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    Development and validation of climate change awareness scale for high school students
    (Springer, 2023) Gonen, Cagdas; Deveci, Ece Ummu; Aydede, Meryem Nur
    The topic of climate change has begun to be referred to as the global climate change crisis. Despite the precautions taken through international accords, the main solution to climate change will be an increase in individual knowledge and awareness, as well as change in their behavior as a result. A valid and reliable climate change awareness (CCA) scale for high school students was developed in this study. As a scale development strategy, an inductive scale development approach was used. The study enrolled a total of 454 high school students. In this study, both exploratory and confirmatory factor analyses were used to provide validity. In this way, the CCA scale was developed and validated using two different randomly separated samples. Sample 1 (274 high school students) was assigned to the exploratory factor analysis group, while sample 2 (180 high school students) was utilized to confirm the factor structures via confirmative factor analysis. Confirmatory factor analysis was used to check model-data coherence and test assumptions about variable relationships. As a result of the study, a valid and reliable Likert-type scale for assessing high school students' climate change awareness was developed. The scale consists of 17 items and a Cronbach alpha value of 0.88. CFI (0.93), NFI (0.82), RFI (0.88) and GFI (0.90) RMSEA (0.045) have proven to be acceptable fit indexes between the model and the data for the research model. Thus, the fit indexes produced as a result of the CFA indicated that the model had good fit.
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    Evaluation of biomass pretreatment to optimize process factors for different organic acids via Box-Behnken RSM method
    (Springer, 2021) Gonen, Cagdas; Deveci, Ece Ummu; Akter Onal, Nagehan
    Biomass, as renewable energy source, is of importance to investigate to extend the conversion yield by microorganism. Because of lignocellulosic structure, biomass must be pretreated with a process, frequently inorganic acid has to be used with a problem of hazardous byproducts. Organic acid pretreatment is an efficient alternative to be investigated. Sugar beet pulp, as an agro-industrial residue of microorganism, can be utilized by pretreatment, which is usually a costly process. Pretreatment with organic acids creates a great opportunity to convert the process into more economic and effective. Moreover, pressure conditions significantly increase the yield of biodegradable sugar content. In this study, different organic acids of maleic, fumaric, oxalic, and acetic acid pretreatment was investigated to pretreatment of sugar beet pulp, which came vast amount from factories, under pressure and non-pressure conditions via Box-Behnken method to estimate optimum point of acid ratio (1, 3, 5%), time (10, 27.5, 45 min), and solid ratio factors (3, 6.5, 10%) for highest degradation. Results were also evaluated economically. As a result of the experiments, it was observed that acetic acid gave the best result with 409.16 g/L total sugar concentration than the other organic acids. The highest TS concentration of maleic, oxalic, and fumaric acid were 97.26, 97.85, and 91.37 g/L, respectively, under pressure. According to economical evaluation, owing to lower market price and highest TS formation yield, pretreatment cost of acetic acid pretreatment was found averagely 1.51 $/gTS under pressure conditions.
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    Impact of COVID-19 restrictive precautions on air quality: case of Zonguldak, Turkey
    (Inderscience Enterprises Ltd, 2022) Koklu, Rabia; Turkmen, Burcin Atilgan; Deveci, Ece Ummu; Gonen, Cagdas
    The purpose of this study was to investigate and assess how restrictive COVID-19 precautions affect air quality in Zonguldak, as well as to determine the relationship between air quality and meteorological variables under these conditions. Daily PM2.5, PM10, SO2, and NOx concentrations and meteorological data, from 1 March to 31 May 2018, 2019, and 2020 were collected for this research. During the 2020 restrictive COVID-19 precautions, it was determined that concentrations of air pollutants were different and low based on the 95% confidence interval by using paired t-test samples. Meteorological variables were found to be similar to previous years, and the correlation between them and air pollutants was found to be significant (P < 0.01) but low according to Pearson correlations. As a result, meteorological variables were determined to have no direct effect on the low concentrations of air quality emissions during the 2020 pandemic. The overall findings revealed that anthropogenic impact has a negative impact on air quality and the air quality had improved during the COVID pandemic. Furthermore, the restriction on the region's coalmines during the COVID-19 pandemic has significant impact on the improvement of air quality.
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    Investigation of the bacterial modified waste PET aggregate VIA Bacillus safensis to enhance the strength properties of mortars
    (Elsevier Sci Ltd, 2021) Akcaozoglu, Semiha; Adiguzel, Ali Osman; Akcaozoglu, Kubilay; Deveci, Ece Ummu; Gonen, Cagdas
    Polyethylene terephthalates (PET), which are highly resistant to degradation under natural environmental conditions due to their inert, hydrophobic and high molecular weights, are collected in landfills or dispersed as waste. Considering the increasing use of PET, the interest in multidisciplinary studies aimed to obtaining high value added products from PET wastes has increased. In this study, the potential of using waste plastics made of Polyethylene terephthalate (PET) treated with bacteria as an aggregate in the production of mortar was investigated. First, the bacterial strains, which secreted esterase or cutinase, were screened for their ability to attach to hydrophobic surfaces and biofilm formation. TH401, which showed potential for the modification of the PET aggregates, was identified as Bacillus safensis. To enhance the compatibility of the PET, the waste PET aggregates were treated with submerged fermentation via B. safensis TH401. The FTIR analyses conducted after the treatment showed that the chemical structure of the PET had been modified. Mortar samples were prepared by using the modified PET aggregates. The compressive and flexural tensile strength values of the samples were measured on days 7, 28 and 56. The compressive strength values of the bacteria modified samples were 4.87%, 7.51% and 13.13% higher than the non-bacterial samples at 22 degrees C, 30 degrees C and 50 degrees C, respectively. The increase in curing temperatures had a positive effect on compressive and flexural tensile strength values. The highest strength values were obtained in the samples cured at 50 degrees C. In the EDX spot of the mixtures, major peaks of C, O, Ca were detected indicating the presence of CaCO3 and bacteria. Stratification on the PET surface as a result of bacterial modification was clearly observed in the SEM images. The test results showed that bacterial modification contributed to the increase in the strength of the waste PET aggregate concrete. It can be said that mortars produced with bacteria modified PET aggregates can be used as an economical and environmentally friendly material alternative in the construction industry. (C) 2020 Elsevier Ltd. All rights reserved.
