Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collections

Permanent URI for this collectionhttps://hdl.handle.net/20.500.13091/3

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Citation - Scopus: 2
Air Quality Status in Konya City Centre, Konya, Turkey During Pandemic Covid-19
(Institute of Physics, 2022) Yahaya, N. Z.; Jalaludin, J.; Toros, H.; Dursun, S.
High developed industry regions, provincial centers with a heavy traffic and dense populations with cold winters, using low-quality fossil fuel consumption have an effect on quality of life especially for people with respiratory diseases. The air quality data gathered from air monitoring stations for the City Center of Konya, Turkey were analysed statistically during the period when curfew due to the Covid-19 pandemic in 2020. The restrictions that cause the reduction of vehicle exhaust emissions, which are important factors in the formation of some air pollutants, are thought to be effective in improving the air quality as well as meteorological conditions are effective on the days when the air quality is analysed. It is thought that the reduction in HC, NOx, CO and PM emissions, which can be evaluated as exhaust emissions, will be an effective factor due to the restrictions of Covid-19 pandemic. Comparing between the 2019 and 2020 MCO data, we identified that most of the gases decreased with NO2 (-24 ?g/m3), SO2 (-24 ?g/m3), CO (-37 ?g/m3) and an increment of O3 of +50 ?g/m3 which indicates that the MCO and restricted of movement were give an impact to air quality levels in Konya City. The increase in O3 values were found by the existing of the sun rays in the atmosphere with the formation of O3 during the clean air period. © Published under licence by IOP Publishing Ltd.
Citation - WoS: 5
Citation - Scopus: 7
Alternative Approach for Safe Disposal of Dry Olive Pomace: Pyrolysis With/Without Physical Preprocessing
(SPRINGER, 2020) Dinç, Gamze; Yel, Esra
The aim of this study is to present an alternative approach for disposal by using pyrolysis for dry olive pomace (which is the leftover portion of raw olive pomace), which constitutes a problem in olive oil production facilities. In this context, dry olive pomace was pyrolyzed at 600 degrees C and two different pyrolysis durations: 5 degrees C/min heating rate without retention (total pyrolysis duration is 80 min) and 1 degrees C/min heating rate with 30-min retention after reaching target pyrolysis temperature (total pyrolysis duration is 550 min). Afterward, the effects of the dry olive pomace mixed with the olive mill wastewater and the pomace particle size during the pyrolysis process were evaluated in terms of pyrolysis product yields, inorganic contents of chars and organic fractions of bio-oil. While mixing of pomace within the wastewater resulted in an increase in the pyrolysis liquid, the effects of pomace particle size on pyrolysis product yields changed based on the pyrolysis conditions. A decrease in the particle size from 2 to 0.85 mm resulted in an increase in gas by 37.3% and a decrease in liquid by 37% at the pyrolysis process of 80 min. Furthermore, the decrease in the pomace size in grinding preprocess enhanced pyrolysis liquid quality in terms of a decrease in oxygenated compounds by 5-13% and an increase in aliphatic compounds by 7-20% at both pyrolysis durations. Consequently, dry olive pomace pyrolysis can be stated as one of the effective alternatives for safe disposal by converting waste into useful end products. Graphic abstract
Citation - WoS: 35
Citation - Scopus: 47
Application of Sequencing Batch Biofilm Reactor (sbbr) in Dairy Wastewater Treatment
(KOREAN INSTITUTE CHEMICAL ENGINEERS, 2019) Öztürk, Arzu; Aygün, Ahmet; Nas, Bilgehan
Application of lab-scale sequencing batch (SBR) and sequencing batch biofilm reactors (SBBR) for treatment of dairy wastewater was investigated under organic loading of 1,130-1,560 gBOD(5)/m(3)d. The main characteristics of the dairy wastewater were: pH=4.9, chemical oxygen demand (COD)=16,264 mg/l; biological oxygen demand (BOD5)=10,536 mg/l, PO4-P=342 mg/l; total nitrogen (TN)=224 mg/l. SBBR was filled with the Kaldnes K1 biocarrier at 30% of the volume of empty reactor. The SBR and SBBR were operated in fixed 24 h cycles, each consisting of 30 min fill up, 22 h aeration, 1.5 h settle, 30 min decant, and idle with a hydraulic retention time (HRT) of 8 days. Operational parameters such as pH, dissolved oxygen (DO), mixed liquor suspended solid (MLSS), solids retention time (SRT) and sludge volume index (SVI) were monitored during the whole cycle. The effects of these parameters on the COD, nitrogen and phosphorus removal were discussed in this paper. As a result, adding biocarrier to the reactor had a positive effect on organic with COD removal of 63.5% for SBR and 81.8% for SBBR and nutrient removal with ammonium removal of 66.0% for SBR and 85.1% for SBBR in treatment of dairy wastewater.
