The impacts of Covid-19 on the household behavior and household waste in Turkey

Due to the COVID-19, many radical changes have occurred in our daily life. The main purpose of this study is to examine the impacts of COVID-19 pandemic on the household behavior and waste changes in the largest city of Turkey, Istanbul. Research data were collected through an online survey, from 946 participants and frequency and logistic regression analyses were conducted. As a result of the frequency analyses of the data, it was revealed that mask, glove, disposable bag usage, cooking at home, online shopping, cargo arrival, dishwasher and washing machine usage increased; on the contrary, ordering food from outside decreased among the participants. In line with these behavioral changes, we found that medical, food, disposable bag and plastic wastes generated by the sampled households increased, as well. Illuminating the results of frequency distributions, we conducted logistic regression analyses to explain the changes in each household behavior as well as waste disposal based on income and size of households during this pandemic period. The empirical findings of the present study highlight the importance of developing special management strategies for medical, food and plastic wastes and for households with different socio-economic backgrounds by local and central authorities in order to reduce the negative environmental impacts of COVID-19

Effects of persulfate, peroxide activated persulfate and permanganate oxidation on treatability and biodegradability of leachate nanofiltration concentrate

The effects of persulfate (PS), peroxide activated persulfate (P-PS) and permanganate (PM) oxidation processes on leachate nanofiltration (NF) concentrate treatment have been activated. Additionally, COD fractions were determined and compared before and after each oxidation process. The total COD removal efficiencies by the oxidation processes using PS, P-PS, and PM as the oxidants were determined to be 24.5%, 32.9%, and 39.5%, respectively. The biodegradable COD fraction increased from 6.37% to 9.25%, 11.51%, and 13.64% after the PS, P-PS, and PM oxidation processes, respectively. About 25%, 34%, and 46% removal efficiencies of the inert COD content of the concentrate were obtained after the PS, P-PS and PM oxidation processes, and the soluble COD fraction increased from 71.1% to 87.2%, 89.0% and 84.6% by the PS, P-PS and PM oxidation processes, respectively. Although the highest removal efficiencies were achieved by PM oxidation with the lowest operational cost, all of the processes may be suggested as efficient methods for conversion of insoluble COD into the soluble COD fraction and for inert COD removal. The results of the study showed that the PS, P-PS, and PM oxidation processes may be effectively utilized as post-treatment techniques for leachate NF concentrate treatment

Assessment of environmental impact of FOOD waste in Turkey

Food waste is a multifaceted problem that has negative impacts on the environment. Life cycle assessment (LCA) is a tool that shows these environmental impacts as quantifiable and is able to interpret the results with an integrated approach. In this study, LCA was used to analyze food waste in Turkey from a bottom up processing perspective. In order to assess the environmental impact of food waste on climatic, water, and energy resources, we calculated the embedded carbon, water, and energy footprints throughout the food supply chain in Turkey. Avoidable food waste was calculated as 16 Mt in Turkey in the year 2016. It is estimated that food waste in Turkey embodied 23.7 Mt of CO2-eq, 6.2 x 10(9) m(3) of water and 13.5 x 10(4) TJ of energy. The results obtained by this research could be used to assess the linkage between food waste and the carrying capacity of resources. (C) 2019 Elsevier Ltd. All rights reserved

