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In this study, the production of two-stage metal-free catalysts from pistachio shells, which are abundant in Turkey and the world, is designed. The first stage of the study includes activated carbon(AC) production, and the second stage includes the production of heteroatom-doped catalysts as a result of hydrothermal heating of the obtained activated carbon with nitric acid. These metal-free catalysts obtained were used for the production of hydrogen (H2) from sodium borohydride (NaBH4) in methanol. In H2 production experiments, the NaBH4 concentration effect, temperature effect and catalyst amount effect and catalyst reusability parameters were investigated. HGR values obtained from the methanolysis using metal-free catalysts treated by the nitric acid/water ratio: 1:2, 1:3, 1:4, 1:5 are 8041, 8955, 10600 and 8333 ml min−1 g−1, respectively. The activation energy (Ea) of the production of H2 from NaBH4(NaBH4–H2–P) in methanol by the metal-free catalyst was 18.19 kJ mol−1. Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), CHNS elemental analysis, scanning electron microscopy (SEM), and nitrogen adsorption analyses were performed for the characterization of the metal-free catalysts obtained. In addition, the mechanism of the obtained metal-free catalysts on the NaBH4–H2–P in methanol is discussed. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the interactions between diatoms and ecological factors in various streams and to test the suitability of diatom indices to evaluate the ecological status of 44 streams in the Ceyhan River Basin during the spring and autumn periods of 2021 and the summer of 2022. Canonical correspondence analysis indicated the significant effects of electrical conductivity (EC), dissolved oxygen, biological oxygen demand (BOD 5 ), total phosphorus (TP), and total nitrogen (TN) on the distribution of diatom species of streams in the Ceyhan River Basin. Of the streams, Aksu and Erkenez streams were associated with high EC, BOD 5 , and TP and characterized by pollution-tolerant species. Pollution-sensitive species showed close integration with Aksu Spring Brook, Gözpınar Creek, Göksun Creek, and Yeşilgöz Spring Brook, which related to a high dissolved oxygen gradient. Different eco-regional diatom indices displayed different scores, representing from bad to high ecological status in the Ceyhan River basin. Among the diatom indices, Trophic Index Turkey (TIT) proved to be the more suitable metric to assess the ecological status of streams. TIT indicated deterioration of water quality in Karasu (S06), Erkenez (S07) streams, and downstream areas of the Ceyhan River and the least distributed sampling stations in the basin. Results suggested that eco-regionally developed diatom indices, like TIT, are required to more accurately assess the ecological status of streams in the Mediterranean region. The study provides a fundamental assessment of the ecological status of streams in the Ceyhan River Basin using an appropriate diatom index before the Pazarcık-centered earthquake on February 6, 2023. Findings allow someone to assess the impact of the earthquake on diatom communities and ecological factors in the region in the future studies., (© 2024. The Author(s).)

Determining the water quality status of a river and accurately identifying potential pollution sources threatening the river are pillars in effective control of pollution and sustainable water management. In this study, water quality indices, multivariate statistics and absolute principal component score-multiple linear regression (APCS-MLR) were applied to evaluate the water quality of the Karasu River, the main tributary of the Euphrates River (Turkey). For this, 19 water quality variables were monitored monthly at eight stations along the river during one year. Based on the mean dissolved oxygen (DO), electrical conductivity (EC), nitrate-nitrogen (NO 3 -N), orthophosphate-phosphorus (PO 4 -P), total phosphorus (TP), ammonium-nitrogen (NH4-N), chemical oxygen demand (COD) and total nitrogen (TN) levels, most stations of the river had "very good" water status according to surface water quality criteria. Spatial cluster analysis (CA) divided eight stations into three regions as clean region, moderate clean region and very clean region. The mean values of Nutrient Pollution Index indicated that the river was "no polluted". Similarly, Water Quality Index and Organic Pollution Index values indicated that the river water quality was between "good" and "excellent". A minimum water quality index (WQI min ) consisted of ten crucial parameters was not significantly different with the WQI based on all the 17 parameters. Discriminant analysis (DA) results showed that water temperature (WT), EC, chlorophyll-a (Chl-a), potassium (K), calcium (Ca), NO 3 -N and COD are the variables responsible for temporal changes, while WT, total dissolves solids (TDS), Chl-a, K, magnesium (Mg), Ca, NH 4 -N and COD are the variables responsible for spatial changes in the river water quality. Principal component analysis/factor analysis (PCA/FA) identified four potential sources, including anthropogenic, natural, seasonal and phytoplankton. Source apportionment in the APCS-MLR model revealed that seasonal and anthropogenic sources contributed 35.2% and 25.5% to river water quality parameters, respectively, followed by phytoplankton (21.4%) and natural sources (17.9%)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