Citation - WoS: 36
Citation - Scopus: 44
Behavior and Removal of Ciprofloxacin and Sulfamethoxazole Antibiotics in Three Different Types of Full-Scale Wastewater Treatment Plants: a Comparative Study
(SPRINGER INTERNATIONAL PUBLISHING AG, 2021) Nas, Bilgehan; Dolu, Taylan; Koyuncu, Serdar
Due to the inadequate removal rates of drug residues in wastewater treatment plants (WWTP), the transition of these compounds into the environment has become a serious environmental problem for ecosystems and public health. In this study, occurrence, fate, and removal of widely consumed two antibiotics, ciprofloxacin (CIP) and sulfamethoxazole (SMX), selected from fluoroquinolone and sulfonamide groups, respectively were investigated in three different types of full-scale WWTPs located in Turkey. In this context, three WWTPs consisting of advanced biological treatment (large-scale), wastewater stabilization pond (WSP) (medium-scale), and constructed wetland (CW) (small-scale) were selected. While the detected influent concentrations of CIP in WWTPs ranged between the 218.6 and 2733.5 ng/L, maximum influent concentration for SMX in the same plants was determined as 179.7 ng/L. On the other hand, although it was detected at higher concentrations in raw wastewater, CIP was significantly removed in all WWTPs with a removal efficiency ranging from >77.1 to >98.2%. However, SMX showed quite different behaviors depending on the applied wastewater treatment processes in WWTPs in terms of total removal achieved. While treated in WSP well enough (>72.2%), a serious negative removal efficiency (-133.4%) was achieved for SMX in the WWTP having advanced biological treatment. Best removal performance obtained for the both antibiotic compounds among the investigated WWTPs was the medium-scale WSP consisting of anaerobic and facultative stabilization ponds, consecutively. This situation also supported the idea that WWTPs which are operated with higher solid retention time (SRT) and hydraulic retention time (HRT) contribute positively in the removal of antibiotic compounds.
Citation - WoS: 2
Citation - Scopus: 3
Biodegradability of Dissolved Organic Nitrogen in Yoghurt and Cheese Production Wastewaters
(Springer, 2022) Küçükçongar, Sezen; Gok, Z.; Oden, M. K.; Dursun, S.
Dissolved organic nitrogen can cause undesirable environmental problems in aquatic environments, such as eutrophication, nitrogenous disinfection by-product formation, and a decrease in the amount of dissolved oxygen. 25-80% of the total dissolved nitrogen (TDN) in the effluent of wastewater treatment plants is dissolved organic nitrogen (DON) form. As a result of these concerns, the biodegradability and management of DON is important issue for domestic/industrial wastewater treatment. Dairy products are widely consumed in Turkey and dairy industry wastewater has a high organic nitrogen content. In this study, the biodegradability of wastewater samples obtained from yoghurt and cheese production industries was investigated. The biodegradability of wastewater samples was determined by using a mixed bacteria culture and identified between 72.2 and 81.7% for yoghurt production wastewater and 19.1-20.1% for cheese production wastewater. BDON/TDN ratio was found as 65.4-71.9% and 16.5-17.5% ranges for yoghurt and cheese production wastewaters, respectively. Although both are released from dairy production, it has been determined that white cheese production wastewater has a very low biodegradability compared to yoghurt production wastewater. It is thought that the results of this study will contribute to the evaluation of the removal efficiency in other industrial facilities and domestic wastewater treatment plants.
