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Öğe Co-combustion dynamics and products of textile dyeing sludge with waste rubber versus polyurethane tires of shared bikes(Elsevier Sci LTD, 2023) He, Yao; Chen, Xi; Tang, Xiaojie; Chen, Siqi; Evrendilek, Fatih; Chen, TaoThe co-combustions of major waste streams such as textile dyeing sludge (TDS) and waste tires of shared bikes may reduce the dependence on fossil fuels, as well as enhance their circular management and the recovery of their value-added products. In this study, the ash-to-gas products, interaction effects, and reaction mechanisms of the co-combustions of TDS and waste tires were characterized. The mono-combustions included the three stages of water evaporation, volatiles release, and mineral decomposition for TDS and the five stages for both rubber (RT) and polyurethane (PUT) tires. The three substages of the main stage of volatiles release for TDS had the activation energy of 124.5, 144.9, and 167.5 kJ/mol and were best explained by the reaction mechanism models of D3, D5, and F2, respectively. The (co-)combustion performance indices rose with the increased heating rate. The blend of 25% TDS with 75% RT (TR) and 75% PUT (TP) led to the best co-combustion performance according to comprehensive combustion index, with TP outperforming TR. The co-combustions of TP and TR reduced the activation energy required for the main devolatilization stage reaction. There was no significant difference in the main reaction mechanisms between the co-combustions. The interaction between TDS and waste tires reduced the applied energy required for the main devolatilization stage. The co-combustions at the low temperature produced O-H, CH4, CO2, CO, SO2, NO, carbonyl products, olefin products, and ketones. The cocombustions increased the production of C-H, reduced SO2 release and the viscosity of their ashes, promoted the complete combustion of substances, and alleviated the scale and sintering issues regardless of TP versus TR and caused the early release of NO from TP. According to the thermodynamic equilibrium simulations, the TR cocombustion promoted the retentions of Ca, S, Si, and Fe, in particular, the fixation of S. The addition of PUT enhanced the combination of Ca and Si into CaSiO3. The optimization based on the artificial neural networks pointed to the temperature range of 400-800 oC and the TR co-combustion as the optimal operational conditions.Öğe A novel hybrid optimization model to determine optimum water resources for water supply of residential areas(Elsevier, 2023) Eryiğit, MiraçIn this study, a new hybrid model was improved by combining heuristic and numerical optimization algorithms to decide on optimum water resources based on their costs in the water supply. The purpose of the hybrid model is to reach a best result in the shortest time by simultaneously searching global and local minimums. Therefore, the steepest descent (SD) algorithm (numerical optimization method) was embedded in the classical modified clonal selection algorithm (the classical modified Clonalg) (one of artificial immune systems, heuristic optimization technique). This hybridization allows the SD algorithm to search local minimums while the classical modified Clonalg is searching a global minimum. The hybrid optimization model was applied to the cost objective function depending on distances and piezometric head differences between the water resources and destination. A scenario consists of five hypothetical water resources and one residential area/settlement. Herein, the aim is to satisfy the water demand of the residential area with a minimum cost from the water resources. The cost objective function was also minimized by the regular model (the classical model) according to the scenario, and their results were compared. Both models were run ten times for testing their stabilities. According to the results, the hybrid model is better than the regular model in terms of run time and stability. The hybrid model found a minimum cost for the water supply in a shorter time (in half) in comparison with the regular model in all runs.