At Aşıklı Höyük, one of the earliest Pre-pottery Neolithic mound sites in Central Anatolia, a shift in animal utilization from broad-spectrum exploitation of diverse animal species to a concentration on managed caprines has been observed. Changes in the balance of meat to plant foods over the same time frame remain an open question. In this study, carbon and nitrogen isotopic analyses of bulk collagen and compound-specific nitrogen isotopic analysis of amino acids were undertaken for the human remains to elucidate the dietary impact of the hunting to herding transition over a span of about 1000 years. The results showed that animal protein consumption did not change very much as managed sheep became the main source of meat. The contribution of animal protein to the total human diet at Aşıklı Höyük is similar to comparison data on later Neolithic farmers in Anatolia measured in previous studies. The early development of ungulate management and the increasing focus on just a few prey species do not appear to have forced drastic changes in the extent human carnivory from the early Pre-pottery Neolithic to the early Pottery Neolithic. However, human individuals showed similar isotopic compositions within the same buildings at Aşıklı, suggesting variation in food consumption by household. • This study reconstructs the diets of early pastoral societies in southwest Asia. • At Aşıklı Höyük, a shift of subsistence from hunting to sheep herding was observed. • Nitrogen isotopic analysis of amino acids provides new information on the rate of animal protein intake. • The animal protein consumption did not change despite major change from hunting economy to highly dependent on managed sheep. • The similarity of the human isotopiccompositions is greatest by building and suggests uniform diets within households. [ABSTRACT FROM AUTHOR]

The relationships between nutrients and the trophic state of Borçka dam reservoir in the Çoruh River Basin, which is located in the Eastern Black Sea region of Turkey, were evaluated using the trophic state index (TSI), trophic level index (TLI), and statistical analysis. The samples data were analyzed for chlorophyll-a (Chl-a), total phosphorus (TP), total nitrogen (TN), and secchi disk (SD). In the evaluation, according to the TSI' TLI and Turkish legislation, the reservoir is assessed as mesotrophic in terms of TP, TN data of the water quality. The measurement results of these parameters are higher at the depth points and lower on the surface. The Chl-a parameter is evaluated mesotrophic with 2013 data at the depth, and oligotrophic with 2016 data. The result of TSI (Chl-a) < TSI (SD), TSI (Chl-a) < TSI (TP), and TSI (TN) indicate non-algal turbidity. At the same time, this was verified by calculating the non-algal turbidity coefficient (Kna). It is observed that there is a low correlation between Chl-a and Kna, however a low correlation with TN, and a high correlation with TP. Non-algal particles in the dam lake may occur due to surface runoff and soil erosion from the agricultural area and human settlements. Regression analysis was conducted to determine the relationship between nutrients and Chl-a. The relationship of Chl-a concentration with TN, TP, and TN/TP concentrations is weak. This supports that there are inorganic suspended solids (non-volatile suspended solids) with high underwater light availability.Graphical abstract.