Citation - WoS: 4
Citation - Scopus: 4
A Comparative Study of Free Chlorine Activated by Fe+2 and Uv C Light Catalysts in the Treatment of Real and Simulated Textile Wastewater: Optimization, Reactive Species and Phytotoxicity Assessment
(Elsevier, 2022) Türkyılmaz, Mehmet
A large amount of wastewater originating from the textile industry causes serious aesthetic and ecological problems in receiving environments due to its complex structure, variability in composition and high color content. Therefore, the main aim of this study is to integrate different cost-effective and environmentally friendly treatment processes to ensure the proper treatment and reuse of dye-containing wastewater before it is finally discharged into the environment. For this purpose, different synergistic activities of chlorine oxidant under Fe+2 and UV light catalysis were investigated in the removal of Acid Black 220 (AB 220), Bemacid Red (BR) and Bemacid Blue (BB) synthetic dyes used in the dyeing of polyamide textile products. The effects of pH, initial dye concentration, chlorine and Fe+2 dosage on dye degradation were investigated. Contributions of reactive species formed by using nitrobenzene (NB), t-butanol (TBA), and isopropanol (IPA) radical scavengers as specific probes were determined. Molar ratios were determined for optimum chlorine and Fe+2 concentrations and validation experiments were performed for different initial dye concentrations. Chlorine/Fe+2 was also applied to a real textile wastewater sample to which the specified dye recipe was applied. The effects of raw and treated textile wastewater on seed germination and plant growth parameters were determined using Lepidium sativum (L. sativum). The presence of iron ions and UV light has increased the removal, Chlorine/Fe+2 combination was chosen as the most suitable process due to initial investment and operating costs. The best performance was obtained at pH 3, due to the effect of pH on the dissociation of hypochlomus acid (HClO) and hypochlorite ion (ClO-). With the increase of Fe+2 and chlorine doses to the optimal level, the degradation efficiency increased and harmful effects were observed at high doses. Removal efficiencies of 76.1 %, 94.99 % and 97.36 %, respectively, were obtained for AB 220, BR and BB under optimized conditions. It was determined that hydroxyl radicals (center dot OH) have the highest contribution, dichloride radical (center dot Cl-2(-)) and chlorine (center dot Cl) radicals are similar and effective at a good level, but chlorine oxide radical (center dot ClO) cannot be considered as an oxidizing radical in the Chlorine/Fe+2 system. By applying Chlorine/Fe+2 to a real textile wastewater sample, high efficiency (>90 %) was obtained in terms of color removal. Considering the chemical oxygen demand (COD) removal, when compared to the efficiency of the process in color removal, it was seen that the removal was quite ineffective for AB 220 and BR, but was at an acceptable level in the real wastewater sample. The phytotoxicity experiments proved that raw wastewater is harmful and treated wastewater is much less toxic than the studied parameters and can be reused for various purposes. Therefore, the findings of this study showed that chlorination in the presence of Fe+2 is very effective, simple and fast in removing color from synthetic dye samples and real textile wastewater, and the treated wastewater is safe for reuse in terms of physicochemical parameters and toxicity.
Citation - WoS: 4
Citation - Scopus: 5
Comparative Study of Olive Pomace Pyrolysis With/Without Ultrasonic Preprocessing
(SPRINGER, 2020) Dinç, Gamze; Yel, Esra
Although ultrasonic preprocessing has been mainly used before olive pomace anaerobic process, there has not been any study of the effect of ultrasonic preprocessing on olive pomace pyrolysis. Therefore, in this study, ultrasonic was applied to the biomass as a preliminary process before the pyrolysis to examine its effects on both quality and quantity of the end products. Within this scope, pyrolysis gas, liquid, solid product yields, char inorganic contents and pyrolysis liquid organic fractions with or without preprocessing were investigated. Although the preprocessing resulted in a 5-10% decrease in bio-oil quantity, it enabled obtaining pyrolysis liquids with higher quality by increasing the percentage of the aliphatic compounds. Among the ultrasonic preprocessing conditions studied, it turned out that the one which applied 30 W power for 10 min was the best condition which provided the highest decrease in the percentage of the oxygenated compounds by 24% within the pyrolysis liquid. Under all ultrasonic preprocessing conditions, when compared to the bio-oils obtained without preprocessing, the biggest increase occurred in the organic compounds with carbon numbers between 9 and 15. Moreover, when the preprocessing was applied, the total number of compounds in the pyrolysis liquid increased by at least 8 and at most 49. While the ultrasonic preprocessing caused a decrease in the char quantity by less than 1%, the inorganic content of the chars altered based on the preprocess condition. The highest total inorganic quantity in chars was obtained at the pyrolysis after preprocessing at the lowest power and the shortest duration.