Öğe Appraising the characteristics of particulate matter from leather tanning micro-environments, their respirational risks, and dysfunctions amid exposed working cohorts(Springer, 2023) Sarwar, Fiza; Alam, Khan; Öztürk, Fatma; Koçak, Mustafa; Malik, Riffat NaseemLeather tanneries are known for chemical laden work environments and pulmonic complaints among workers. This study presents an analysis of tannery micro-environments emphasizing on size-based variation in composition of particulate matter and consequent respiratory dysfunctions. Qualitative (FTIR, SEM-EDX) and quantitative assessment (elemental composition, carbon forms) of PM10 and 2.5 has been employed. For lung function evaluation of workforce, spirometry with ATS proprieties was used. The peak concentrations of both PM10 and 2.5 have been found at PU, FU, and B&S. The LTCR for only Cr is high for both PM2.5 and PM10. HQ was high for Al, Cr, and Mn for both PM sizes. The maximum organic and secondary organic carbon in PM10 was found at FU and in PM2.5 at PU. The varied PM composition included carbohydrate (B&S, WMO), ether (S&S, P&S) and hydroxyl (B&S, S&S, P&S), proteins, polyenes, vinyl groups (S&S, P&S, FU), alcohols (PU and FU), and aldehyde present at PU. These results were armored by high organic and total carbon concentrations for the same sites. Therefore, PM are classified into biogenic (carbonaceous: microbial and animal remains) from PU and WMO, incidental (industrial, mixt physico-chemical character) from PU, FU, WMO, B&S and P&S, and geogenic (crustal mineral dust) from RHT, B&S, PU, and P&S. Furthermore, increase in metal concentrations in PM10 (Cr, Mn, Co, Ni, V, As, Be, Ba, and Cd) and PM2.5 (As, Pb) while TC, OC, and SOC in PM2.5 caused depreciation overall lung function. The exposure to biogenic and incidental PM nature are key cause of pulmonic dysfunction.Öğe Hidden realities: Food waste from servings in mini size packaging(Pergamon-Elsevier Science Ltd, 2024) Doğdu, Gamze; Pekdemir, Turgay; Lakestani, Sanaz; Karabörk, Şeyda; Çavuş, OsmanThis paper provides data obtained from real-life measurement of the Food Waste (FW) associated with the services offering food in mini size (9-20 g) single-use packaging representing the impact of the difficulties in emptying the food from such packages and service characteristics. We collected discarded such food packages from commercial public eateries (a time-share thermal town, student canteen, and student refectory), quantified FW, and subjected data to statistical analysis regarding the eatery places, package characteristics, and food type. The results suggest that service style, packaging, and consumer wastefulness can cause 10-47 %, 3-11 %, and 5-37 % FW, respectively, indicating hidden part of the wastage iceberg from mini size food portions with vast implication on the food and relevant packaging sustainability. Regarding the packing, the dominant cause of FW is difficulties in emptying the food, such as the shape, size, depth, width, and material of the package. Concerning the consumer wastefulness, our measurements seem to imply that the groups with relatively higher affluency creates more FW. Our results will prove to be highly beneficial in both promoting efforts to raise awareness of not only consumers but also industry players and decision makers on the sustainability for food and relevant packaging material.Öğe An innovative solution for the treatment of poultry industry wastewater with advanced hybrid technology sono-photocatalysis(Global Network Environmental Science & Technology, 2023) Doğdu, GamzePoultry slaughterhouse wastewater (PSWW) is a crucial concern fundamentally due to extensive generation and related substantial amounts of recalcitrant organic content due to high COD and oil and grease (O&G) levels. Hybrid advanced oxidation processes are promising, green, and innovative options to treat various industrial wastewater; to date, this potential has not been implemented to high -strength wastewater from the poultry industry. This work aims to investigate the combination of ultrasound and photocatalysis processes in the treatment of poultry slaughterhouse wastewater for the removal of COD and O&G under different operating conditions such as catalyst type (TiO2 and ZnO), irradiation type (UVA365 and UVC254), catalyst dosage (0.5-2.5 g/L), pH (2-10), hydrogen peroxide concentration (0-10 mM) and operation time (30-180 min). Taguchi's experimental design based on the L36 orthogonal array was adequately applied to optimize the process. The finding results presented that ZnO concentration of 2.5 g/L, pH 2, and operation time of 180 min under UVC254 were optimum parameters to achieve maximum COD removal while, ZnO concentration of 1.5 g/L, pH 6, H2O2 concentration of 5 mmol/L and operation time of 30 min under UVC254 were optimum parameters to achieve maximum oil and grease removal. With these optimum conditions, the best attained COD and O&G removal yields were 54% and 99%, respectively.