Optimum air feed locations on medical waste incineration rotary kiln by computational fluid dynamics (CFD)

Twenty-four tons of medical waste is combusted every day in Istanbul. The plant is operated by ISTAÇ AŞ and combustor type is rotary kiln. The air was being fed manually along with the waste being introduced to the kiln. This case caused some problems regarding the combustion efficiency. The administration staff decided to open holes to supply air to the combustor. In this study, CFD was utilized in order to determine the optimum places for air inlets. Flow geometry of the air was prepared and then meshed for calculations. k-ε turbulence model was utilized in the calculations. Four air inlet pipes were placed on the edges of the circular inlet area. Different locations were tested. When the air was fed from the top, waste could not completely contact with the air. Additionally, different inlet angles were tested from zero degrees to thirty degrees. The degree of the inlet did not much change the combustion characteristics inside the kiln. Piping holes were burrowed from the bottom at zero degree angle

Determination of Biological Treatability Processes of Textile Wastewater and Implementation of a Fuzzy Logic Model

This study investigated the biological treatability of textile wastewater. For this purpose, a membrane bioreactor (MBR) was utilized for biological treatment after the ozonation process. Due to the refractory organic contents of textile wastewater that has a low biodegradability capacity, ozonation was implemented as an advanced oxidation process prior to the MBR system to increase the biodegradability of the wastewater. Textile wastewater, oxidized by ozonation, was fed to the MBR at different hydraulic retention times (HRT). During the process, color, chemical oxygen demand (COD), and biochemical oxygen demand (BOD) removal efficiencies were monitored for 24-hour, 12-hour, 6-hour, and 3-hour retention times. Under these conditions, 94% color, 65% COD, and 55% BOD removal efficiencies were obtained in the MBR system. The experimental outputs were modeled with multiple linear regressions (MLR) and fuzzy logic. MLR results suggested that color removal is more related to COD removal relative to BOD removal. A surface map of this issue was prepared with a fuzzy logic model. Furthermore, fuzzy logic was employed to the whole modeling of the biological system treatment. Determination coefficients for COD, BOD, and color removal efficiencies were 0.96, 0.97, and 0.92, respectively

Compositional Variation of PCBs, PAHs, and OCPs at Gas Phase and Size Segregated Particle Phase during Dust Incursion from the Saharan Desert in the Northwestern Anatolian Peninsula

A dust incursion occurred in Istanbul on 1 February 2015 from the Saharan Desert. During this episode, 938 μg·m−3 of TSP concentration was observed. TSP concentration was 64 μg·m−3 and 78 μg·m−3 on the following two days. Particles of 3 μm were dominant during the episode; however, particles < 0.49 μm were dominant after the episode. The averages of total (gas + particle) PCB, PAH, and OCP concentrations were 279 pg·m−3, 175 ng·m−3, and 589 pg·m−3, respectively. Tri-CBs were dominant in most of the samples. Flt and Phe had the highest contribution to PAH species. β-HCH and heptachlor had the highest share in terms of OCPs. Particle phase PCBs exhibited monomodal size distribution, whereas OCPs had bimodal size distribution. PAHs exhibited either monomodal or bimodal size distribution on different days. The mass median diameter of PAHs did not change significantly during different atmospheric conditions due to their local sources. Gas/particle partitioning of each pollutant was evaluated by plotting their subcooled vapor pressure against the partitioning coefficient. From 1 to 3 February, the slope of the regression line shifted close to −1, indicating that the least favorable conditions were present during dust incursion for an equilibrium state

İstanbul’da kış hava şartlarında atmosferik organoklorlu pestisit seviyeleri ve gaz/partikül dağılımları

In this study, gas and particle phase ambient organochlorine pesticide (OCP) levels were investigated atan urban site in Istanbul. Samples were collected by a high-volume sampler for fourteen days in winter. Individual OCP concentrations were between13 and 593 pg.m-3 for particle phase and 14 and 1,748 pg.m-3 for gaseous phase. The sums of the average concentration of each OCP in gaseous and particle phases were 3,219 and 2,746 pg.m-3 , respectively. δ-HCH had the highest individual concentration. The abundance of DDTs followed the order 4.4'-DDT > 4.4'-DDD > 4.4'-DDE.The Σ(gas+particle)OCP concentrations ranged between 1,845 and 10,196 pg.m-3 . On the days when high concentrations were observed, the trajectories of air masses were investigated by the HYSPLIT model. logKp versus logPL 0 model was applied in order to determine the fate of gas/particle partitioning. The average slope of the regression line was -0.35, whereas the intercept was -2.89.Bu çalışmada, İstanbul'un kentsel bir yerleşim bölgesinde gaz ve partikül fazında ortam havası organoklorlu pestisit (OCP) seviyeleri araştırılmıştır. Örnekler, kış aylarında on dört gün boyunca yüksek hacimli örnekleyici kullanılarak toplanmıştır. Bireysel OCP konsantrasyonları partikül fazı için 13 ila 593 pg.m-3 ve gaz fazı için 14 ila 1.748 pg.m-3 arasında değişmiştir. Gaz ve partikül fazlarındaki her OCP'nin ortalama konsantrasyon toplamı sırasıyla 3,219 ve 2,746 pg.m-3 olarak tespit edilmiştir.δ –HCH’nin en yüksek bireysel konsantrasyona sahip olduğu gözlemlenmiştir. DDT'lerin bulunma oranları şu sırada olduğu görülmüştür: 4.4'-DDT> 4.4'-DDD> 4.4'-DDE. Σ (gaz + partikül) OCP konsantrasyonları 1,845 ila 10,196 pg.m-3 arasında değişim göstermiştir. Yüksek konsantrasyonların gözlemlendiği günlerde hava kütlelerinin yörüngeleri HYSPLIT modeli ile incelenmiştir.Gaz/partiküldağılımınınakıbetini belirlemek üzere logKp-logPL 0 modeli uygulanmıştır.Regresyon eğrisinin ortalama eğimi -0.35 iken, kesim noktası - 2.89 olarak bulunmuştur