Citation - Scopus: 1
Designing Approach of Fiber-Reinforced Polymer Composite by Combination of Fibrillated Olive Pomace and Marble Powder
(Wiley-V C H Verlag Gmbh, 2022) Kawano, Tessei; Dinç, Gamze; Yel, Esra; Andou, Yoshito
The development of effective methods to utilize industrial and agricultural wastes is crucial from the perspective of a circular economy. Marble powder and olive pomace (OP), byproducts of olive oil production and marble processing, are considered one of the major sources causing severe environmental pollution, especially in Mediterranean countries. Herein, marble powder and OP are aimed to use as fillers in polypropylene (PP)-based polymer composite. In addition, fractionated OP is further fibrillated by a combination of mechanical grinding and ionic liquid treatment to enhance its performance as a reinforcement. After treatment for 24 h, the particle size decreases from about 2.1 to 1.1 mu m, and the lignocellulosic composition also varies due to the partial removal of hemicellulose. Finally, the compounding ratio of polymer composites consisting of PP, marble powder, fibrillated OP, and compatibilizer is optimized using response surface methodology (RSM) to achieve both high mechanical properties and high filler contents. Mechanical properties of polymer composite fabricated with optimum ratio are in excellent agreement with those predicted by RSM. Furthermore, the yield strength and Young's modulus of polymer composite are 33.9 MPa and 1.89 GPa, accordingly, which are higher than those of PP.
Determination of Atmospheric Ammonia Concentrations at a Wastewater Treatment Plant Using a Laboratory-Built Passive Sampler
(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2020) Kara, Gülnihal
Ammonia (NH3) concentrations were measured at nine locations using passive samplers where the malodor is intense in the central wastewater treatment plant (WWTP) in Konya, Turkey. A badge-type passive sampler suitable for both indoor and outdoor use was developed in the study to sample the NH3 gas released. The detection limit for a two-week exposure period is approximately 0.34 mu g/m(3). Validation of the passive samplers' performance was carried out by means of an experimental setup located in a laboratory environment. The field performance of the passive samplers was evaluated by analyzing samples simultaneously collected from nine different locations in the Konya WWTP during summer and fall periods. Higher NH3 concentrations were measured in the samples collected in summer than in those collected in fall. The 15-day average NH3 concentrations determined in the air samples collected from the plant inlet, pump unit 1, pump unit 2, bar screen, grit chamber, primary setting, and the sludge thickener (two locations) were determined to vary in the range of 21.58-61.70 mu g/m(3) for the samples collected in summer and in the range of 11.10-63.0 mu g/m(3) for those collected in fall. The highest concentrations were found in the bar screen, prior to the induction of chemical biological treatment.
Citation - WoS: 2
Citation - Scopus: 4
Development of a Highly Sensitive Sampler for Atmospheric Monitoring of 8-H Ambient Ozone Concentrations
(KOREAN SOC ENVIRONMENTAL ENGINEERS, 2020) Kara, Gülnihal
A new passive sampler reinforced with a composite membrane was developed to determine the 8-h ozone (O-3) concentration in ambient air. The composite membrane's water absorption capacity and porosity values were found analyzing its surface morphology using Scanning Electron Microscopy (SEM). Ozone adsorption performance of this sampler was tested by a badge-type sampler and automated measurement results. The developed sampler gave results equivalent (R-2 = 0.85) to those of automated O-3 monitors, and its experimental sampling rate was determined to be 55 cm(3)/min, approximately two times higher than the rate of the badge-type sampler. The detection limit obtained (5.3 mu g/m(3), 8 h sampling) in the study was adequate for winter-period samplings where in the ozone concentration is low in urban and semi-urban areas. Multimedia sampling results revealed that the results of the developed passive sampler had a high repeatability (RSD < 20%). Passive samplers reinforced with composite membranes were tested by badge-type samplers performing simultaneous samplings in land conditions. Area sampling results indicated that badge-type samplers were not suitable for 8-h area samplings, but tube-type samplers could be used.