Öğe Growth modelling of saccharomyces cerevisiae and simulation of pyrite ash X-ray diffraction patterns(Hrvatsko Drustvo Kemjijskih Inzenjera I Tehnologa, 2022) Ermurat, YakupSaccharomyces cerevisiae was incubated in media comprising pyrite ash for growth modelling studies, and the samples of pyrite ash were analysed using X-ray diffraction (XRD) to simulate profiles. The sigmoidal modelling curves in 3D growth graphs were presented alongside numerical error computations and graphs. Simulation of XRD spectra of the pyrite ash using diffraction profiling functions were conducted for designing a combined experimental process. The von Bertalanffy growth model function yielded the lowest relative error value of 11.56 %, and the exponential model estimation produced the low numerical error percentages as Euler's error of 4.8 %, and Heun's error of 5.36 %. Gaussian and lorentzian approximations were applied to shape the data of the XRD profiles of sulphur-containing samples, and well-described graph simulations were obtained using the Gaussian estimation.Öğe Technical and environmental feasibility of gas-solid decontamination by oxygen-enriched co-combustion of textile dyeing sludge and durian shell(Elsevier Sci LTD, 2022) Liu, Hui; Liu, Jingyong; Huang, Hongyi; Wen, Yixing; Evrendilek, Fatih; Ren, Mingzhong; He, YaoThe urgent need to reduce greenhouse gas emissions entails a cleaner waste treatment technology. The oxy-fuel co-combustion can recover energy and reduce the waste stream. This study aims to fill the knowledge gaps about the impacts of atmosphere type, blend ratio, oxygen concentration, and their interactions on the co-combustion behaviors and products of durian shell (DS) and textile dyeing sludge (TDS). The higher oxygen concentration reduced the reaction temperature, advanced the inhibition temperature, and promoted the decomposition rate with no significant effect on the residual mass. The N2 atmosphere resulted in a better co-combustion performance than did the CO2 one. The increased addition of DS improved the co-combustion performance. At the same oxygen concentration, the maximum absorption intensity of CO was higher in the N2/O2 than CO2/O2 atmosphere. Similarly, the maximum absorption intensities of C-O(H) and C=O were higher in the CO2/O2 than N2/O2 atmosphere. The co-combustion did not increase the issues of slagging and scaling. The main components of DS, TDS, and their blend ash with 50% DS and 50% TDS included MgO, Fe2O3, and Fe2O3, respectively.Öğe Oxy-fuel co-combustion dynamics of phytoremediation biomass and textile dyeing sludge: Gas-to-ash pollution abatement(Elsevier, 2022) Wu, Xieyuan; Liu, Jingyong; Wei, Zebin; Chen, Zihong; Evrendilek, Fatih; Huang, WenxiaoThe environmental pressures of major wastes in the circular economies can be abated leveraging the complementarity and optimal conditions of their co-combustion. The oxy-fuel co-combustion of phytoremediation biomass of Sedum alfredii Hance (SAH) and textile dyeing sludge (TDS) may be a promising choice for sustainable CO2 capture and a waste-to-energy conversion. This study characterized and quantified their co-combustion performances, kinetics, and interactions as a function of blend ratio, atmosphere type, and temperature. With a focus on the characteristic el-ements of SAH (Ca, K, Zn, and Cd) and TDS (Al and S), changes in the mineral phases and ash melting and slagging trends of K2O-Al2O3-SiO2 and CaO-Al2O3-SiO2 systems were quantified. The Zn and Cd residual rates of the co-combustion of 75% SAH and 25% TDS rose by 58.52% and 5.93%, respectively, in the oxy-fuel atmosphere at the 30% oxygen concentration, relative to the mono-combustion of SAH in the air atmosphere. The co-combustion in the oxy-fuel atmosphere at the 20% oxygen concentration delayed the release peaks of SO2, C2S, and H2S, while the Ca-rich SAH captured S in TDS through the formation of CaSO4. Our findings provide new and practical insights into the oxy-fuel co-combustion toward the enhanced co-circularity.Öğe Organic pollutant exposure and health effects of cooking emissions on kitchen staff in food services(Wiley-Hindawi, 2022) Varlı, Semra Navruz; Bilici, Saniye; Arı, Akif; Arı, Pelin Ertürk; İlhan, Mustafa Necmi; Gaga, Eftade EmineThis study was conducted to determine the exposure and health risk to cooking fumes of a total of 88 volunteer kitchen staff aged between 18 and 65 years working in five different kitchens in Ankara. Gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs), and volatile organic compound (VOCs) concentrations were evaluated in the indoor air of 5 kitchens. Serum malondialdehyde (MDA) and superoxide dismutase (SOD) levels were analyzed to determine the oxidative damage as a result of the exposure to cooking fumes among the cooks and waiters. Significant positive relationships were found between serum MDA levels of the hot kitchen workers and indoor chrysene (Chr), indeno(1,2,3-c,d)pyrene (Ind), and total VOC levels. Although the carcinogenic risks estimated for the exposed population were between the acceptable/tolerable levels, the hazard quotient (HQ) estimated for the exposure to indoor benzene exceeded the safe level. The results of the study revealed that exposure to organic pollutants in indoor air may be a risk factor for the development of oxidative stress, especially in hot kitchen workers. The importance of efficient ventilation in the kitchen has been pointed out to reduce health risks caused by cooking fumes.