. İNSEL, E. KENDIR, A. AYOL, A. ERDINÇLER, O. ARIKAN, İ. İMAMOĞLU, B. A. ALAGÖZ, E. B. GENÇSOY, F. D. SANIN, N. BÜYÜKKAMACI, Ö. KARATAŞ, G. SAYGILI, G. ŞENER, E. U. ÇOKGÖR and A. FILIBELI
Abstract:Appropriate management of wastewater and sludge requires several systems. One of these systems is the collection of data about generation rates and characteristics of sludge. This paper aims to summarize the work done as a part of a threeyear project requested by the Turkish Ministry of Environment and Urbanization. Efforts involved preparation and evaluation of a detailed questionnaire for currently operated wastewater treatment plants (WWTPs) in Turkey, collection and confirmation of information from visits to large scale plants, calculation of theoretical sludge generation rates from data provided, and its comparison to reported sludge amounts.

Resources, Conservation and Recycling 77 (2013) 89– 96

Title:Greening of production in metal processing industry through process modifications and improved management practices
Authors:Emrah Alkaya, Göksel N. Demirer
Abstract:Although it was indicated through various studies from around the world that resource efficiency can be adapted in metal processing plants, a very limited number of projects could be realized in Turkish metal processing industry so far. In this study it was aimed at investigating process modifications and management practices to increase water and chemical use efficiency thus increasing environmental and economic performance of a metal processing company. As a result of the applications in heat treatment and zinc phosphating processes total water consumption of the company was reduced by 34.1% corresponding to an annual water saving of 18,831 m3. Moreover, total chemical consumption in zinc phosphating as one of the most chemical intensive processes in the company, was decreased by 1401 kg/year (26.1%). Applications in zinc phosphating process led to a significant decrease in the amount of treated wastewater and wastewater treatment sludge which is labelled as hazardous waste according to national legislations. Total wastewater generation was decreased by 3255 m3/year (50.9%) while wastewater treatment sludge was reduced 4656 kg/year (16.9%). Moreover, energy consumption of the company was reduced by 32.647 kW h/year which corresponds to 36% energy saving in water pumping. Implementation cost of the applications were 34,233$ which is calculated to be paid back in 2.3 years. This study is expected to fill a gap in Turkey by demonstrating that environmental performance in metal processing industry could be improved by process modifications and improved management practices resulting in tangible economic gains.

Bull Environ Contam Toxicol (2013) 91:177–183

Title:Multidrug and Heavy Metal-Resistant Raoultella planticola Isolated from Surface Water
Authors:Serkan Koc, Burak Kabatas , Bulent Icgen
Abstract:A surface water isolate of Raoultella sp. having both multidrug- and multimetal-resistant ability was isolated and identified as Raoultella planticola. R. planticola displayed resistance to 15 drugs like ampicillin, amoxicillin/ clavulanic acid, aztreonam, erythromycin, imipenem, oxacillin, pefloxacin, penicillin, piperacillin, piperacillin/ tazobactam, rifampin, sulbactam/cefoperazone, ticarsillin, ticarsillin/clavulanic acid, vancomycin, and to 11 heavy metals like aluminum, barium, copper, iron, lead, lithium, manganese, nickel, silver, strontium, and tin. The multidrug and multi-metal-resistant R. planticola may remain present in the environment for a long time. Due to a possible health risk of these pathogenic bacteria, a need exists for an accurate assessment of their acquired resistance to multiple drugs and metals.

Bull Environ Contam Toxicol (2013) 91:697–703

Title:Surface Water-Borne Multidrug and Heavy Metal-Resistant Staphylococcus Isolates Characterized by 16S rDNA Sequencing
Authors:Fadime Yilmaz, Nazlı Orman, Gamze Serim, Ceren Kochan, Aysun Ergene, Bulent Icgen
Abstract:Four Staphylococcus isolates having both multidrug- and multimetal-resistant ability were isolated from surface water. Further identification of the isolates was obtained through biochemical tests and 16S rDNA gene sequencing. One methicillin-resistant and two methicilin- sensitive isolates were determined as Staphylococcus aureus. The other isolate was identified as Staphylococcus warneri. The antibiotic and heavy metal resistance profiles of the Staphylococcus isolates were determined by using 26 antibiotics and 17 heavy metals. S. aureus isolates displayed resistance to most of the b-lactam antibiotics tested. All Staphylococcus isolates were resistant to heavy metals including silver, lithium, and barium. Due to a possible health risk of these pathogenic bacteria, a need exists for an accurate assessment of their acquired resistance to multiple drugs and metals.