In this study, characteristics of effluents from three flow-through rainbow trout farms in Turkey and their impact on water quality and epilithic algal communities of the receiving stream were investigated. Water samples were taken monthly from both inlets and outlets of three fish farms, while both water and epilithic algae samples were collected from two stations (upstream and downstream) in the stream. A significant increase from inlets to outlets was observed for chemical oxygen demand (COD), soluble reactive phosphorus (SRP), total suspended solids (TSS), NH 4 -N and total phosphorus (TP) (p < 0.05) due to no effluent treatment processes and high FCR at the fish farms. The daily average total nitrogen (TN) and TP fluxes of the fish farms predicted with the nutritional method were found close to those measured with the hydrological method. Although there were significant increases in COD, TSS, NH 4 -N, TN, NO 3 -N, NO 2 -N, TP and SRP concentrations at the downstream station compared to the upstream station of the receiving stream (p < 0.05), water quality of the downstream station remained in Class I in terms of examined parameters. Trophic Diatomic Index and Biological Diatom Index values indicated that the upstream station had a better water quality than the downstream station. Also, filamentous algae such as Cladophora glomerata, Ulothrix zonata and Stigeoclonium lubricum were observed at the downstream station. In view of the above findings, several suggestions were put forward to protect the water quality of the receiving stream., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The extensive use of synthetic fertilizers is increasing continuously to meet the growing demand of food worldwide. This excessive use of fertilizer not only pose a threat to the sustainability but also cause negative externalities in form of hidden social cost to the society The present study estimated social costs and benefits associated with excessive use of chemical fertilizers at tea farms and also evaluated eco-efficiency of tea growers in Rize Province of Turkey. Data envelopment analysis (DEA) was used in this study. Tea growers are 68% eco-efficient in the locality. They can reduce their average fertilizer use from 115.45 to 66.45 kg and labor from 9.88 to 8 days per decare. The overuse of fertilizers at tea farms emits 289.3 kg/hectare of greenhouse gases. Therefore, by applying the eco-efficient fertilizer target level, 1574.48 tons of gas emissions only in Rize Province and 23,997.57 tons in whole Turkey can be reduced. The cost of 1 kg gas emissions was calculated as 0.3316 TL. The optimal level of fertilizers (social costs = social benefits) was also similar to the target level. The fertilizer use efficiency analysis showed that the tea growers cannot only reduce their fertilizer quantity by 49.03 kg/decare without compromising the crop yield, but can also contribute to the healthy environment with a low level of greenhouse gas emissions. Tea growers should replace their older tea orchards with new ones in order to achieve social and eco-efficient levels as well as to maintain viable yield level.

Legumes are very important both ecologically and agriculturally, as well as economically since soil quality can be improved by the added nitrogen and increased organic matter content they provide. It can be advantageous to apply quantitative methods to indicate soil quality using a dataset of soil characteristics that includes microbial biomass content and activity. The Western Black Sea Region of Turkey was chosen as the study area with the aim of determining the variations in the soil characteristics (physical, chemical, and microbiological) in diverse croplands. At the sites sampled, marked differences were found in the bulk density, clay, soil temperature, soil moisture content, organic carbon, total N, C org /N total ratio, and microbial characteristics of vetch (Vicia sativa L.), alfalfa (Medicago sativa L.), and sainfoin (Onobrychis sativa L.) croplands. There was a significant increase (P < 0.05) in the microbial biomass carbon content in the alfalfa (709.27 μg g -1 ) and sainfoin (607.22 μg g -1 ) croplands compared with the vetch (558.07 μg g -1 ) cropland. Microbial biomass nitrogen was significantly lower in the vetch (103.67 μg g -1 ) cropland compared with that in the sainfoin (127.42 μg g -1 ) and alfalfa (140.26 μg g -1 ). The highest basal respiration was determined in the alfalfa (1.09 μg CO 2 -C g -1 soil h -1 ) cropland, while the lowest was found in the vetch (0.54 μg CO 2 -C g -1 soil h -1 ) cropland. The mean C mic /C org percentage of the soils was lower in the sainfoin cropland when compared with the other croplands; however, statistically, no difference (P > 0.05) was observed among them. The soil under Onobrychis sativa L. and Vicia sativa L. exhibited the highest (1.67 mg CO 2 -C g -1 C mic h -1 ) and lowest (1.03 mg CO 2 -C g -1 C mic h -1 ) mean metabolic quotients (qCO 2 ), respectively. When the microbial biomass carbon and nitrogen were taken into account, the high qCO 2 values may have been an indication that the microbial biomass of decomposed organic compounds was more active, rather than signifying a result of metabolic stress. Consequently, it can be said that the variations found in the metabolic quotient, basal respiration, and microbial biomass among the different croplands were related to changes in microbial activity. Furthermore, the physical, chemical, and microbiological results indicated that the soils of Medicago sativa L. and Onobrychis sativa L. were of higher quality than the Vicia sativa L. soil.