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    Optimization of sugar beet pulp pre-treatment with weak and strong acid under pressure and non-pressure conditions via RSM
    (Springer Heidelberg, 2023) Gonen, Cagdas; Onal, Nagehan Akter; Deveci, Ece Ummu
    Biofuels, derived from sustainable biomass feedstock, are promising alternatives for fossil derivative fuels to mitigate climate change and air pollution. The molecular structure of lignocellulosic biomass, which creates the limitation of utilization by microorganisms, can be degraded to fermentable sugar via a pre-treatment process. In this study, citric acid as a weak acid and sulfuric acid as a strong acid were used for the pre-treatment of sugar beet pulp under pressure and non-pressure conditions. Fermentable sugar amount was determined for total sugar and reduced sugar formation. Acid ratio, solid ratio and reaction time variables were optimized for the highest fermentable sugar concentration via Box-Behnken statistical methods. Finally, pressure is significantly increasing the strong acid effect, where the total sugar can reach up to 33 g/L at 4% acid ratio, 27.5-min reaction time, and 5% solid ratio. A 27.5-min reaction time gives 11 g/L total sugar concentration under pressure conditions at 5% citric acid ratio. The highest reduced sugar concentration is 1170 mg/L for sulfuric acid under pressure with only 3% solid ratio. SEM-EDX and FT-IR analysis show reliable degradation of molecular structure. SEM analysis showed that under the same conditions at 100 degrees C and 1 atm, sulfuric acid produced a much more intense deformation than citric acid, with more fragmentation occurring on the surface parallel to the TS. In addition, protein analysis obtained using Aspergillus niger in microbial cultivation experiments supports that pre-treatment products may be suitable for biofuel production and microbial use. The highest protein value obtained by sulfuric acid pre-treatment is 120 mg/L. Pre-treatment is necessary for the development of microbial activity in the production of biofuels from agricultural wastes. The total protein content is an important parameter in determining total enzyme production in monitoring microbial growth.
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    Pre-treatment optimization of barley straw as agro-industrial waste via alkaline peroxide and ultrasound for soluble sugar production and degradation
    (Springer Heidelberg, 2021) Deveci, Ece Ummu; Gonen, Cagdas; Akarsu, Ceyhun
    Pre-treatment of biomass is of great importance to maximize the recovery of fermentable sugars and minimize the amount of enzyme inhibitors formed. There are several processes that can be applied for pre-treatment of agricultural industrial waste such as chemical, physical, physico-chemical, biological, and combined pre-treatments. Alkaline hydrogen peroxide (AHP) and ultrasonication are two of this pre-treatment process. The aim of this study was to investigate the pre-treatment performance of barley straw biomass using AHP and combined ultrasonic-hydrogen peroxide process via Box-Behnken design as a response surface methodology (RSM). The factors of time (30-120 min), particle size (0.2-1 mm), peroxide dosage (1-5%), and temperature (50-100 degrees C) are investigated for optimum operating conditions. For ultrasonication process, factors are time (5-30 min), particle size (0.2-1.0 mm) and US power (20-100 Kj/kgDM). During AHP pre-treatment, maximum total and reduced sugar concentration was found as 14 g/L and 660 mg/L, respectively, at maximum level of time and minimum level of dosage factors which are 120 min and 1%, respectively. Maximum total and reduced sugar concentration can be reached nearly 7.6 g/L and 810 mg/L, respectively, at minimum level of time which is 5 min and almost minimum level of chemical dosage in ultrasound-hydrogen peroxide process, respectively.
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    Treatment of slaughterhouse wastewater by electrocoagulation and electroflotation as a combined process: process optimization through response surface methodology
    (Springer Heidelberg, 2021) Akarsu, Ceyhun; Deveci, Ece Ummu; Gonen, Cagdas; Madenli, Ozgecan
    The contamination of water with organic compounds has become an increasing concern in today's world. The cost-effective and sustainable treatment of industrial wastewaters is a major challenge. Advanced treatment techniques such as electrocoagulation-electroflotation offer economic and reliable solutions for the treatment of industrial wastewater. In this study, the electrocoagulation-electroflotation method was investigated for the simultaneous removal of chemical oxygen demand, total phosphorus, total Kjeldahl nitrogen, and color via response surface methodology. Factors such as electrode combination (Fe and Al), current density (10-20 mA/cm(2)), pH (3.0-9.0), and electrode distance (1-3 cm) were investigated in the treatment of wastewater to obtain maximum treatment efficiency. It was determined that chemical oxygen demand, total Kjeldahl nitrogen, total phosphorus, and color removal reached up to 94.0%, 77.5%, 97.0%, and 99.0%, respectively. Treatment costs were found as $0.71 with the Al-Fe electrode combination.