Environmental Science & Policy 31 (2013) 34–43

Title:Hydropower in Turkey: Economical, social and environmental aspects and legal challenges
Authors:Elçin Kentel, Emre Alp
Abstract:Turkey, as a rapidly developing and industrializing country, is in need of reliable, inexpensive, and high quality energy. The main energy sources of Turkey are coal, natural gas and hydropower. However, almost all the natural gas and high quality coal is imported. Thus, hydropower is the main domestic energy source. According to the State Hydraulic Works (SHW), the primary executive state agency responsible for the planning, operation, and management of water resources, Turkey has an economically viable hydroelectric potential of 140,000 GWh/year. Currently, around 35% of this potential is utilized. Increasing the share of hydropower in the energy budget of Turkey will reduce dependency on foreign energy sources. However, development of the unused hydropower potential, especially through run-of-river plants, has caused many problems in the country. Run-of-river plants are small hydropower plants (SHPPs) usually with no storage. Electricity Market Law No. 4628 which came into effect in February 2001 was a major step towards the privatization of the electricity sector. The law enabled planning and construction of SHPPs by the private sector. This created a big market for consulting firms which prepare feasibility reports, construction companies, and companies that own and operate these SHPPs. However, due to inadequate water resources management strategies, rivers are impaired; their natural flows are disturbed to generate electricity without paying necessary attention to components of the ecosystem and the needs and concerns of local residents. Thus, Turkey faces a challenging problem: Maximizing the utilization of hydropower which is the main domestic energy source while maintaining environmentally conscious and sustainable development. This study aims to explain the change in the contribution of hydropower in the energy budget of Turkey with time and current social and environmental problems associated particularly with SHPPs. Issues requiring immediate attention to facilitate sustainable development of hydropower potential are identified.

Waste Management & Research 31(8) 792– 804

Title:Hydropower in Turkey:Nitrogen and phosphorus recovery from anaerobic co-digestion residues of poultry manure and maize silage via struvite precipitation
Authors:Y Dilsad Yilmazel and Goksel N Demirer
Abstract:Anaerobic digestion is commonly used for the stabilization of agricultural and animal wastes. However, owing to the stringent environmental criteria, anaerobic digester effluents need to be further treated to reduce nutrient loads to the receiving water bodies. Struvite precipitation is one of the promising techniques applied for this purpose. Yet, in the majority of cases, struvite precipitation is only applied to the liquid phase of anaerobic digester effluents. This study investigated the recovery of nutrients from both the liquid and the solid phases of the phase-separated effluent of a full-scale biogas plant co-digesting poultry manure and maize silage. Struvite precipitation in the liquid phase led to 72.1% and 95.1% average removal efficiencies of ammonium-nitrogen (NH4-N) and orthophosphate respectively. Changing the external phosphorus source did not make any statistically significant difference in nutrient removal. An acidic phosphorus-dissolution process was applied to the solid phase sample to obtain a phosphorus-enriched solution. More than 90.0% of both NH4-N and PO4-P were recovered from the phosphorus-enriched solution with the amendments of magnesium and phosphorus. In the experiments performed without any addition of external magnesium- and phosphorus-containing chemicals, almost complete (99.6%) PO4-P recovery and partial (14.6%) NH4-N recovery were obtained. The results of this study could contribute to the understanding of nutrient recovery from anaerobic digestion residues of manure and agricultural wastes by struvite precipitation.

