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Öğe Comparative performance of RBC operated under pressure and open to the atmosphere at high loading conditions(MARY ANN LIEBERT INC, 2005) Berktay, A; Ellis, KVThe aim of this research was to investigate the effects of pressure on aerobic biological wastewater treatment processes. For the purpose of the investigation two specially designed, identical, laboratory-scale rotating biological contactor (RBC) units were constructed. One of these was held in a steel pressure vessel while the other, as reference unit, was operated open to the atmosphere. The treatment capabilities of the pressurized unit, compared to those of the reference unit, were determined for a variety of organic loading rates at a 5-bar pressure. The unit under pressure was able to produce a much better effluent, in comparison with the reference unit when operating at higher loading conditions. The filtered BOD5 in the effluent from the unit under pressure was always less than 10 mgL(-1), whereas the sludge yield coefficient was as low as 0.21 kg dry solids/kg BOD5 removed, even with the unit loaded even at an organic loading rate of 27.0 g BOD5/m(2) (.) day. However, the development of the nitrification decreased sharply as the organic loading increased. The indication is that the unit under pressure is able to operate over a wide range of loading with a small variation in the effluent quality. The principal benefits of increasing pressure were recorded to be significantly improved nitrification and a decrease in the sludge yield coefficient.Öğe Comparison of the cost of the pressurized wastewater treatment process with other established treatment processes(PERGAMON-ELSEVIER SCIENCE LTD, 1997) Berktay, A; Ellis, KVA biological wastewater treatment unit under the influence of pressure was operated at pressures of up to 6 bar. It was demonstrated the capability of operating effectively with high carbonaceous oxidation and nitrification efficiencies at loadings of up to 13 g BOD m(-2) day. Another advantage of the pressurized treatment unit was observed to be its low sludge production. The cost of the pressurized treatment unit has, however, become an important factor for the applicability of the pressurized treatment unit. An investigation was carried out to determine the approximate cost of a proposed full-scale pressurized unit. The comparison between the pressurized unit and the established treatment processes were made for three populations of 500, 1000 and 3000 persons. The costs were then compared with those of various other conventional biological treatment processes capable of treating an equivalent wastewater load. The conventional processes selected for comparison were the activated sludge, biological filtration and conventional RBC. The sludge disposal cost for the pressurized unit was appreciably lower than that for the other processes. The results indicated that the cost of the pressurized unit (present value for a 20-yr period) and the costs of the activated sludge and conventional RBC processes were found to be similar for the smaller populations. However, a substantial saving could be obtained with the pressurized unit for the larger populations. In addition, there was an indication that the land requirement of the pressurized treatment unit decreased appreciably as the flow rate increased. (C) 1997 Elsevier Science Ltd.Öğe Electrical energy prices and losses respect to Turkish social-economic situations(MULTI SCIENCE PUBL CO LTD, 2004) Berktay, A; Demirbas, A; Kocak, S; Nas, BElectricity is a basic part of nature and it is one of the most widely used forms of energy. Electricity, which is a secondary energy source, can be generated from the conversion of other sources of energy, such as coal, natural gas, oil, nuclear power and renewable resources. Electricity prices have a deep impact on the competitiveness of a country's industry. Some electricity losses may occur during the process of transmission and distribution from generators to consumers. Generally there are two types of losses, one is technical losses which cover transmission losses and the other is non-technical losses including distribution losses and the incidence of illegal usage. The aim of this paper is to present the electricity usage and prices and is also to focus on the electricity losses occur both technical and non-technical means. An "electricity losses map" was produced to illustrate the electricity losses. For this purpose, a vector-based Geographic Information System (GIS) software package Arc GIS 8.3 was employed to map the data. The rate of losses within the electricity provided to the national network was about 19% in Turkey. The incidence of illegal usage and hence the rate of non-technical losses could be reduced dramatically through establishing regular action.Öğe Groundwater contamination by nitrates in the city of Konya, (Turkey): A GIS perspective(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2006) Nas, B; Berktay, AGroundwater is an essential drinking water source in the city of Konya, Turkey. Approximately 75% of the city's water consumption has been supplied from 198 groundwater wells for the last six years. Nitrate (NO3-) is one of the important water quality parameters and was measured in the water samples taken from 139 wells in 1998 and from 156 wells in 2001 within the study area of 427.5 km(2). To evaluate the nitrate data, a vector-based GIS software package ArcView GIS 3.2 was used. A hardcopy map of the city was digitized in the UTM projection system. The locations of the wells were obtained by a hand-held Global Positioning System (GPS) receiver. According to the maps produced, nitrate concentrations generally tend to increase in the city center, the average concentrations being 2.2 and 16.1 mg/L for the years of 1998 and 2001, respectively. A statistical correlation procedure was also applied to well depths and nitrate concentrations. As a result, correlation coefficients of 0.259 and 0.261 were obtained for data collected in 1998 and 2001. It is concluded that the distribution of nitrate concentrations is not correlated with well depths within the study area. (c) 2005 Elsevier Ltd. All rights reserved.