Öğe Combustion mechanism and ash-to-gas products of star anise residues: Atmosphere and temperature dependencies and joint optimization(Elsevier Sci LTD, 2023) Chen, Tao; Li, Xiaoming; Liang, Jiayu; Evrendilek, Fatih; Wen, Xiaocui; Lin, Sen; Liu, JingyongThe efficient energy utilization of biomass is still being explored to lessen the heavy dependence on fossil fuels. This study aimed at characterizing the combustion behaviors, performances, ash-to-gas products, reaction mechanisms, and joint optimization of star anise (Illicium verum Hook. f. (SA)) residues in response to temper-ature, heating rate, and atmosphere type (N2/O2 versus CO2/O2). The main combustion stage of SA was between 150 and 580 degrees C. The combustion performance indices were higher in N2/O2 than CO2/O2. The estimated acti-vation energy varied between 168.26 and 241.77 kJ/mol. F1, F1.5, A1.5, and A2 well described the most likely reaction mechanisms. The energetically and environmentally multiple objectives were simultaneously optimized using artificial neural networks with the operational inputs of temperature and atmosphere type. The relative importance of the atmosphere type to the gaseous products were thus: aromatics < C-O < C--O < CO < CO2 < H2O < CH4. The combustion gaseous products were the same in both atmospheres. The SA ash was of K type with a high deposition risk in both atmospheres. Changing N2 to CO2 reduced the tendency of ash scaling and slagging.Öğe Oxy-fuel and air atmosphere combustions of Chinese medicine residues: Performances, mechanisms, flue gas emission, and ash properties(Pergamon-Elsevier Science Ltd, 2022) Chen, Zhiyun; Liu, Jingyong; Chen, Huashan; Ding, Ziyi; Tang, Xiaojin; Evrendilek, FatihThis study aims to quantify the combustion performances, mechanisms, and ash characteristics of Chinese medicine residues (CMR) in the air and oxy-fuel atmospheres. The CMR combustion underwent water loss (<150 degrees C) and the decomposition of the main organic components (150-560 degrees C). The CMR combustion performed better in the air than 8-2/CO2-O-2 atmosphere experimentally, as was also evidenced by the joint optimization based on artificial neural network. The rising oxygen fraction of the three oxy-fuel atmospheres improved the oxy-fuel combustion performance by 76.7%. The air atmosphere led to a higher activation energy at the start (275.15 kJ/mol) and end (520.91 kJ/mol) of the main reaction, while the oxy-fuel atmosphere resulted in a higher activation energy of 400.22 kJ/mol with the conversion degree of 0.7. Its reaction mechanism followed the sequence type (Fn) and changed from F3 to F2 in the 8-2/CO2-O-2 atmosphere and from F2.4 to F2.5 in the air atmosphere and flue gas functional groups included CO2, H2O, C=O, and C-(O)H. The oxy-fuel atmosphere was more prone to slagging than the air atmosphere. The ash in the oxy-fuel atmosphere was easily formed calcium carbonate and calcium hydroxyphosphate. (C) 2021 Elsevier Ltd. All rights reserved.Öğe Optimal management of multiple water resources by a heuristic optimization for a water supply in the desert cities of Western Iraq(Desalination Publ, 2023) Eryiğit, Miraç; Sulaiman, Sadeq Oleiwi; Najm, Abu Baker Ahmed; Mhedi, Nebras MahmoodIn the present study, two different cost-benefit functions in the related literature were compared to decide on optimum water resources for supplying the water of Rutba City, which is located in western Iraq within the administrative Anbar Province. One of the two objective functions is directly based on differences between daily incomes (water charge/m3) and expenses (electricity price of pump stations) (maximization) while another one is based on the distances and the piezometric head differences between the water resources and the city (minimization). The objective function used by Carini et al. [2] was modified by considering the pump flow. It was solved by the heuris-tic optimization model, which uses the modified clonal selection algorithm (the modified Clonalg), one of the artificial immune systems under the same constraints of the required daily water demand of the city, pump discharge capacities, and limits of withdrawing water from the water resources. After running the model, it was seen that the results of the objective function as a total daily net income obtained by Eryigit and Sulaiman [1] are better than the results of the modified func-tion of Carini et al. [2] (2,960 and 2,950 USD/d, 2,225 and 2,212.5 USD/d for the first and second six months of the year, respectively) for Rutba City in regards to the cost-benefit relationship.