Citation - WoS: 3
Citation - Scopus: 4
Effect of Fractional Distillation Pretreatment on Fuel Quality of Plastic Waste Pyrolytic Oils
(Elsevier B.V., 2022) Kalem Soğancıoğlu, Merve
Today, the amount of plastic waste is increasing due to the use of more plastic. Since these wastes are composed of complex chemical compounds, when they are stored, they are difficult to degrade in the air, water and soil environment and pose a serious environmental problem. One of the disposal methods of plastic waste is pyrolysis, where valuable and useful products are obtained. The pyrolytic oil products formed in the pyrolysis process can also be evaluated with their rich hydrocarbon compositions in the production of chemicals, energy production and fuel production. However, in order to evaluate this product in various fields, it would be good to improve the product quality with some pre-processes. In this study, the quality of HDPE and LDPE type pyrolytic oils was improved by fractional distillation. Distillation fractions usability as fuel was examined. By measuring the quality parameters of the bottom and distilled fraction obtained from the fraction process, its usability as gasoline (bottoms fraction) and fuel oil (distillate fraction) were evaluated according to TS EN 2177 and TS EN 228 standards, respectively. LDPE distillation efficiencies are higher than HDPE distillation efficiencies as LDPE pyrolytic oils are distilled more easily. The sulfur content of the distilled fractions obtained after distillation fell below limit values ??and showed a positive situation in terms of the use of distilled products as gasoline. HDPE300, HDPE400, HDPE500 and HDPE600 distillate fractions provided the standard / limit values ??given in TS EN 228 standards in terms of all parameters considered in the study. Similarly, in terms of all quality parameters considered, HDPE300, HDPE400 and LDPE500, LDPE600 and LDPE700 bottom fractions are compatible with the standard / limit values ??given in TS 2177 standards. © 2022 Elsevier B.V.
Citation - WoS: 3
Citation - Scopus: 4
The Effect of Particulate Matter Pollution of Saharan Dust Over Europe in May-2020: a Case Study of Karaman City Center, Turkey
(UNIV SINDH, NATL CENTRE EXCELLENCE ANALYTICAL CHEMISTRY, 2020) Sassi, Ashour; Ivanov, Serguei; Toros, Hüseyin; Dursun, Şükrü
Desert dust rising from the African region and covered very long distances with meteorological events can be an important source of pollution for many countries from time to time. Although dust and sand masses that remain in the atmosphere for a long time are known to be inert and stable, but studies show that they affect vegetative production by changes in precipitation and radiation regimes. It is important for natural phenomena and has also revealed their effects in regions over which the atmospheric transport occurs. The Sahara dust storm of mid-May 2020 has strongly, affected many European countries. The Sahara dust and hot air transport is reported over the Mediterranean region to the Balkans and further to Turkey. Depending on the climatic conditions, the Sahara dust may remain in some regions for longer period. Rainy and humid weather conditions slow down the flow of dust and increase the settling rate in that region. In such cases it creates mud-like precipitation accompanying with rain. In this study, Sahara dust pollution effect is investigated for a particulate event pollution with the use of measurements from the network system in all cities in Turkey. For this purpose, the values of Particulate Matter (PM) pollution are analysed before the desert dust reached Turkey, during the event and when it left the country. PM measurement values in Karaman province were examined and it was shown that the Sahara dust increased significantly in the period when it reached this region. Then, PM values were seen to come down to normal levels.
Citation - WoS: 9
Citation - Scopus: 7
Effects of Pyrolysis Conditions on Organic Fractions and Heat Values of Olive Mill Wastes Pyrolysis Liquid
(ASME, 2020) Dinç, Gamze; Işık, Ferda; Yel, Esra
Pyrolysis liquids can be evaluated in energy and material recovery. However, its characteristics and recovery potential highly depend on pyrolysis conditions. Olive pomace is lignocellulosic biomasses widely studied in the production of renewable energy and bio-based materials through pyrolysis, but there are no comprehensive studies about changes of pomace pyrolysis liquids' characteristics by pyrolysis conditions. Therefore, in this study, pyrolysis of olive pomace and various combinations of olive pomace with olive mill wastes at different heating rates, temperatures, and retention times was conducted to reveal effects of pyrolysis conditions on pyrolysis liquids' organic fractions. Moreover, heating values of organic compounds in pyrolysis liquids at different pyrolysis conditions were evaluated. All bio-oils comprises of aliphatic compounds (alkanes, alkenes, and alkynes), oxygenated compounds (acids, aldehydes, alcohols, esters, and ketones), and aromatic compounds (phenols and benzenes). The highest percentages of aliphatic compounds in olive pomace bio-oils were obtained at 600 degrees C, 5 degrees C/min heating rate with retention. A pyrolysis temperature increment leads to a decrement in H-type phenols and an increment in S-type and G-type phenolic compounds. Mixing pomace with olive mill wastes resulted in aliphatic compounds increment and oxygenated compounds decrement. Heating values of all bio-oils obtained under different pyrolysis conditions were found important for energy production. When pomace pyrolysis liqiuids' heating values changed between 2831 and 5100 cal/g, heating values of pomace-olive mill waste mixtures' bio-oils were found between 3300 and 5500 cal/g. Consequently, organic compounds in both pomace and pomace-olive mill bio-oils are valuable feedstocks and energy source in the number of product productions in various industrial processes.
