PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collections

Permanent URI for this collectionhttps://hdl.handle.net/20.500.13091/5

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Now showing 1 - 7 of 7

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 - 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: 5
Citation - Scopus: 6
Nickel Adsorption From Waters Onto Fe3o4/Sugar Beet Pulp Nanocomposite
(Taylor & Francis Inc, 2022) Sadat, Sayed Mohammad Osman; Küçükçongar, Sezen; Türkyılmaz, Mehmet
In this study the magnetic nanocomposite material was synthesized with Fe3O4 impregnated to sugar beet pulp using chemical precipitation technique. Ni(II) removal performance of magnetic nanocomposite was investigated under different environmental conditions such as contact time, adsorbent dose, pH, initial heavy metal concentration, etc. The experimental studies have shown that, 81.2% Ni(II) removal efficiency was achieved at optimal conditions (25 mg/L initial Ni(II) concentration at 40 minute contact time, 200 rpm shaking speed, 5 g/L nanocomposite dose and pH 6.6). Freundlich and Langmuir isotherm experiments were performed and correlation coefficients were determined as 94.5% and 99.4%, respectively. The maximum adsorption capacity of material was achieved as 9.36 mg/g. These findings indicate that the adsorption that takes place is a monolayer process. The results of the pseudo-second order kinetic model (R-2 = 0.9947) indicate the chemisorptions process is used for Ni(II) removal using the electrostatic interaction. Thermodynamic studies illustrated that Ni(II) adsorption onto nanocomposite are exothermic and causes a decrease in the entropy. The adsorption of Ni(II) ions is non-spontaneous except for at low temperature and low initial concentrations. Nanocomposite characterization was illuminated with XRD, FT-IR, BET, TGA, TEM, SEM/EDX analysis. NOVELTY STATEMENT In this study, it was aimed to synthesis new adsorbent using sugar beet pulp together with Fe3O4 under suitable conditions, obtain a magnetic nanocomposite, and examine the reusability and recovery properties of the produced material. The use of industrial wastes as an adsorbent material provides both a solution to the problem of the removal of wastes and a reuse method for the use of wastes as a low cost adsorbent for a useful purpose. Therefore, it has two advantages: There is a need to investigate the feasibility of investigating all possible industry-based cheap adsorbent sources as well as the removal of heavy metals for the production of a reliable and harmless adsorbent.
Citation - WoS: 53
Citation - Scopus: 58
Occurrence, Loadings and Removal of Eu-Priority Polycyclic Aromatic Hydrocarbons (pahs) in Wastewater and Sludge by Advanced Biological Treatment, Stabilization Pond and Constructed Wetland
(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2020) Nas, Bilgehan; Argun, Mehmet Emin; Dolu, Taylan; Ateş, Havva; Yel, Esra; Koyuncu, S.; Kara, M.
Eight polycyclic aromatic hydrocarbon (PAH) compounds which have been accepted as priority micropollutants by European Union (EU) were analyzed both in wastewater and sludge lines throughout three full scale (located in city, sub-province and village) WWTPs during 12-month sampling period. Investigated WWTPs have different treatment types including advanced biological treatment, stabilization pond (SP) and constructed wetland (CW). Removal efficiencies for total PAH compounds varied from 48% in CW to 85% in advanced biological treatment plant. The maximum concentrations of 360-2282 ng/L observed for naphthalene in raw wastewater were decreased to 103-370 ng/L by treatment processes. Minimum concentration were detected for benzo(k)fluoranthene (B[k]F) and benzo(g,h,i)perylene (B[g,h,i]P) ranged between 8 and 12 ng/L and 19-33 ng/L, respectively. While minimum removal efficiencies were obtained for B[k]F and B[g,h,i]P maximum removal efficiencies were obtained for naphthalene in all WWTPs. PAHs present in minimum and maximum levels in the sludge samples were detected as 54 and 6826 ng/g for the B[g,h,I]P and naphthalene, respectively. Considering the removal mechanisms, PAHs have been determined to be removed by biodegradation or vaporization up to 84% and by settling (adsorption onto sludge) up to 2%. The greatest portion (99%) of naphthalene and anthracene were determined to be biodegraded or vaporized in biological treatment due to their low molecular weights. On the other hand, mechanism of adsorption onto sludge was determined as negligible for these two compounds. In addition, approximately 14% of PAHs were discharged to the receiving environment. Among the different WWTP types investigated, advanced biological treatment was found to be the most efficient plant for the removal of PAH compounds.