Appl Microbiol Biotechnol (2013) 97:7899–7907

Title:The effect of managing nutrients in the performance of anaerobic digesters of municipal wastewater treatment plants
Authors:Sibel Uludag Demirer, Bilgin Taskin, Goksel N. Demirer, Metin Duran
Abstract:Is it possible to create conditions in the anaerobic digesters to control nutrients without changing the performance of a reactor? This study investigates an answer for this question. To this purpose, anaerobic reactors are operated at high concentrations of Mg2+ ion to harvest the nutrient ions (NH4 + and PO4 3-) in the form of struvite, that is, magnesium ammonium phosphate. The effects of this modification on the anaerobic digestion of sewage sludge were investigated in terms of chemical oxygen demand (COD) removal and cumulative CH4 production as well as the changes in the biological diversity. The results showed that approximately 50 % of the nutrients (NH4 + and PO4 3-) were removed regardless of the method adopted for the addition of Mg2+ ion, slug or daily dosing. The numbers of Methanosaeta and Methanosarcina in the samples withdrawn prior to and after the addition of Mg2+ did not show significant difference according to the results obtained from qPCR analyses. The research results showed that the addition of Mg2+ into the anaerobic digesters in municipal wastewater treatment facilities may help to remove the nutrients from the effluent while recovering in their solid forms.

Bioresource Technology 148 (2013) 149–156

Title:The effects of aerobic/anoxic period sequence on aerobic granulation and COD/N treatment efficiency
Authors:Yusuf Çağatay Erşan, Tuba Hande Erguder
Abstract:The effects of period sequence (anoxic–aerobic and aerobic–anoxic) on aerobic granulation from suspended seed sludge, and COD, N removal efficiencies were investigated in two sequencing batch reactors. More stable granules with greater sizes (1.8–3.5 mm) were developed in R1 (anoxic–aerobic sequence). Yet, no significant difference was observed between the reactors in terms of removal efficiencies. Under optimum operational conditions, 92–95% COD, 89–90% TAN and 38–46% total nitrogen removal efficiencies were achieved. The anoxic–aerobic period sequence (R1) resulted in almost complete denitrification during anoxic periods while aerobic–anoxic sequence (R2) led to nitrate accumulation due to limited-carbon source and further granule disintegration. NH3–N concentration of 15–28 mg/L was found to inhibit COD removal up to 30%. This study also revealed the inhibitory sulfide production during anoxic periods. Sulfate concentration of 52.6–70.2 mg/L was found to promote sulfate reduction and sulfide generation (0.24–0.62 mg/L) which, together with free-ammonia, inhibited TAN oxidation by 10–50%.

Chemical Engineering Journal 230 (2013) 499–505

Title:Enhancement of bio-gas production and xenobiotics degradation during anaerobic sludge digestion by ozone treated feed sludge
Authors:M.S. Ak, M. Muz, O.T. Komesli, C.F. Gökçay
Abstract:Elimination of large amounts of sludge produced during biological treatment is a pressing environmental issue both in this country and elsewhere. For example EU Landfill Directive 99/31/EC [41] prohibits landfilling of both liquid and untreated wastes with a target to reduce the current amount of bio-degradable wastes, including sewage sludge, 50% and 65% by the years 2013 and 2020, respectively. Anaerobic digestion has now proven to be the most energy efficient way of destroying and stabilizing waste activated sludge and the methane by-product is a form of fuel. It is demonstrated in this research that anaerobic digestion of waste activated sludge, when coupled with mild ozone treatment (e.g., 1.33 mg O3/g-VSS), practically doubles the volume of biogas produced as compared to conventional digesters, while producing no waste sludge for disposal. Ozone treatment of the feed sludge also affects enhanced removal of endocrine disrupting compounds, EDCs, sorbed onto the sludge.

Geomicrobiology Journal (2013) 30, 381–390

Title:Biochemical and Molecular Characterization of Strontium-resistant Environmental Isolates of Pseudomonas fluorescens and Sphingomonas paucimobilis
Authors:GAMZE OZER, AYSUN ERGENE and BULENT ICGEN
Abstract:Strontium resistancewas investigated in strains isolated fromthe riverKızılırmakwhich has been affected by industrial and agricultural heavy metal pollution from the surrounding facilities and domestic effluents from the city Kırıkkale, Turkey. Strontium-resistant isolates with a minimal inhibitory concentration of 2000 mg L-1 were isolated and identified as Pseudomonas fluorescens and Sphingomonas paucimobilis. Both isolates were shown to be resistant to other heavy metals like aluminum, lithium, barium, nickel and resistance to the antibiotics like aztreonam and pefloxacin. Plasmid DNA analysis, transformation and curing results revealed that the strontium resistance ability of both isolates was chromosome-encoded. Outer membrane and total protein isolation results descriptively showed that not only membrane porins but also other proteins were effective in the strontium resistance in Pseudomonas fluorescens and Sphingomonas paucimobilis.