Kaolinitin kıvam limitleri üzerine inorganik tuz çözeltilerinin etkileri

This study presents the effect of different inorganic salt solutions (KCl, BaCl2, MgCl2, KNO3, Na2SO4 and MgSO4) at different concentrations on geotechnical properties (Atterberg Limits) of kaolinite material which can be used as impermeable bottom liner in barrier systems. Since the use of distilled water or tap water is far from being representative of the in-situ conditions in landfills, salt solutions were used to investigate the leachate effect on liner materials. Additionally, the mineralogical characterization of kaolinite was studied. Atterberg limits, specifically the liquid limit (LL) and plastic limit (PL) that were used for classifying the clayey soil samples according to the Unified Soil Classification System were determined whereas mineralogical studies performed included XRD, BET and FT-IR analyses. Results indicated that all salt solutions have a considerable effect on the consistency limits of kaolinite. The liquid limit values of kaolinite decreased with increasing chemical concentration whereas plastic limit values increased. It is observed that the effects of the divalent and trivalent cations on kaolinite were more apparent than those of monovalent cations. As a result chemical solutions decrease liquid limit values of high plasticity kaolinite materials, tend to reduce the thickness of the DDL and flocculate the kaolinite particles, resulting in reduction of swelling and increasing of hydraulic conductivity.Bu çalışma, farklı konsantrasyonlardaki inorganik tuzların (KCl, BaCl2, MgCl2, KNO3, Na2SO4 ve MgSO4) bariyer sistemlerde geçirimsizlik alt tabaka dolgu malzemesi olarak kullanılan kaolinitin geoteknik özellikleri (Atterberg Limitleri) üzerine etkileri ortaya koymaktadır. Distile su veya çeşme suyu kullanımı, depo sahası koşullarını temsil edici olmadığından, dolgu malzemeleri üzerine sızıntı suyu etkilerini araştırmak için tuz çözeltileri kullanılmıştır. Ayrıca, kaolinit malzemesinin minerolojik karakterizasyonu incelenmiştir. Killi zemin numunelerinin, Birleşik Zemin Sınıflandırma Sistemi’ne göre Atterberg Limtleri; likit limit (LL) ve plastik limit (PL) değerleri belirlenmiş ve minerolojik çalışmalar için XRD, BET ve FT-IR analizleri gerçekleştirilmiştir. Elde edilen sonuçlar, tüm tuz çözeltilerinin kaolinin kıvam limitleri üzerinde önemli bir etkisi olduğunu göstermiştir. Kimyasal konsantrasyon artışı, kaolinitin likit limit değerlerini düşürürken plastik limit değerlerini arttırmıştır. 2 ve 3 değerlikli katyonların kaolin üzerine etkileri, tek değerlikli katyonlara göre açıkça görülmüştür. Sonuç olarak, kaolinit malzemesi hidrolik iletkenliği artar ve şişme eğilimi azalırken, DDL tabakası incelme ve kaolinit partikülleri floküle olma eğiliminde iken, kimyasal çözeltiler yüksek plastisiteye sahip kaolinit malzemesinin likit limit değerlerlerini düşürmektedir

The carbon footprint of a university campus: Case study of Yildiz Technical University, Davutpaşa Campus, Turkey.

In this study, the carbon footprint of Yildiz Technical University (YTU), Davutpaşa Campus was calculated to draw attention to the sustainable use of resources, what needs to be done against global climate change, and to reveal the responsibilities of universities in this regard and the importance of their contributions. This study was carried out to emphasize the need for higher education institutions to lead in reducing the carbon footprint in every living area in our country. IPCC and DEFRA methods were used to calculate the carbon footprint. The emission values obtained for 2019 and 2020 were 15244.4 and 7213.3 t of CO2, respectively. The largest component of emissions is electricity consumption, followed by transportation. The obtained values are similar to the results of the studies conducted on other university campuses. The reason for the low emission value in 2020 is the application of the online education system due to the pandemic. The precautions to be taken to reduce the carbon footprint are stated and suggestions are made. YTU, which has already adopted a new environmental policy, is rapidly advancing towards becoming a sustainable campus. In line with the sustainable campus vision, the carbon footprint is expected to decrease significantly

Norfloxacin removal by ultraviolet-activated sodium percarbonate and sodium hypochlorite: process optimization and anion effect

The efficiency of UV-activated sodium percarbonate (SPC) and sodium hypochlorite (SHC) in Norfloxacin (Norf) removal from an aqueous solution was assessed. Control experiments were conducted and the synergistic effect of the UV-SHC and UV-SPC processes were 0.61 and 2.89, respectively. According to the first-order reaction rate constants, the process rates were ranked as UV-SPC > SPC > UV and UV-SHC > SHC > UV. Central composite design was applied to determine the optimum operating conditions for maximum Norf removal. Under optimum conditions (UV-SPC: 1 mg/L initial Norf, 4 mM SPC, pH 3, 50 min; UV-SHC: 1 mg/L initial Norf, 1 mM SHC, pH 7, 8 min), the removal yields for the UV-SPC and UV-SHC were 71.8 and 72.1%, respectively. HCO3−, Cl−, NO3−, and SO42− negatively affected both processes. UV-SPC and UV-SHC processes were effective for Norf removal from aqueous solution. Similar removal efficiencies were obtained with both processes; however, this removal efficiency was achieved in a much shorter time and more economically with the UV-SHC process. HIGHLIGHTS The process rates in the UV-SPC and UV-SHC processes were higher than in single processes.; Norfloxacin removal by the UV-SPC and UV-SHC was 71.8 and 72.1%, respectively.; HCO3−, Cl−, NO3−, and SO42− negatively affected both processes.; UV-SHC is more energy efficient.