Öğe Source identification of water-insoluble single particulate matters in rain sequences(Turkish Natl Committee Air Pollution Res & Control-Tuncap, 2022) Berberler, Ercan; Gemici, Betül Tuba; Özel, Halil Barış; Demir, Tuğçe; Karakaş, DuranIn this study, eight independent rainfall events were sampled sequentially from September 20, 2019 to June 15, 2020, in Bartin province located on the western Black Sea coast of Turkey. Manually collected volume-based sequential samples were analyzed for pH and water-soluble ions involving F-, Cl-, NO3-, SO42-, PO43-, Na+, K+, NH4+, Mg2+, and Ca2+. Total trace and major elements (sum of soluble and insoluble fractions), and elemental and organic carbons (EC and OC) contents of the sequential samples were measured. Water-insoluble particulate matter in the sequential samples were characterized for their sizes, morphologies, and compositions by using Scanning Electron Microscopy Energy Dispersive X-Ray Spectrometry (SEM-EDS) and a particle size analyzer. Results of SEM-EDS, particle size distributions, chemical analyses, and the upper atmospheric back trajectories were used to apportion the sources of the water-insoluble single particulate matters in sequential rain samples. Using the proposed method, iron-steel facilities, and thermal power plants were identified as the significant regional sources. Urban traffic and natural emission were identified as the local sources.Öğe Bottom slag-to-flue gas controls on S and Cl from co-combustion of textile dyeing sludge and waste biochar: Their interactions with temperature, atmosphere, and blend ratio(Elseiver, 2022) Huang, Hongyi; Liu, Jingyong; Evrendilek, Fatih; Zhang, Gang; Sun, Shuiyu; He, YaoS and Cl distribution patterns and their evolution pathways were quantified during the co-combustions of textile dyeing sludge (TDS) and waste biochar (BC). S in the flue gas rose from 10.60% at 700 degrees C to 45.09% at 1000 degrees C for the mono-combustion of TDS in the air atmosphere. At 1000 degrees C, S in the bottom slag and flue gas grew by 2.65% and fell by 2.11%, respectively, for the TDS mono-combustion in the 30%O2/70%CO2 atmosphere. The 40% BC addition increased the S retention in the bottom slag by 30.39% and decreased its release to the flue gas by 34.50% by changing the evolution of CaSO4 and enabling more K to fix S as K2SO4. The decomposition of inorganic Cl was the main source of the Cl-containing gases. The 20%O2/80%CO2 atmosphere (36.29%) and 40% BC addition (27.26%) had higher Cl in the bottom slag than did TDS mono-combusted at 1000 degrees C (25.60%) by inhibiting the decomposition of organic Cl. Our study provides insights into the co-combustion of TDS and BC and controls on S and Cl for a cleaner production. Future research remains to conducted to verify scale-up experiments.Öğe Comparison performances of hybrid sonocatalysis and sonophotocatalysis on the elimination of 2,4-dichlorophenoxyacetic acid in water: Mineralization and economic analysis(Hard, 2022) Dikmen, Emre; Doğdu, Gamze; Yalçuk, ArdaThis study compares the removal performances of sonocatalysis (SC) coupled with commercially available titanium dioxide ( TiO2, P25) and combined sonophotocatalysis (SPC) with H2O2 of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide in aqueous media in batch experiments. A SC process (US/TiO2) with 75 mg/L 2,4-D obtained 65.58 +/- 0.42% degradation, 7.84 +/- 1.3% mineralization, and 15.86 +/- 0.39% oxidation at a pH of 2, and a temperature of 35 +/- 1 degrees C under optimum conditions after 360 minutes, whereas 82.24 +/- 2.91% degradation, 44.50 +/- 0.11% mineralization, and 55.11 +/- 0.35% oxidation were obtained after 360 minutes with SPC (US/ UVA/TiO2-H2O2), with the addition of an optimum 250 mg/ L of H2O2. The synergistic index was calculated as 1.77 that indicated the positive effect of the combined system on degradation efficiency when compared with the individual processes. Total costs were obtained as 5072 USD/ kg for SC and 4135 USD/kg for SPC, showing the cost efficiency of the hybrid SPC process in comparison to the SC process. The obtained results confirmed that the hybrid SPC process was more effective than the SC process in degrading and mineralizing 2,4-D for removal. Operation time was shorter, energy consumption was lower, and operation cost was lower when compared to the SC process.