Istanbul Technical University

About: Istanbul Technical University is a education organization based out in Istanbul, Turkey. It is known for research contribution in the topics: Fuzzy logic & Large Hadron Collider. The organization has 12889 authors who have published 25081 publications receiving 518242 citations. The organization is also known as: İstanbul Teknik Üniversitesi & Technical University of Istanbul.

Photo-Fenton-like and photo-fenton-like oxidation of Procaine Penicillin G formulation effluent

Abstract: In the present study, the degradation of Procaine Penicillin G (PPG) formulation effluent by Fenton-like (Fe3+/H2O2) and UV-A light assisted Fenton-like (Fe3+/H2O2/UV-A) processes have been investigated at pH = 3. The effects of different process variables such as the initial Fe3+and H2O2 concentrations, reaction time and UV-A light on PPG formulation effluent degradation rates have been evaluated. Chemical oxygen demand (COD), 5-day biochemical oxygen demand (BOD5), total organic carbon (TOC) and acute toxicity towards the water flea Daphnia magna were selected as the environmental sum parameters to follow the performance of Fenton-like and photo-Fenton-like advanced oxidation processes on the PPG (Procaine Penicillin G) formulation effluent (CODo=600 mg/l; BOD5=53 mg/l; TOCo=450 mg/l). At optimum reaction conditions (i.e. [Fe3+]=1.5 mM and [H2O2]=25 mM, pH = 3), 56% COD and 42% TOC removal where achieved by the photo-Fenton-like process after 30 min treatment time, whereas the removal efficiencies of the dark Fenton-like process were limited to 44% COD and 35% TOC for the same treatment period. The superiority of the UV-A light-assisted Fenton-like process over the dark Fenton-like reaction was more evident in terms of their effect on biodegradability improvement; the BOD5/COD ratio increased from 0.10 to 0.45 and 0.10 to only 0.24 after application of the photo-Fenton-like and Fenton-like processes, respectively. Based on the results of acute toxicity tests it could be inferred that the photo-Fenton-like process is a suitable method for complete detoxification and partial oxidation of PPG formulation effluent. COD removal efficiency decreased from 56 to 17% for the photo-Fenton-like process and from 44 to 14% for the dark Fenton-like process in the presence of the 1214 mg/l chloride ion (used as a free radical probe compound at acidic pH) after 30 min oxidative treatment, indicating that in both treatment processes the hydroxyl radical ( OH) was the major oxidizing agent for PPG.

Climate change in Turkey for the last half century

Abstract: Climate change and its urban-induced bias in selected Turkish cities is studied with a quality controlled temperature and precipitation data of Turkish stations in the period of 1950–2004. These stations are classified into two groups according to their populations; S1, including rural and suburban stations and S2, including large urban stations. Moving average signals, 365-day, and their digital low pass filtered versions are produced to eliminate the short term fluctuations and examine the possible trends or anomalies in climate data. Furthermore, ‘relative difference’ signals are introduced and applied to temperature and precipitation series to observe the actual local changes in the climate data independent from large-scale effects. Mann–Kendall test statistics are calculated for maximum, minimum, mean temperature and precipitation series and plotted on maps to determine any spatial trend patterns. Signal analysis show a cool period extending from early 1960s till 1993, generally with the lowest temperature values on 1992–1993 owing to the eruption of Mount Pinatubo. A last decade significant warming trend is observed in both of the series, S1 and S2, leading to 2000–2002 temperatures to be recorded as maximums in record history. The variability of urban precipitation series is generally larger than the rural ones, suggesting that urban stations can experience more frequent and severe droughts and floods. Though not significant, an increase in the urban precipitation compared to the rural one is also found. Spatial analysis resulted in significant warming in southern and southeastern parts of the country. Particularly, minimum temperature series show significant warming in almost all of the regions indicating the effect of urbanization. Significant decreases of precipitation amounts in the western parts of Turkey, such as Aegean and Trachea regions, are found. On the other hand, some Turkish northern stations show increases in precipitation of which some are significant.