Bull Environ Contam Toxicol (2013) 91:141–147

Title:Apportionment of PCB Sources Near a Transformer Maintenance and Repair Facility in Ankara, Turkey
Authors:Filiz Karakas, Kadir Gedik, Ipek Imamoglu
Abstract:The concentration and major sources of polychlorinated biphenyls (PCBs) were evaluated in the sediments from a special environmental protection area located near a transformer maintenance and repair facility (TMRF) in Ankara, Turkey. ?PCB concentrations analyzed on Aroclor and congener basis (seven indicator congeners) ranged from 0.1 to 84.2 and 0.1 to 21.7 ng/g dry weight, respectively. Results show that higher total PCB concentrations were localized around one of the drainage channels of the TMRF. Identity and contribution of PCB sources were predicted using a chemical mass balance (CMB) based receptor model. The CMB model typically identified Aroclor 1260, the PCB mixture frequently used in transformers, as the major PCB source confirming the effect of the TMRF on the area. Poor prediction of some sample congener profiles suggest presence of environmental degradation mechanisms such as volatilization and differential solubilization of lower chlorinated congeners from sediments.

Journal of Environmental Management 127 (2013) 237-243

Title:Diversity and community analysis of ammonia oxidizing bacteria in a streambed surrounding an artificial dam
Authors:Robert W. Murdoch, Andria Costello Staniec
Abstract:The degree to which small natural dams affect the native bacterial nitrogen cycling community was explored by molecular methods. The identities and relative abundances of ammonia oxidizing bacteria in the sediment surrounding an artificial dam both at the surface and in the hyporheic zone were characterized. Analyses were performed using tRFLP of the conserved amoA gene using a semi-nested degenerate PCR approach. Additionally, an amoA gene library was constructed to characterize the most dominant sediment genotypes. The results of the tRFLP analyses showed clear differences between the upstream and downstream communities at different depths in the sediment column. Non-metric multidimensional scaling ordination of the tRFLP data set produced a stable one-dimensional solution with significant correlations to oxygen, pH, nitrate, and dissolved organic nitrogen levels. The sample corresponding to the hyporheic zone downstream of the dam showed 28e50% higher amoA richness and higher diversity than the other samples. All gene fragments sequenced from the samples grouped with sequences of the Nitrosospira type. Ordination of 16S rDNA tRFLP data revealed a two dimensional data structure, one axis of which had similar chemical correlation characteristics as the amoA model axis. Taken together, the results from this study suggest that the presence of the dam creates physical and chemical heterogeneity that may foster genetic diversity and community changes amongst ammonia oxidizing bacteria.

Atmospheric Research 120–121 (2013) 298–311

Title:Volatile organic compounds in suburban Ankara atmosphere, Turkey: Sources and variability
Authors:Sema Yurdakul, Mihriban Civan, Gürdal Tuncel
Abstract:In this study, concentrations of approximately 30 VOCs were measured, between January and June 2008 at a university campus in Ankara. Concentrations of measured VOCs are lower than corresponding concentrations reported for other cities in literature. Average concentrations of the measured VOCs ranged from 0.04 to 7.89 µg m-3. Benzene (2.18 µg m-3), toluene (7.89 µg m-3), ethylbenzene (0.85 µg m-3) and xylenes (2.62 µg m-3) (BTEX) were found as a major organics in suburban Ankara atmosphere. The measured VOCs also show well defined diurnal and weekday–weekend cycles. Toluene-to-benzene ratio (T/B) suggested that non-traffic sources can be important during summer months. The m,p-xylene-to-ethylbenzene ratio (X/E) pointed to transport of organic compounds from high-emission districts of the city. Positive matrix factorization applied to data revealed four sources, including gasoline exhaust, solvent evaporation, diesel emissions and a local laboratory source, contributing to VOC concentrations. Strengths of these sources, particularly solvent source, on total VOC concentrations showed seasonal differences. Source contributions on light and heavy VOCs were also different.