Öğe Effects of structural changes in bile salt hydrolase enzyme on biocatalytic efficiency and activation energy at working pH and temperature conditions(Hrvatsko Drustvo Kemjijskih Inzenjera I Tehnologa, 2022) Ermurat, Yakup; Öztürk, Mehmet; Önal, Cansu; Kılıçsaymaz, ZekiyeMicrobial bile salt hydrolases (BSHs) catalyse the hydrolysis of glycine and taurine-linked bile salts in the small intestine of humans. Achieving the effects of structural changes in BSH molecules on biocatalytic efficiency (kcat/Km) and activation energy (Ea) is necessary to determine biocatalytic performances of the enzymes. Amino acids responsible for biocatalytic activity or substrate specificity in BSH molecules were modified to determine the effects of structural changes on kcat/Km values and Ea values of the bioconversion reactions. Purified wild type positive control enzyme (pCON2) and mutant recombinant target enzymes (F18L and Y24L) reacted with six conjugated pure bile salt substrates at working temperature and pH conditions. The results of the hydrolysis conversion analysis conducted at various pH conditions were used to estimate kcat/Km, and the assays conducted at various temperature conditions were used to approximate Ea of the biocatalytic reactions. The quantified kcat/ Km value was found remarkably highest with mutant recombinant enzymes (Y24L), while the efficiency value with wild type (pCON2) was determined as lowest, indicating that the structural modifications in BSH molecules showed higher values. The alterations with the mutant-type enzymes F18L and Y24L resulted in decreasing kcat/Km and increasing Ea estimations of the hydrolysis conversion reactions.Öğe Dynamic pyrolytic reaction mechanisms, pathways, and products of medical masks and infusion tubes(ELSEVIER, 2022) Xu, Weijie; Liu, Jingyong; Ding, Ziyi; Fu, Jiawei; Evrendilek, FatihGiven the COVID-19 epidemic, the quantity of hazardous medical wastes has risen unprecedentedly. This study char-acterized and verified the pyrolysis mechanisms and volatiles products of medical mask belts (MB), mask faces (MF), and infusion tubes (IT) via thermogravimetric, infrared spectroscopy, thermogravimetric-Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography/mass spectrometry analyses. Iso-conversional methods were employed to estimate activation energy, while the best-fit artificial neural network was adopted for the multi-objective optimization. MB and MF started their thermal weight losses at 375.8 degrees C and 414.7 degrees C, respectively, while IT started to degrade at 227.3 degrees C. The average activation energies were estimated at 171.77, 232.79, 105.14, and 205.76 kJ/mol for MB, MF, and the first and second IT stages, respectively. Nucleation growth for MF and MB and geometrical contraction for IT best described the pyrolysis behaviors. Their main gaseous products were classified, with a further proposal of their initial cracking mechanisms and secondary reaction pathways.Öğe An assessment of spatial distribution and atmospheric concentrations of ozone, nitrogen dioxide, sulfur dioxide, benzene, toluene, ethylbenzene, and xylenes: ozone formation potential and health risk estimation in Bolu city of Turkey(Springer Heidelberg, 2022) Dörter, Melike; Türk, Esra Mağat; Döğeroğlu, Tuncay; Üzmez, Özlem Özden; Gaga, Eftade Emine; Karakaş, Duran; Karakaş, Serpil YenisoyAtmospheric pollutants including ozone, nitrogen dioxide, sulfur dioxide, and BTEX (benzene, toluene, ethylbenzene, and xylenes) compounds were evaluated concerning their spatial distribution, temporal variation, and health risk factor. Bolu plateau where sampling was performed has a densely populated city center, semi-rural areas, and forested areas. Additionally, the ozone formation potentials of BTEXs were calculated, and toluene was found to be the most important compound in ground level ozone formation. The spatial distribution of BTEXs and nitrogen dioxide pollution maps showed that their concentrations were higher around the major roads and city center, while rural-forested areas were found to be rich in ozone. BTEXs and nitrogen dioxide were found to have higher atmospheric concentrations in winter. That was mostly related to the source strength and low mixing height during that season. The average toluene to benzene ratios demonstrated that there was a significant influence of traffic emissions in the region. Although there was no significant change in sulfur dioxide concentrations in the summer and winter seasons of 2017, the differences in the spatial distribution showed that seasonal sources such as domestic heating and intensive outdoor barbecue cooking were effective in the atmospheric presence of this pollutant. The lifetime cancer risk through inhalation of benzene was found to be comparable with the limit value (1 x 10(-6)) recommended by USEPA. On the other hand, hazard ratios for BTEXs were found at an acceptable level for different outdoor environments (villages, roadside, and city center) for both seasons.