The Keban Reservoir, which is the second man-made waterbody in Turkey, has the biggest rainbow trout production in the country. In this study, the impacts of rainbow trout farms on water and sediment chemistry were investigated. Water and sediment samples were taken at distances of 0, 10, 25, 50 and 100 m from the edge of the cages at the three fish farms, and at the respective reference stations. Samples were also taken at 0 m stations and reference stations in the late August when there were no fish in the cages. Physico-chemical variables and trace metals were analysed in all samples. Due to likely high dilution rates and recycling processes in the water column of the reservoir, little changes in the water quality parameters associated with wastes of the fish farms were noticed. When compared with those in the sediment samples at the stations near the edge of cages, the lower concentrations of total phosphorus (TP), total nitrogen (TN), organic matter (OM), total carbon (TC), sulfide (S 2- ), arsenic (As), cobalt (Co), copper (Cu), manganese (Mn) and zinc (Zn), and higher values of redox potential (Eh) were found at the reference stations. According to organic enrichment classification based on S 2- and Eh values, sediments of the three fish farms in the period when there were fish in the cages fell into the oxic category, whereas sediments in the August (no fish farming activity) fell into the normal category. Also, it was found in the August that most of sediment quality parameters at the 0 m stations had close values to those at the reference stations. These results revealed that a three-month period when there were no fish in the cages allows for sediments to return to reference station conditions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The seasonal succession of phytoplankton functional groups (PFGs), their ecological preferences, relationships between environmental variables and PFGs, and ecological status were investigated in the Batman Dam Reservoir, a warm monomictic reservoir, located in the Tigris River basin of Turkey. Altogether 60 species, 19 functional groups, and 10 prevailing functional groups were identified, and prevailing functional groups showed strong seasonal changes. Centric diatoms Cyclotella ocellata (group B) and Aulacoseira granulata (group P) were dominant in the spring, with water mixing and low temperature. Groups F (Elakatothrix gelatinosa, Elakatothrix gelatinosa, and Sphaerocystis schroeteri), J (Pediastrum simplex and Coelastrum reticulatum), G (Eudorina elegans and Volvox aureus), L M (Ceratium and Microcystis), and H1 (Aphanizomenon flos-aquae and Anabaena spiroides) dominated the phytoplankton community from summer to mid-autumn, with thermal stratification. Groups H1 and P became dominant in the late autumn, with the breakdown of stratification. With the deepening of the mixing zone, groups P and T (Mougeotia sp.) were dominant in the winter. The reservoir was meso-eutrophic according to trophic state index values based on total phosphorus (TP), chlorophyll a, Secchi depth and total nitrogen, habitat preferences of PFGs, and diversity indices of phytoplankton. Redundancy analysis (RDA) revealed that NO 3 -N, SiO 2 , TP, pH, and water temperature (WT) were the most important environmental factors controlling PFGs in the BDR. Weighted averaging regression results indicated that among PFGs, groups F and T had a narrower tolerance range for WT, pH, and SiO 2 , while groups G and T had a narrower tolerance range for TP and NO 3 -N.

Twenty one species of microalgae and Cyanobacteria were isolated from different ecosystems in Turkey to investigate the relation between biochemical methane potential (BMP) and biochemical characterization. Since the highest dry weight (X), specific growth rate (µ) and maximum productivity (P max ) were obtained from the five species, identification of species and BMP tests with the composition analyzes were examined. BMP values were determined 308, 293, 242, 229 and 230 mLCH 4 /gVS for Desertifilum tharense, Phormidium animale, Chlorella sp., Anabeana variabilis and Chlorophyta uncultured. The Pearson correlation and principal component analysis (PCA) were applied to extract and clarify the correlation between composition of species and their methane production. Pearson correlation shows that glucose, Kjeldahl nitrogen and chlorophyll are highly and positively correlated with BMP. PCA revealed that Chlorella sp., Chlorophyta uncultured and Desertifilum tharense were placed against Phormidium animale distinguished by its extreme and different profile because of Kjeldahl nitrogen and glucose content., (Copyright © 2019. Published by Elsevier Ltd.)