Citation - WoS: 2
Citation - Scopus: 4
Enhanced Sewage Sludge Treatment Via Parallel Anaerobic Digestion at the Upper Mesophilic Level
(Academic Press, 2022) Erdirençelebi, Dilek; Ebrahimi, Gool Mohammad
Sewage mixed sludge (MS) digestion performance was ameliorated implementing the parallel digestion model for primary sludge (PS) and secondary sludge (SS) (waste activated sludge) as domestic sewage sludge fractions rich in oil and grease content at the upper mesophilic level (40 °C). Optimization of the organic loading rate (OLR) was conducted in parallel semi-continuous bench-scale digesters for PS, SS and MS. Comparatively evaluated performance and biosolid quality parameters were methane production rates, volatile solid (VS) reduction, oil and grease and nutrient content, dewaterability and electrical conductivity (EC). OLR optimization indicated different retention time needs for PS and SS stabilization and enabled 18% and 93% higher VS loading and reduction, respectively, compared to MS digestion. Inhibitory effect followed an ascending pattern as a result of OLR increase in each digestion line acting on the hydrolysis of proteinaceous matter and acetogenesis rather than methanogenesis. A high number of long chain fatty acids was detected in the raw sludges. The enhancing effect of the upper mesophilic temperature was significant in SS digestion with increased biodegradability, oil and grease removal and microbial growth compared to digestion at 35 °C. The parallel digestion system and upper mesophilic temperature proved a useful tool to enhance VS loading and reduction without worsening the stabilized biosolids’ dewaterability as a feasible model in the existing and prospective municipal wastewater treatment plants (WWTPs). The weakness of the MS digestion was diagnosed as the lower synthesis degree of biomass induced by the dilution of the substrate in PS by SS mixing which weakened the microbial tolerance to high OLR and inhibition. The output indicated the potential of parallel AD, importance of the optimization for OLR and temperature to advance the performance and flexibility of the sludge line practice in municipal WWTPs. © 2022 Elsevier Ltd
Citation - WoS: 40
Citation - Scopus: 46
Evaluation of Occurrence, Fate and Removal of Priority Phthalate Esters (paes) in Wastewater and Sewage Sludge by Advanced Biological Treatment, Waste Stabilization Pond and Constructed Wetland
(Pergamon-Elsevier Science Ltd, 2022) Nas, Bilgehan; Ateş, Havva; Dolu, Taylan; Yel, Esra; Argun, M. E.; Koyuncu, S.; Dinç, S.
Phthalate Esters (PAEs), detected in high concentrations generally in treated wastewater discharged from wastewater treatment plants (WWTPs), are important pollutants that restrict the reuse of wastewater. Investigating the fate of these endocrine-disrupting chemicals in WWTPs is crucial in order to protect both receiving environments and ecosystems. For this purpose, di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP) and benzyl butyl phthalate (BBP) in the group of PAEs were monitored in simultaneously both in wastewater and sludge lines of selected two nature-based WWTPs and one advanced biological WWTP. Although it was frequently stated that phthalates were significantly removed in WWTPs in many studies found in literature, negative removal efficiencies of selected phthalates in investigated WWTPs during the sampling period were observed generally in this study. One of the reasons for this concentration increase could be releasing of phthalates from microplastics in wastewater during the treatment process or the desorption of PAEs from treatment sludge. DNOP was the compound with the highest concentration increase at almost each treatment unit of the three WWTPs. On the other hand, total PAEs load was 1997 g d(-1) in advanced biological WWTP and adsorption onto sludge of PAEs were determined as 90%. The side-stream total load returned from the decanter supernatant was 0.02% of the total PAEs load coming to advanced biological WWTP from the sewer system. As a result of detailed statistical analysis, the correlation between raw wastewater and primary clarifier (PC) effluent was determined as an increasing linear relation for DEHP and DNOP. On the other hand, moderate and strong correlations were observed both between septic tank and constructed wetland (CW) processes with raw wastewater. In the waste stabilization pond (WSP), while a significant correlation was not found between the sludge line data, homogeneous variance, strong and moderate correlations were obtained in the wastewater line data. However, while mean differences for all investigated PAEs were not significant (p > 0.05) in the wastewater line, mean differences of DEHP (p < 0.05) were significant in the sludge line according to ANOVA analysis.
Citation - Scopus: 2
Evaluation of the Levels of Pesticide Residues in Wheat and Soil
(Parlar Scientific Publications, 2020) Tongur, Süheyla; Özcan, Z.