Journal of the Air & Waste Management Association, 63(10):1148–1162, 2013

Title:C5–C12 volatile organic compounds at roadside, residential, and background locations in Ankara, Turkey: Temporal and spatial variations and sources
Authors:Öznur Oğuz Kuntasal, Seda Aslan Kılavuz, Deniz Karman, Daniel Wang and Gürdal Tuncel
Abstract:Concentrations of 91 volatile organic compounds (VOCs) ranging from C5 to C12 were measured at three sites in Ankara, the capital of Turkey, in the summer of 2003 and winter of 2004. Samples were collected at roadside, residential and background stations at consecutive 4-hr intervals over a 24-hr period for six weeks in each season. Air samples were collected onto cartridges packed with Tenax TA and Carbopack B resins and analyzed by thermal desorption, followed by gas chromatography coupled to a mass selective detector (GC/MSD). Time resolved data provided information on ambient levels, temporal and spatial variations and sources of VOCs in Ankara. Toluene is the most abundant compound at all sites with and average concentration of 13.1 µg m-3. The mean concentrations of benzene are 12.6, 5.2, and 2.4 µg m-3 during winter at roadside, residential and background stations, respectively. Diurnal variation in the data together with toluene to benzene concentration ratio (T:B) that is close to 2.0 indicated the influence of traffic related emissions at residential and roadside stations during winter season. Higher T:B ratio observed at residential and background stations during summer period and correlation analysis indicated additional VOC sources. Temporal variations and low m,p-xylene to ethylbenzene ratio (mpX:E) indicated that transported air mass is the major VOC source influencing VOC concentrations measured at the background station.

Journal of Contaminant Hydrology 150 (2013) 77–92

Title:Modeling contaminant transport and remediation at an acrylonitrile spill site in Turkey
Authors:S. Sevinç Şengör, Kahraman Ünlü
Abstract:The August 1999 earthquake in Turkey damaged three acrylonitrile (AN) storage tanks at a plant producing synthetic fiber by polymerization. A numerical modeling study was carried out to analyze the groundwater flow and contaminant (AN) transport at the spill site. This study presents the application of a numerical groundwater model to determine the hydrogeological parameters of the site, where such data were not available during the field surveys prior to the simulation studies. The two- and three-dimensional transient flow and transport models were first calibrated using the first 266 days of observed head and concentration data and then verified using the remaining 540-day observed data set. Off-site migration of the contaminant plume was kept under control within the site boundaries owing to the favorable geology of the site, the characteristics of the local groundwater flow regime and the pumping operations. As expected, the applied pump-and-treat system was effective at high-permeability zones, but not fully effective at low-permeability zones. The results of long-term simulations for unconfined aquifer showed that the size of the plume in the high permeability zone shrank significantly due to the dilution by natural recharge. However, in the low permeability zone, it was not significantly affected. The study showed that accurate and sufficient data regarding the source characteristics, concentration and groundwater level measurements, groundwater pumping rates and their durations at each of the extraction points involved in the pump-and-treat system along with the hydrogeological site characterization are the key parameters for successful flow and transport model calibrations.

Desalination and Water Treatment, 51 (2013) 4171–4182

Title:Implementation of the European Union’s Nitrates Directive in Turkey
Authors:Ulku Yetis, Hande Yukseler, Simonas Valatka, Serkan Girgin Daiva Semeniene, Merih Kerestecioglu, Micheal Jacobsen
Abstract:The European Union (EU)’s Nitrates Directive (ND) (91/676/EEC) aims to reduce water pollution caused or induced by nitrates from agricultural sources and to prevent further such pollution. Turkey being a candidate country to EU requires heavy cost investments in achieving approximation with EU Environmental Acquis. This study provides a description of the technical measures and investment cost assessment related to the implementation of the ND in Turkey. As Turkey has not yet designated nitrate vulnerable zones (NVZs) according to requirements of the EU’s ND, three scenarios were developed to estimate the capital investments needed for implementation of the ND. Based on the developed scenarios, the low-cost scenario designating eight provinces as NVZs and requiring a total investment of EUR 270 millions for the period 2007–2023 has been selected by the Ministry of Environment and Forestry within the EU Integrated Environmental Approximation Strategy for Turkey.

JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY 5, 043 126 (2013)

Title:Biogas production from broiler manure, wastewater treatment plant sludge, and greenhouse waste by anaerobic co-digestion
Authors:E. Sarikaya and G. N. Demirer
Abstract:Inappropriate management of organic wastes can cause serious damage to the environment by polluting water and air, which can lower the quality of life. Ammonia and greenhouse gases (CH4 and CO2) emitted from the waste storage units can pollute the air. Inappropriate application of nitrogen and phosphorus on fields as manure can lead to eutrophication of surface water resources and pollution of soil and ground water. Conversion of the organic wastes to biogas through anaerobic digestion will, however, reduce the adverse impact on the environment and will contribute to a reduction in the consumption of fossil fuels. This study investigated the anaerobic digestion of broiler manure and greenhouse waste as well as anaerobic co-digestion of broiler manure and dewatered and non-dewatered wastewater treatment plant sludge for the production of biogas. To this purpose, biochemical methane potential experiments were performed. Moreover, the effects of nutrient and trace metal supplementation on the biogas yield were also examined. The results of this study indicated that (1) The obtained biogas values for broiler manure and greenhouse waste were very well in agreement with relevant literature values and comparable to that of food waste reported in the literature, respectively. (2) The experimental biogas production observed for codigestion of broiler manure and dewatered and non-dewatered wastewater treatment plant sludge is higher than literature values.

Journal of Environmental Management 128 (2013) 427-434

Title:Wastewater disposal to landfill-sites: A synergistic solution for centralized management of olive mill wastewater and enhanced production of landfill gas
Authors:Vasileios Diamantis, Tuba H. Erguder, Alexandros Aivasidis, Willy Verstraete, Evangelos Voudrias
Abstract:The present paper focuses on a largely unexplored field of landfill-site valorization in combination with the construction and operation of a centralized olive mill wastewater (OMW) treatment facility. The latter consists of a wastewater storage lagoon, a compact anaerobic digester operated all year round and a landfill-based final disposal system. Key elements for process design, such as wastewater pretreatment, application method and rate, and the potential effects on leachate quantity and quality, are discussed based on a comprehensive literature review. Furthermore, a case-study for eight (8) olive mill enterprises generating 8700 m3 of wastewater per year, was conceptually designed in order to calculate the capital and operational costs of the facility (transportation, storage, treatment, final disposal). The proposed facility was found to be economically self-sufficient, as long as the transportation costs of the OMW were maintained at 4.0 €/m3. Despite that EU Landfill Directive prohibits wastewater disposal to landfills, controlled application, based on appropriately designed pre-treatment system and specific loading rates, may provide improved landfill stabilization and a sustainable (environmentally and economically) solution for effluents generated by numerous small- and medium-size olive mill enterprises dispersed in the Mediterranean region.

Journal of Environmental Science and Health, Part A (2013) 48, 800–808

Title:Levels and sources of polychlorinated biphenyls in Ankara creek sediments, Turkey
Authors:NAZAN AKDUMAN ÖZYÜREK, KADIR GEDIK, ESRA ŞILTU and IPEK IMAMOGLU
Abstract:The spatial distribution, degree of pollution and major sources of polychlorinated biphenyls (PCBs) were evaluated in surficial sediments of Ankara Creek, located in the capital of Turkey and serving as one of the tributaries in the third largest watershed in Turkey. Sediment ?PCB concentrations analyzed on Aroclor and congener basis (seven indicator congeners) range from 5.5 to 777.6 ng g-1 and 3.7 to 743.3 ng g-1 dw as Aroclor and congener based concentrations, respectively. High concentrations of ?PCBs were observed in the samples located at the downstream sections of the Creek, after discharge from Ankara municipal wastewater treatment plant. Using a chemical mass balance receptor model (CMB), major sources of PCBs affecting the sediments were investigated. The CMB model identified Aroclor 1254 and 1260 to be the major PCB sources affecting sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.