Rivers export increasing amounts of dissolved inorganic (DIN, DIP) and organic (DON, DOP) nitrogen and phosphorus to the Black Sea causing coastal eutrophication. The aim of this study is to explore future trends in river export of these nutrients to the sea through a sensitivity analysis. We used the Global NEWS (Nutrient Export from WaterSheds) model to this end. We calculated that between 2000 and 2050 nutrient inputs to the Black Sea may increase or decrease, depending on the assumed environmental management. We analyzed the effects of agricultural and sewage management on nutrient inputs to the sea in 2050 relative to two Millennium Ecosystem Assessment (MEA) scenarios, Global Orchestration (GO) and Adaptive Mosaic (AM). In these baselines, total N and P inputs to the Black Sea decrease between 2000 and 2050, but not for all rivers and nutrient forms. Our results indicate that it is possible to reduce nutrient inputs to the sea further between 2000 and 2050 in particular for dissolved inorganic N and P and for many river basins, but not for all. For scenarios assuming combined agricultural and sewage management dissolved inorganic N and P inputs to the Black Sea are reduced by up to two-thirds between 2000 and 2050 and dissolved organic N and P inputs by one-third. River export of DIN is mainly affected by agricultural management and that of DIP by sewage management. On the other hand, in scenarios assuming increased fertilizer use for, for instance bioenergy crops, nutrient inputs to the sea increase. An increase in DIP inputs by southern rivers seems difficult to avoid because of the increasing number of people connected to sewage systems., (© 2013 Elsevier B.V. All rights reserved.)

The paper presents new studies about the removal efficiencies and characterization of the Municipal Wastewater Treatment Plant (MWWTP) in Kayseri, Turkey, which is serving for 800,000 population equivalents with the capacity of 110,000 m(3)/day, between 2006 and 2009. Kayseri discharges its effluents to Karasu Creek that downstream joins the Kizilirmak river, the longest river in Turkey discharging into the Black Sea. Four years of operation data between 2006 and 2009 calendar years were obtained from KASKI General Directorate. Influent and effluent samples were collected daily and suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand in 5 days (BOD(5)), total nitrogen (TN), and total phosphorus (TP) were measured, aiming to study the evolution of the removal efficiencies for each year. The following yearly mean removal efficiencies were performed in the treatment plant: 94%, 97%, 97%, 95% for SS; 94%, 96%, 95%, 95% for COD; 98%, 98%, 98%, 98% for BOD(5); 84%, 87%, 89%, 82% for TN; and 71%, 86%, 80%, 86% for TP, in 2006, 2007, 2008, and 2009, respectively. The performance of Kayseri MWWTP was given both in terms of influent and effluent quality and in comparison with the current legislation on discharge limits to the receiving body. During the studied period, mean concentrations in the effluent did not exceed the imposed limits, but sometimes, higher values were noticed for SS, TN, and TP. In conclusion, the plant performances concerning these parameters were excellent and Kayseri MWWTP was operating efficiently according to the conventional control parameters.

Spatial (10 different locations) and temporal (2 years) changes in characteristics of the Marmara Sea Sediments were monitored to determine interactions between the chemical and microbial diversity. The sediments were rich in terms of hydrocarbon, nitrate, Ni and microbial cell content. Denitrifying, sulfate reducing, fermentative and methanogenic organisms were co-abundant in 15 cm below the sea floor. The local variations in the sediments' characteristics were more distinctive than the temporal ones. The sulfate and nitrate contents were the main drivers of the changes in the microbial community compositions. N and P were limited for microbial growth in the sediments, and their levels determined the total cell abundance and activity. Seasonal shifts in temperatures of the shallow sediments were also reflected in the active cell abundances. It was concluded that the Marmara Sea is a promising ecosystem for the further investigation of the ecologically important microbial processes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The objective of this study was to devise and validate simple models for estimating spatio-temporal dynamics of seven optically (in)active biogeochemical properties in Mersin Bay using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data and GIS. Spatio-temporal dynamics of Secchi depth (S (depth)), dissolved oxygen (DO), nitrite nitrogen (NO(2)-N), nitrate nitrogen (NO₃-N), silicate (SiO₄), 5-day biological oxygen demand (BOD5), and chlorophyll-a (Chl-a) were estimated using best-fit multiple linear regression (MLR) models as a function of Landsat 7 ETM+ and ground data in 2007 and 2008, latitude, longitude, and day of year. Validation of the MLR models against Landsat and ground data in 2005 led to r values ranging from 0.39 for NO₂-N (P = 0.008) to 0.79 for S (depth) (P < 0.001). Parsimonious MLR models built in this study appear to be promising for monitoring and predicting spatio-temporal dynamics of optically (in)active water quality characteristics in Mersin Bay.