Citation - WoS: 36
Citation - Scopus: 42
Removal of Pahs From Leachate Using a Combination of Chemical Precipitation and Fenton and Ozone Oxidation
(IWA PUBLISHING, 2018) Ateş, Havva; Argun, Mehmet Emin
In this study, six emerging pollutants, belonging to the polycyclic aromatic hydrocarbons (PAHs) group, found in landfill leachate were investigated for their removal by sequential treatment processes including chemical precipitation (CP), Fenton oxidation (FO) and ozone oxidation (OO). Each treatment process was run under different conditions using an experimental design program. Optimization of both CP and FO processes was designed based on the measured values of the residual chemical oxygen demand (COD) of the samples analyzed. The analysis of variance test was applied to the obtained results for determination of statistical significance of the model. Removal efficiencies of micropollutants were determined in the optimal conditions both for CP and FO processes. Samples obtained after these processes were treated with different pH and ozonation times for observing the performances of ozonation on micropollutant removal under different operating conditions. In this study, the removal of acenaphthylene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene micropollutants was investigated. The values obtained for PAHs in leachate were determined to be above 10 ppb. In the CP process, the removal efficiencies for PAHs were ranged between 6% and 40% except for pyrene. Removal efficiencies of all micropollutants with FO were over 70% except for fluorene (55%). The removal efficiencies of the investigated micropollutants were 80-100% as a result of consecutive treatment processes including CP, FO and OO respectively.
Citation - WoS: 9
Citation - Scopus: 11
Simultaneous Removal of Gaseous Benzene and Toluene With Photocatalytic Oxidation Process at High Temperatures Under Uvc Irradiation
(Springer Heidelberg, 2022) Dursun, Şükrü; Ayturan, Zeynep Cansu
Organic air pollutants represent many different pollutants, including persistent toxic organics and volatile organic compounds (VOC). The VOC group includes about 150 different compounds, the majority of which are considered harmful and toxic to human health. Considering all these features, the removal of VOC is of great importance. According to the Industrial Air Pollution Control Regulation, VOCs in flue gases are classified, and the limit value for the most dangerous group is specified as 20 mg/m(3) according to the degree of damage. From past to present, many different removal technologies have been developed and continue to be developed. Removal of pollutants at low concentrations by conventional methods is more inadequate than those above certain concentrations. Photocatalytic oxidation (PCO) is one of the technologies used for VOC removal recently. It has been determined that many different organic pollutants can be removed with this method. Within the scope of this study, the removal of benzene and toluene pollutants, which are two important VOCs frequently encountered in flue gases, by the photocatalytic oxidation method has been studied under UVC irradiation. In this study, a new photocatalyst by doping silver (Ag), a noble metal, and nickel (Ni), one of the transition metals, on TiO2 nanoparticles was developed and a laboratory-scale reactor system was designed. Many experiments were carried out by changing the system parameters such as ambient temperature (120 degrees C, 150 degrees C, 180 degrees C), humidity (25% and 50%), and percentage of Ag and Ni doping on TiO2 (0.5%, 1%, 2.5%, %5) and the most successful conditions for the removal of benzene and toluene contaminants were tried to be determined based on the results obtained. When all experiments carried out within the scope of this study were considered, the average removal efficiency for benzene was found as 89.33%, while the average removal efficiency for toluene was 88.23%. According to the obtained results, the most suitable conditions for the simultaneous removal of benzene and toluene pollutants with photocatalytic oxidation method under UVC light were determined as 120 degrees C temperature, 25% humidity, and 0.5% doping photocatalyst.

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Browsing PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collections by Department "Fakülteler, Mühendislik ve Doğa Bilimleri Fakültesi, Çevre Mühendisliği Bölümü"