Chemosphere 92 (2013) 821–827

Title:Impact of PCB-118 and transformer oil toxicity on anaerobic digestion of sludge: Anaerobic toxicity assay results
Authors:Devrim Kaya, Ipek Imamoglu, F. Dilek Sanin
Abstract:In this study, possible toxicity of increasing doses of PCB-118 and transformer oil (TO) on anaerobic sludge digestion was investigated. For this purpose, five different sets of reactors were prepared in which four different PCB-118 concentration (1, 10, 20, and 30 mg L-1) and three different TO concentration (0.38, 0.76, and 1.52 g L-1) were applied. Throughout the study, biogas production and composition, pH, TS, VS, and COD as well as PCB concentration were monitored. Toxicity was investigated by anaerobic toxicity assay (ATA) evaluating the reduction in methane production. A notable inhibition was observed mostly in 30 mg L-1 PCB reactors. A negative influence of PCB-118 and TO was observed on COD and solids removal. A maximum of 26.5% PCB-118 removal was attained.

Int. J. Global Warming, Vol. 5, No. 3, 2013

Title:Temporal variations of BTX compounds in Bursa/Turkey atmosphere
Authors:Sema Yurdakul, Mihriban Civan, Öznur Oğuz Kuntasal, Gürdal Tuncel
Abstract:Ambient concentrations of C2-C12 volatile organic compounds (VOCs) were measured at Bursa, which is the fourth largest city of Turkey. Two measurement campaigns were carried out between September 14 to November 6, 2005 and March 17 to May 10, 2006. Fifty one VOCs were regularly determined in each chromatogram. However, only BTX compounds are discussed in this study. Concentrations of BTX compounds showed well-defined diurnal cycles. Concentrations increased starting at 06:00 am in the morning, reaching to a maximum somewhere between 9:00 to 11:00 am. Then concentration decreased, until the evening rush hour, owing to increasing mixing height during day time. Then concentrations of BTX increased in the afternoon rush hour which extended to 08:00 pm. BTX concentrations remained low throughout the night. High binary correlations between BTX compounds suggest a common source, which are traffic emissions. However, other non-traffic sources were also found to be effective, for benzene in the November to March campaign.

Environ Monit Assess (2013) 185:5285–5293

Title:Characterization of lead-resistant river isolate Enterococcus faecalis and assessment of its multiple metal and antibiotic resistance
Authors:Yasin Aktan, Sema Tan, Bulent Icgen
Abstract:Contamination of surface waters has a direct impact on the public health of entire communities. Microorganisms inhabiting contaminated surface waters have developed mechanisms of coping with a variety of toxic metals and drugs. Investigations were carried out to isolate and identify lead-resistant bacteria from the river Kızılırmak along the city of Kırıkkale, Turkey. Of the 33 lead-resistant isolates, one isolate with a minimal inhibitory concentration of 1,200 mgL-1 was isolated and identified as Enterococcus faecalis by using biochemical tests and 16S rRNA sequencing. Lead-resistant E. faecalis isolate was found out to be resistant to other heavy metals like aluminum, lithium, barium, chromium, iron, silver, tin, nickel, zinc, and strontium and to drugs like amikacin, aztreonam, and gentamicin. E. faecalis harbored four plasmids with the molecular sizes of 1.58, 3.06, 22.76, and 28.95 kb. Plasmid profile analyses of cured derivatives revealed that the lead resistance ability of E. faecalis was still existing despite the elimination of all the plasmids. Moreover, the antibiotic resistance pattern of the cured derivatives did not demonstrate any change from the parental strain. Our findings indicated that the lead resistance genes of E. faecalis were located on the chromosomal DNA rather than the plasmid.

Journal of the Polish Mineral Engineering Society, 2013, Vol. 32, No:2, 63-67

Title:Nutrient enrichment of the anaerobic sludge by co-precipitating N and P in the mesophilic anaerobic digester
Authors:Uludağ-Demirer S., Duran M., Demirer G.N.
Abstract:Copper One of the techniques used for the stabilization of sewage sludge is anaerobic digestion. The effluent from anaerobic digesters usually requires further treatment since they contain high concentrations of N and P as a result of volatile solids destruction. In this study, a control was developed over the nutrient ions within the anaerobic digester by using substrate with high concentration of Mg2+ ion. The amount of Mg2+ ion added was determined based on the release rate of N and composition of magnesium ammonium phosphate. The results showed 50% removal of NH4+ and PO4 3- can be achieved without compromising the performance of the reactor in COD and VSS removal and biogas formation.