Recent research in catchments of rapidly developing countries such as Brazil and China suggests that many catchments of the developing world are already showing signs of nitrogen pollution reminiscent of past experiences in developed countries. This paper looks at both the individual and combined effects of future climate change and other likely environmental changes on in-stream nitrate concentrations in a catchment in Northern Turkey. A model chain comprised of simulated future temperature and precipitation from a Regional Circulation Model (RCM), a conceptual hydrological model (HBV) and a widely tested integrated catchment nitrogen model (INCA-N) is used to model future changes in nitrate concentrations. Two future periods (2021-2050 and 2069-2098) are compared to the 1961-1990 baseline period in order to assess the effectiveness of several possible interventions available to catchment authorities. The simulations show that in the urbanised part of the catchment, the effects of climate change and other environmental changes act in the same direction, leading to peak nitrate concentrations of 7.5 mg N/l for the 2069-2098 period, which corresponds to a doubling of the baseline values. Testing different available policy options reveals that the installation of wastewater treatment works (WWTWs) in all major settlements of the catchment could ensure nitrate levels are kept at near their baseline values for the 2021-2050 period. Nevertheless, a combination of measures including WWTWs, meadow creation, international agreements to reduce atmospheric N concentrations and controls on agricultural practises will be required for 2069-2098. The approach presented in this article could be employed in order to anticipate future pollution problems and to test appropriate solutions, some of which will necessitate international co-operation, in other catchments around the world., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Capture-based aquaculture of Atlantic bluefin tuna in the Mediterranean has been expanding rapidly but little is known about its environmental impact. In order to understand the consequences of this new sector, long-term monitoring is needed. For this purpose, we investigated the impact of a capture-based tuna farm located in the Gerence Bay (Aegean Sea) on the water column on a seasonal basis from 2005 to 2008, where in the water column, temperature, salinity, pH, dissolved oxygen, nutrients (nitrite, nitrate, ammonium, and phosphate), and chlorophyll a, in the sediment organic carbon variables were measured. Although highest nutrient concentrations were observed at the cage station as compared to the two controls in the production period, differences were not statistically significant between stations. Monitoring of physico-chemical parameters, nutrients, and chlorophyll a in water column together with organic carbon in sediment did not show detectable impact of fattening of Atlantic bluefin tuna. This was probably caused by strong currents present in the area, location of the cages away from the coast, hence high water depth, controlled feeding, and periodic presence of tuna farming activity in the study area.

The study comprised modification of the Canadian Council of Ministers of the Environment (CCME) Water Quality Index (CCMEWQI) to obtain a tool in classification of surface waters according to quality defined by the European Legislation-75/440/EEC. Three categories were proposed, and the category ranges of CCMEWQI have been modified depending on the objective chosen. The application of the CCMEWQI with modified categorization scheme was demonstrated to assess overall water quality by integrating observed water quality determinants in the Kucuk Menderes Basin, Turkey. In this scope, the samples analyzed for pH, total dissolved solids (TDS), chlorides (Cl), nitrate-nitrogen (NO3-N), dissolved oxygen (DO), biochemical oxygen demand (BOD5), sulfate (SO4), and boron (B), variables taken monthly over 2 years from the five monitoring sites, were processed. Results revealed that the overall surface water mainly fell within the A2 water class. The CCMEWQI with modified categorization scheme is believed to assist water managers to integrate and interpret the picture of overall water quality based on the European legislation concerning the quality required of surface water intended for the abstraction of drinking water in the Member States (75/440/EEC).