We know that the use of some types of pesticides is restricted throughout the world because of their harmful effects on the environment and health. Within the scope of the present study, pesticides used in Turkey and the potential for their residues to accumulate in the soil were investigated. The amount of residue in wheat was determined as ?g/kg, while that in the soil were determined as mg/kg. On average, 0.003 mg/kg residue was observed in the soil. Although biphenyl residue in wheat was 8.821 ?g/kg, isodrin residue in soil was 0.01 mg/kg. Although the values do not exceed the limits, maintaining levels close to the limits should be considered. These harmful compounds can survive for several years in the environment without degrading. This suggests their potential to accumulate in the ecosystem and, subsequently, in the food chain; therefore, these toxic pollutants must be used with discretion by conscientious scientists who are experts in pesticide use and their toxicity. When used in agriculture, those pesticides should be chosen that have the least environmental impact. Necessary precautions should be taken by comparing the amount of pesticide residue left in the soil and the cultivated products with limited values for specific periods. © by PSP
Citation - WoS: 11
Citation - Scopus: 13
Fate of Phthalate Esters in Landfill Leachate Under Subcritical and Supercritical Conditions and Determination of Transformation Products
(Elsevier Ltd, 2023) Ateş, Havva; Argun, Mehmet Emin
The hypothesis of this study is that the complex organic load of landfill leachate could be reduced by supercritical water oxidation (SCWO) in a single stage, but this operation could lead to the formation of some undesired by-products of phthalate esters (PAEs). In this context, the fate of selected PAEs, butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DNOP), was investigated during the oxidation of leachate under subcritical and supercritical conditions. Experiments were conducted at various temperatures (250–500 °C), pressures (10–35 MPa), residence times (2–18 min) and dimensionless oxidant doses (DOD: 0.2–2.3). The SCWO process decreased the leachate's chemical oxygen demand (COD) from 34,400 mg/L to 1,120 mg/L (97%). Removal efficiencies of DEHP and DNOP with longer chains were higher than BBP. The DEHP, DNOP and BBP compounds were removed in the range of −35 to 100%, −18 to 92%, and 28 to 36%, respectively, by the SCWO process. Many non-target PAEs were qualitatively detected in the raw leachate apart from the selected PAEs. Besides, 97% of total PAEs including both target and non-target PAEs was mineralized at 15 MPa, 300 °C and 5 min. Although PAEs were highly mineralized during SCWO of the leachate, aldehyde, ester, amide and amine-based phthalic substances were frequently detected as by-products. These by-products have transformed into higher molecular weight by-products with binding reactions as a result of complex SCWO process chemistry. It has also been determined that some non-target PAEs such as 1,2-benzenedicarboxylic acid bis(2-methylpropyl)ester and bis(2-ethylhexyl) isophthalate can transform to the DEHP. Therefore, the suggested pathway in this study for PAEs degradation during the SCWO of the leachate includes substitution and binding reactions as well as an oxidation reaction. © 2022 Elsevier Ltd
Citation - WoS: 4
Citation - Scopus: 7
Feasibility and Potential of Separate Anaerobic Digestion of Municipal Sewage Sludge Fractions
(WATER RESEARCH COMMISSION, 2020) Erdirençelebi, Dilek; Bayhan, Cansu
Feasibility of the separate anaerobic stabilization of primary (PS) and secondary (SS) sludge fractions produced in municipal wastewater treatment plants (WWTP) was studied at volatile loading rates (VLR) of 0.57-2.05 and 0.27-0.57 kg VS/(m(3).d) for PS and 55, respectively, corresponding to 16-30 and 14-28 d of hydraulic retention time (HRT). Laboratory-scale semi-continuous anaerobic reactors were operated at 35 degrees C. The operational performance and quality of the final stabilized sludge were monitored. PS and SS showed opposite thickening abilities exhibiting a need for direct feeding of PS to the digesters. Biodegradability was obtained as 52(+/- 1) and 40(+/- 5)% volatile solid (VS) removal for PS and SS, respectively. Optimum VIR was determined according to the highest methane yield (specific methane production), VS reduction and dewaterability of the stabilised sludge. An inhibitory effect was observed at higher VLRs in PS digestion inducing a gradual reduction in the methane yield and daily production. High oil and grease content was subject to a substantial reduction in PS digestion showing a dependency on HRT. Conversely, a considerable degree of augmentation took place in the stabilised SS with no correlation to HRT at values lower than 30 d. Efficient reduction in the oil and grease content improved dewaterability in stabilised PS whereas high oil and grease content prevented an improvement for stabilised SS. Major benefits were obtained as lower HRT and high stability with higher rnethane production arid fertilizing (N and P content) characteristics for digestion performance and stabilized SS, whereas direct feeding and higher HRT for PS digestion were determined as beneficial.