Öğe Converting and valorizing heavy metal-laden post-harvest hyperaccumulator (Pteris vittate L.) into biofuel via acid-pretreated pyrolysis and gasification(Elsevier Science SA, 2023) Huang, Shengzheng; Liu, Jingyong; Chen, Siqi; Wang, Jin; Chen, Zhibin; Evrendilek, FatihNot only should post-harvest hyperaccumulators rich in heavy metals (HMs) be properly disposed to avoid secondary HMs pollution, but also they should be valorized to enhance circular economy. This study aimed to characterize how As-hyperaccumulator (Pteris vittate L.) (PV) pretreated with HCl or H3PO4 affected its physi-cochemical, HMs, decomposition, and volatile characteristics. The HCl-pretreated PV retained its original main components, physical properties, and chemical structures but introduced Cl to carbon chain, induced O loss, increased C content, and removed most minerals, in particular, alkali/alkaline earth metals. The favorable py-rolysis and gasification behaviors of PV were maintained via the HCl-pretreated PV, with the raised and nar-rowed temperature range of mass loss but with the increased energy demand for the decomposition. Compared with PV (276.74 kJ/mol), 5% HCl-pretreated PV reduced activation energy of its pyrolysis (260.62 kJ/mol). The H3PO4 pretreatment destroyed carbon chain, loaded phosphorus oxygen group, and removed more organics and minerals in PV than did the HCl-pretreated PV. This in turn allowed for an earlier start and finish of devolati-lization stage, an easier breaking of potential energy barrier, and improvement of reaction favorability. Unlike the two atmospheres, the acid pretreatments changed the temperature dependency of volatile products during the main reaction-temperature range. The volatile products which released from the pyrolysis and gasification at the temperature of maximum mass loss peak or 350 degrees C were collected. HCl-pretreated PV reduced the formation of ring-opening products, while H3PO4-pretreated PV emitted more aromatic compounds and selectively generated ketone, such as levoglucanone. More HMs were dissolved with the increased acid concentration, with HMs in HCl-pretreated PV being at a higher leaching concentration than those in the other treatments. H3PO4- pretreated PV retained As, Cd, and Pb at a low leachable rate. The best joint optimization was achieved with the combined settings of 5% HCl-pretreated PV or 10% H3PO4-pretreated PV at 10 degrees C/min in the N2 atmosphere. Overall, findings provide new insights into how to best manage and valorize post-harvest and HM-laden hyperaccumulators.Öğe An eco-friendly hybrid sonophotocatalytic approach to optimize carpet washing wastewater treatment(DESALINATION PUBL, 2022) Doğdu, GamzeThe fundamental objective of this work is to examine the efficiency of the hybrid advanced treatment process for removal of residual organic pollutants in carpet washing wastewater at various reaction conditions. For this goal, Taguchi method was adopted to optimize the critical factors viz. catalyst type (TiO2 and ZnO), catalyst concentration (0.5-2.5 g/L), pH (2-10), H2O2 concentration (0-10 mM), and operation time (30-180 min). These experimental factors were handled in mixed levels (2(1) x 3(4)), and operation parameters were optimized by the application of L 18 tests. The analysis of variance results showed that catalyst type, H2O2 concentration, and pH had the highest effects on the elimination of chemical oxygen demand (COD) and color. COD and color removal efficiencies were determined as 53% and 99%, which are close to the predicted values of 49% and 95%, respectively, according to the confirmation test carried out under optimal parameters. Thus, considering the cost of energy consumed and acceptably high COD and color removal level, the sonophotocatalysis process combining ultrasound, ultraviolet, hydrogen peroxide, and catalyst (TiO2 and ZnO) could achieve great performance for the reduction of pollution load in wastewater by the fast and eco-friendly removal of organic pollutants from carpet washing effluents.