Removal of COD, phenol, and colour from olive mill wastewater by iron-activated persulphate process: multivariate optimisation approach

In this study, the treatability of olive mill wastewater by iron-activated persulphate (PS) oxidation was investigated. Central Composite Design (CCD) was applied to optimise the process parameters and establish a mathematical model for total phenol, chemical oxygen demand (COD), and colour removal from olive mill wastewater. The effect of process variables (PS dose, Fe2+ dose, initial pH, and reaction time) on pollutant removal efficiency was evaluated. The correlation coefficients of the quadratic polynomial equations were high for COD, total phenol, and colour removal by PS oxidation, and the model was found to be applicable. Optimum conditions determined by the developed model for maximum COD removal were pH 5, PS dose 206.7 mM, Fe2+ dose 70 mM, and reaction time 95 min. The COD, total phenol, and colour removal efficiencies estimated by the applied model were 46.74%, 94.62%, and 96.04%, respectively. The removal efficiencies obtained under optimum conditions as a result of the validation experiments were 45.5%, 93.8%, and 95.5% for COD, total phenol, and colour removal, respectively. The results of the study showed that PS oxidation in which Fe2+ is used as an activator is a suitable alternative for olive mill wastewater treatment

Removal of 4-nitrophenol from aqueous solution by natural low-cost adsorbents

7-25Use of adsorption isotherms, kinetics and thermodynamics for the removal of 4-nitrophenol (4-NP) from aqueous solutions by zeolite and bentonite has been investigated in a lab-scale batch study. Various parameters, such as adsorbent dosage, initial concentration of 4-NP, pH, operating temperature, and agitation time have been optimised for the maximum removal of 4-NP. With the optimized conditions (180 rpm agitation rate, 240 min agitation time, 7 pH, 298 K, 100 mg/L initial adsorbate concentration, and 5 g/L & 20 g/L for zeolite & bentonite dosages respectively), the removal percentages of 4-NP for natural zeolite and bentonite are found to be 51% and 68% respectively. The adsorption mechanisms and characteristic parameters for the present process are analyzed by four two-parameter (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich), five three-parameter (Redlich–Peterson, Toth, Sips, Radke-Prausnitz and Khan) isotherm models, and six kinetic models (Lagergren’s pseudo-first order, Ho and McKay’s pseudo-second order, Elovich, intraparticle diffusion, Bangham and modified Freundlich) using the non-linear regression methodology. Among the two-parameter isotherms, the experimental data yield excellent fits with Langmuir and Freundlich isotherm equations for both adsorbents. Three-parameter isotherms show higher determination coefficients (R2 > 0.999) and lower residual and standard errors than two-parameter isotherms. Of the three-parameter isotherms, Toth and Khan isotherms are the best to describe the experimental data of the 4-NP-zeolite system. Results of the kinetic studies show that the best-fitted kinetic models are the modified Freundlich, the Elovich and the Ho and McKay’s pseudo-second order for both 4-NP-zeolite and 4-NP-bentonite systems. The results also indicate that three-parameter isotherms have no significant correlations for the 4-NP-bentonite system. Adsorption thermodynamics of 4-NP [equilibrium constant, standard free energy changes, standard enthalpy and entropy changes] on zeolite and bentonite are also studied at various temperatures of 298, 318 and 338 K. The values of enthalpy changes and entropy changes are found to be –4.43 and –7.77 kJ/mol, and 3.43 and −9.76 kJ/mol.K for zeolite and bentonite respectively. The thermodynamic analysis indicates that the present adsorption systems are found to be exothermic, and the adsorption of 4-NP on zeolite and bentonite is spontaneous and physical in nature. Findings of this study clearly show that these materials could be used as efficient adsorbents for the removal of 4-NP from aqueous solutions