Citation - WoS: 14
Citation - Scopus: 17
Full-Scale Anaerobic Digestion of Sewage Sludges: Fate Evaluation of Pharmaceuticals and Main Metabolites
(Elsevier Ltd, 2023) Dolu, Taylan; Nas, Bilgehan
The occurrence and behavior of pharmaceuticals especially in sewage sludge have attracted great attention nowadays due to the intensive application of sewage sludge in agriculture in terms of the potential adverse effects of pharmaceuticals. Although anaerobic digestion is a well-developed and widely applied treatment process in terms of stabilization of sewage sludges and removal of organics, the treatment performances of this technology for different pharmaceutical subgroups are still not well known. In this study, the occurrence and seasonal variations of 45 pharmaceutical compounds consisting of 27 parent compounds and 18 main metabolites from 10 different therapeutic groups were investigated both in thickened and digested sludge generated in a large-scale urban wastewater treatment plant (WWTP). In this way, the seasonal removal performances of full-scale anaerobic digesters for parent compounds and metabolites have been determined and compared simultaneously. While the total pharmaceutical concentrations in the thickened sludge varied between 21.1 and 177.6 μg/kg seasonally, it was determined in the range of 21.5 and 88.8 μg/kg in the digested sludge. In the thickened sludge, the predominant group was found as antibiotics (35.9 %), while in the digested sludge, it was determined as anticonvulsants (31.3 %). Besides, seasonal relationships of parent compounds and metabolites both in thickened and digested sludges were evaluated statistically in terms of both occurrence and removal. In general, although the capacities for sorption onto sewage sludges were found as different, removal patterns of both parent compounds and metabolites in anaerobic digesters have been determined as quite similar. The removal performance of the anaerobic digesters showed great differences based on the investigated pharmaceutical subgroups. Although varies seasonally, while antibiotic (up to 82.9 %), NSAID (up to 70.9 %), and nerve stimulant (up to 89.6 %) groups tended to be treated in anaerobic digesters, negative removal efficiencies were determined for anticonvulsant (up to −242.9 %), steroid hormone (up to −155.3 %) and antidepressant (up to −5010 %) groups. While the total pharmaceutical treatment performances of anaerobic sludge digesters varied between −78 % (in summer) and 65 % (in winter) seasonally, it has been determined as 28.5 % annually. Therefore, it has been determined in this study that the pharmaceutical treatment performance of full-scale anaerobic digesters is not effective enough. © 2022 Elsevier Ltd
Citation - Scopus: 3
A Global-Scale Assessment of Water Resources and Vegetation Cover Dynamics in Relation With the Earth Climate Gradient
(Springer Nature, 2022) Sohoulande, C.D.D.; Awoye, H.; Nouwakpo, K.S.; Doğan, Selim; Szogi, A.A.; Stone, K.C.; Martin, J.H.
Changes in the terrestrial climate and the rapid growth of the world population cause pressures on water resources and natural vegetation covers. Given the importance of these resources for the survival of both human communities and the terrestrial ecosystems, it is critical to envision research-based strategies for their preservation. However, studies that assessed changes in vegetation and freshwater resources have preferentially focused on the marginal role of human, precipitation, and temperature, while neglecting the connection with global climate gradient. Yet, a full understanding of the ongoing changes in the terrestrial vegetation and water resources is needed to develop effective strategies for preserving these resources. In an effort of contributing to the understanding of these changes, this study investigates the actual patterns in the terrestrial land water masses and vegetation covers in relation with the earth climate gradient. Especially, climate aridity indices are estimated and used to highlight climate classes. Trends analyses of monthly leaf area index and land water storage anomalies show different signals depending on the earth latitude bands. Results show 36.5% of the continental lands have experienced a decrease of water resources, but these areas do not necessarily encompass regions with decreasing trends of vegetation cover. Chi-square statistics indicated significant connections between climate classes and vegetation cover trends as well as climate classes and land water storage trends. This study concludes the global climate gradient marginally regulates the dynamics of water resources and vegetation covers. Yet, examples show human-induced changes can supersede this overall connection in certain regions of the globe. © 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.

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