Life cycle assessment and greenhouse gas emission evaluation from Aksaray solid waste disposal facility

WOS: 000435421100006Life cycle assessment (LCA) is a popular tool used to assess the environmental performance of municipal solid waste (MSW) management systems. In this study, LCA method was used to determine the best municipal solid waste management strategy for Aksaray city, Turkey. Four different scenarios were developed as an alternative to the existing waste management system and evaluated for the best environmental solution. The scenario with 75% landfilling-25% composting provided the best results in terms of human health and environmental impact. Current emissions from the present MSW facility were estimated for methane and carbon dioxide emissions. Annual emissions in 2017 were 8674 and 3161 t year(-1) for CO2 and CH4, respectively. The estimated ground-level concentrations of these emissions were 30 and 50 mu g m(-3) for CO2 and CH4, respectively. Both modeled CO2 and CH4 concentrations were expressed as CO2(eq). The total radiative forcing was calculated as 0.021 W m(-2)

Investigation of EU environmental policies from the past to the future in the LCA perspective

*Çetinkaya, Afşin Yusuf ( Aksaray, Yazar )event Bilgili, Afşin Yusuf Çetinkaya, Sadullah Levent Kuzu Investigation of EU Environmental Policies from the Past to the Future in the LCA Perspective Introduction According to the First Law of Thermodynamics, energy can be transformed from one form to another but can be neither created nor destroyed. This law tells us that there is a great balance of energy in nature. This energy balance appears not only in engineering but also in all environmental, social and economic cycles. Humanity, like all other living things in nature, has lived in harmony with environmental cycles in nature for millennia, and there is no waste in any environmental cycle. The energy entering the system does not disappear, changes shape and emerges as another type of energy. The waste products generated during this change process are used as input to another system and a new cycle begins. After the 18th century, when industrial production began, man-made artificial products started to produce outputs that could not be used as energy inputs in any system by disrupting this cycle, and nature was introduced to a concept that did not belong to it: Waste. Waste generation is a part of industrial production and is a process that has the potential to cause great environmental damage if not avoided

Dispersion modelling of volatile organic compound emissions from Ataköy wastewater treatment plant in İstanbul

WOS: 000423283800005In this study, emissions released from a wastewater treatment plant in Istanbul, were estimated utilising air quality dispersion model. The treatment plant is located to the west of a residential site. So, the emissions have potential to affect the living people in the residential area. Emission factor and wastewater treatment capacity were used to calculate the emission rate. Turkish State Meteorological Service data were used in order to produce meteorological input to the model. Elevation data were gathered from Shuttle Radar Topography Mission data. AERMOD was executed with those input data. Hourly maximum, daily maximum, monthly maximum, and annual average concentration distribution plots were generated. The maximum values were 471, 171, and 42 mu g/m(3), on hourly, daily, and monthly basis, respectively. The maximum concentration observed on the annual average map was 29 mu g/m(3)

Climatological evaluation in a Central Anatolian city and indirect effects of climatological variation on air quality

Climate is defined as the statistics of weather over a long period of time. Climate has a dynamic structure, and climate change is caused either by natural or anthropogenic effects. Meteorological parameters are routinely recorded by national weather stations. In this study, climate variability was analyzed in a mid-populated city in the middle of the Anatolian Peninsula. Humidity, temperature, precipitation, open surface evaporation, and solar radiation records over 57-year period from 1960 to 2016 were considered. The increase in temperature and solar radiation was obvious. The increase rates were 0.05 °C and 0.62 W/m2 for temperature and solar radiation, respectively. Relative humidity showed a declining trend from 64 to 53%. This study also aimed to evaluate the climate change of planetary boundary layer development, which influences air quality level. AERMET, which is the AERMOD meteorological preprocessor was exploited in order to simulate the planetary boundary layer height, and twice daily upper air soundings, wind speed, wind direction, ambient temperature, and cloud cover have been used as minimum required parameters. The complete meteorological data available were between 2006 and 2016; for that reason, the boundary layer was calculated for 11 years. The determined average boundary layer height was 1018 m in 2006 and was reduced to 889 m in 2016. © 2019, Springer Nature B.V.The authors greatly acknowledge Turkish State Meteorological Service for providing the extensive data set of Aksaray weather records