Yazar "Aygun, Ahmet" seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Analyses of fruit attributes by multidimensional scaling method of apple genetic resources from coastal zone of North Eastern Anatolia, Turkey(ELSEVIER SCIENCE BV, 2018) Dumanoglu, Hatice; Aygun, Ahmet; Delialioglu, Rabia Albayrak; Erdogan, Veli; Serdar, Umit; Kalkisim, Ozgun; Bastas, KubilayNorth Eastern Anatolia had a significant contribution to development of cultivated apple. A lot of local apple genotypes have been successfully grown without any pesticide applications despite to high rainfall (900-2300 mm) and humidity (70-85%) especially at the coastal part of the Eastern Black Sea Region of North Eastern Anatolia. We have investigated and selected local apple genotypes from the region which could be of importance for apple breeding by fruit attributes. In this study, sensory characteristics (186 accessions) and quantitative characteristics (176 accessions) determined based on Apple Descriptor, and were analyzed by Multidimensional Scaling analysis. Harvest maturity dates classified the genotypes into early season (19), mid season (13) and late season (154) apples. Among the genotypes, 39.25% had medium-sized fruits, 53.23% had intermediate attractiveness, 50% had ground color of green-yellow, 59.68% had skin over color of red, 61.29% had good eating quality and 53.76% had fine flesh texture. Quantitative characters showed large variation that fruit weight ranged from 27.4 g to 246.4 g, SSC from 8.6% to 15.4%, TA from 0.08% to 2.24%. Multidimensional Scaling analysis indicated that the genotypes harvested in early and mid-season exhibited larger variation for sensory and quantitative characteristics than did late season apples. Although several genotypes were differentiated for investigated characteristics and/or variables in early and late season groups, mid-season apples did not tend to form any cluster.Öğe APPLICABILITY OF FENTON-LIKE PROCESS FOR DECOLORIZATION OF REACTIVE BLACK 5 BY USING RAW LIMONITE ORE(INT SCIENTIFIC CONFERENCE SGEM, 2008) Guclu, Dunyamin; Sahinkaya, Serkan; Aygun, Ahmet; Sevimli, Mehmet FaikThe Fenton process, one of advanced oxidation processes (AOPs), has been widely implemented to remove COD and color for dye wastewater as a pre-treatment or post-treatment process. In recent years, Fenton-like processes have received considerable attention in wastewater removal. The main purpose of the present study was to determine the optimal operational conditions of the Fenton- like process by using raw limonite ore at various concentrations of hydrogen peroxide and raw limonite ore for treatment of dye wastewater on a laboratory scale synthetic wastewater. According to the experimental results, it is indicated that this method can effectively reduce concentrations of color. Under optimal conditions, 98 % removal efficiency was achieved.Öğe Application of sequencing batch biofilm reactor for treatment of sewage wastewater treatment: effect of power failure(DESALINATION PUBL, 2014) Aygun, Ahmet; Nas, Bilgehan; Berktay, Ali; Ates, HavvaThe operational performance of the sequencing batch reactor (SBR) and sequencing batch biofilm reactor (SBBR) for treating the university campus wastewater was evaluated. The effects of power failure on performance of processes were investigated by comparing chemical oxygen demand (COD) and total suspended solids (TSS) removal, sludge settling properties and microorganism's morphological properties by using SEM photos. The experiments were carried out at four 2-L reactors made from plexiglas. Three in four reactors were operated as SBBR. SBBRs were filled with the kaldnes biomedia K1 to 40, 50 and 60% of the volume of empty reactor. SBR and SBBRs were operated at 6/24 h cycling periods on a day that consisted of wastewater fill (30 min), reaction (4 h), settling (1 h) and draw (30 min), summed up to 6 h with the hydraulic residence time of 7.5 h. The effect of filling ratio on SBBR performance was also determined. In normal operation, average COD removal rates were calculated as 86, 88.5, 90.6 and 94.2% for SBR, SBBR1, SBBR2 and SBBR3, respectively. Power failure is one of the most encountered problems in the small wastewater treatment plants. Its effect was observed at 1 cycle as short term and 4 cycles as long term. Besides the negative effects of the power failure on COD and TSS removal, it also affects sludge settling properties. While interruption time is increased, recovery took much more time than expected to reach steady state conditions for all the reactors. However, the presence of biofilm restricted the adverse effect of power failure. SEM photos and better effluent quality supported these findings.Öğe THE DECOLORIZATION OF REACTIVE BLUE 21 BY USING FENTON REAGENT(INT SCIENTIFIC CONFERENCE SGEM, 2008) Sevimli, Mehmet Faik; Sahinkaya, Serkan; Aygun, AhmetThis study was focused on the application of Fenton (Fe(+2)/H(2)O(2)) process for the decolorization of colored synthetic wastewaters. Polyvinyl alcohol (PVA) and C.I. Reactive Blue 21 (RB 21) were used as model pollutants. The selection of the optimal operating conditions (initial concentration of H(2)O(2) and Fe(2+)) was performed in a batch reactor. The optimal reacting conditions were experimentally determined and it was found to be initial [H(2)O(2)] 20 mg/L, [Fe(+2)] 37.5 mg/L for synthetic wastewater containing [RB 21] 50 mg/L and [PVA] 100 mg/L at pH 3 with room temperature.Öğe THE DEGRADATION OF REACTIVE BLACK 5 BY FENTON PROCESSS USING RAW IRON PYRITE ORE(INT SCIENTIFIC CONFERENCE SGEM, 2008) Aygun, Ahmet; Sahinkaya, Serkan; Sevimli, Mehmet FaikThis study examined the decolorization of one of the most commonly used reactive dye by using the Fenton-like process [Iron pyrite/H(2)O(2)]. Raw iron pyrite ore contains 28,68 % Fe. Oxidation experiments were run in 500 mL-glass beakers that were continuously stirred for up to 180 min at a constant rate of 200 rpm, after initiation of the Fenton process. A series of experiments were carried out at various concentration of hydrogen peroxide and raw iron pyrite ore while the pH value was kept constant at 3 in order to determine the optimum conditions of these. From 50 mg/L to 750 rng/L of raw iron pyrite ore and 5 to 75 rng/L dosage of H(2)O(2) were applied for the determination of operational conditions. The decolorization of RB 5 was measured with UV-Vis spectrophotometer. Manganese oxide (MnO(2)) was used for quenching H(2)O(2) to prevent any interference after sampling. It was found that optimum dosages of H(2)O(2) and raw iron pyrite ore were 37,5 mg/L and 300 mg/L, respectively. At the optimum conditions color removal was 92,8 %. The experiments indicate that RB 5 can be effectively decolorized textile effluent by Fenton like process which uses pyrite as the iron source.Öğe Influence of High Organic Loading Rates on COD Removal and Sludge Production in Moving Bed Biofilm Reactor(MARY ANN LIEBERT, INC, 2008) Aygun, Ahmet; Nas, Bilgehan; Berktay, AliA moving bed biofilm reactor ( MBBR), where biomass is attached to small carrier elements that move freely along with the water in the reactor, has been tested for organic matter removal at five different organic loading rates. A lab-scale reactor with a volume of 2L was built and fed continuously with synthetic wastewater. The reactor was filled with the Kaldnes biomedia K1 which is used in the patented Kaldnes Moving Bed (TM) biofilm process at 50% of the volume of empty reactor. Hydraulic retention times (HRT) in the reactor and in the settler were adjusted to between 8 and 4 hours, respectively. A start-up period of about 4 weeks for biofilm growth on the carrier was followed by 10 weeks of testing period. By changing the wastewater composition, the operation of the system was adjusted, one after the other, to five different organic loading rates: 6, 12, 24, 48 and 96 g COD/m(2).d. Organic removal efficiency decreased with increasing organic loading rate, ranging from 95.1%, 94.9%, 89.3%, 68.7% and 45.2% as the organic loading rate was increased form 6 to 96 g COD/m(2).d. In the MBRR reactor, the biofilm reached an average concentration of 3.28 kg TSS/m(3) at the highest organic loading rate. The ratio between the TSS production and the total COD removal was 0.12 kg TSS/kg total COD at an influent total COD of 500 mg/l.Öğe Seasonal and spatial variability of metals concentrations in Lake Beysehir, Turkey(TAYLOR & FRANCIS LTD, 2009) Nas, Bilgehan; Berktay, Ali; Aygun, Ahmet; Karabork, Hakan; Ekercin, SemihLake Beysehir is the largest fresh water lake and also the largest reservoir for drinking, and irrigation water in Turkey. The lake has an area of 656 km2 with an average depth of 5 m. Metal concentrations of aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) were determined in Lake Beysehir on 9 June and 19 August 2005, and 12 June and 22 August 2006. The water samples were collected from 40 sampling stations. The aim of this research is to determine metal concentrations and their seasonal and spatial variability in the lake. Generally, metal concentrations of Lake Beysehir were found to decrease in the sequence of Fe Al Zn Cr Ni Pb Cu Cd as 92.8, 81.8, 7.4, 2.7, 2.2, 1.9, 1.7 and 0.5 g L-1, respectively. The results showed that the mean concentrations of the metals in the lake water did not exceed WHO (World Health Organization), US EPA (Environmental Protection Agency) or TWQCR (Turkish Water Pollution and Control Regulations) drinking water guidelines. On the other hand, maximum levels of metals sporadically exceeded these standards in some sampling stations, especially for Al, Cr, Fe, and Pb.Öğe TREATMENT OF YOUNG LANDFILL LEACHATE BY FENTON PROCESS(INT SCIENTIFIC CONFERENCE SGEM, 2008) Aygun, Ahmet; Yilmaz, Tuba; Berktay, Ali; Nas, BilgehanIn this Study leachate from solid waste landfill in Konya Municipal area was used. Landfill occupies 24 ha area with ail average height of 8 m in the total area of 350 ha at the present time. The amount of solid waste generated is about 800-850 tons/day in summer and 950-1,000 tons/day in winter months yielding the average leachate flow rates of about 100 m(3)/day. The main characteristics of the leachate are chemical oxygen demand in the range of 7,500-55,000 mg/L, biological oxygen demand after 5 days of 4,000-36,500 mg/L. It is observed that presenting a relatively high value of COD and BOD5 and the rate of COD/BOD5 values indicate that the leachate call be defined as young. The aim Of this Study is to investigate the leachate treatability by using fenton process. There are a number of studies on treatment of old leachate with fenton but ill this study Young landfill leachate was used and removal efficiencies of color and organic matter as COD were investigated. For this purpose Suitable conditions were accepted as optimum pH = 4.0, optimum Fe+2 = 3000 mg/L and optimum H2O2 = 10 000 mg/L.