The epipelic algae of Balik lagoon and Uzun lagoon were investigated from May 2003 to December 2004. A total of 106 taxa were identified. Of these, 85 were found in Balik lagoon and 78 were found in Uzun lagoon. Water temperature of the lagoons ranged from 6.5 to 24.5 degrees C during the sampling period. Conductivity hardness, dissolved oxygen an pH values varied between 0.70 and 8.00 mS, 26.00 and 86.60 degrees f, 3.50 and 9.00 mg l(-1) and 7.82 and 8.70 respectively. Nitrite nitrogen, nitrate nitrogen, chloride, phosphate phosphorus and sulphate concentrations in the water were also measured and ranged from 0.01 to 0.14, 0.01 to 0.24, 2.41 to 48.70, 0.01 to 0.12 and 54.00 to 104.40 mg l(-1) respectively Species richness (d), diversity (Shannon - Weaver, H') and evennes (J') were calculated for epipelic algae and the findings showed similar oscillations throughout the research period. Cluster analyses and multidimensional scaling (MDS) revealed a similar distribution pattern of epipelic algal flora in both lagoons.

The effect of starter culture, containing the strains Lactobacillus plantarum GM77 and Staphylococcus xylosus GM92, isolated from traditional sucuk, on the quality characteristics of dry fermented sausage (sucuk) during ripening period was studied. The microbiological (lactic acid bacteria, Micrococcus/Staphylococcus, Enterobacteriaceae) and physicochemical (pH, a(w), NPN, TBARS) properties and volatile compounds, extracted by solid phase microextraction and analyzed by gas chromatography-mass spectrometry, were determined in sucuk samples with starter culture and in the control group (without starter culture). Both starter culture and ripening period had significant effects on lactic acid bacteria, Micrococcus/Staphylococcus counts, and pH and a(w) values (P < 0.01). The highest value for nonprotein nitrogen (NPN) was observed to occur in samples with starter culture (P < 0.05). TBARS value increased during ripening, the highest value was determined at 14th day in samples with starter culture. Among volatile compounds, terpenes were the major group in sucuk. Other volatile compounds (aldehydes, ketones, sulfur compounds, acids, esters, aliphatic hydrocarbons, aromatic hydrocarbons, and alcohols) can be found in fewer amounts. While the use of starter culture was affecting a few compounds, ripening period had affected most of the compounds.

Water quality models have relatively large number of parameters, which need to be estimated against observed data through a non-trivial task that is associated with substantial difficulties. This work involves a systematic model calibration and validation study for river water quality. The model considered was composed of dynamic mass balances for eleven pollution constituents, stemming from QUAL2E water quality model by considering a river segment as a series of continuous stirred-tank reactors (CSTRs). Parameter identifiability was analyzed from the perspective of sensitivity measure and collinearity index, which indicated that 8 parameters would fall within the identifiability range. The model parameters were then estimated by an integration based optimization algorithm coupled with sequential quadratic programming. Dynamic field data consisting of major pollutant concentrations were collected from sampling stations along Yesilirmak River around the city of Amasya in Turkey, and compared with model predictions. The calibrated model responses were in good agreement with the observed river water quality data, and this indicated that the suggested procedure provided an effective means for reliable estimation of model parameters and dynamic simulation for river streams.

Biomass in the form of agricultural residues is becoming popular among new renewable energy sources, especially given its wide potential and abundant usage. Pyrolysis is the most important process among the thermal conversion processes of biomass. In this study, the various characteristics of bio-oils acquired under different pyrolysis conditions from safflower seed press cake (SPC) were identified. The elemental analyses and calorific values of the bio-oils were determined, and then the chemical compositions of the bio-oils were investigated using chromatographic and spectroscopic techniques such as column chromatography, (1)H NMR, FTIR and GC. The fuel properties of the bio-oil such as kinematic viscosity, flash point, density, water content and ASTM distillation were also determined. Chemical compositions of bio-oils showed that some quantities of hydrocarbons were present, while oxygenated and polar fractions dominated. The bio-oils obtained from safflower seed press cake were presented as an environmentally friendly feedstock candidate for biofuels and chemicals.

Lake Uluabat, known for its scenic beauty and richness of aquatic life, is situated in Marmara Region, Bursa (Turkey). On account of its importance, lake Uluabat was designated by the Ministry of Environment as a Ramsar site in 1998. Physical, chemical and microbiological parameters of the aquatic ecosystem in lake Uluabat were measured monthly at five stations from February 2003 to January 2004. The results showed that lake Uluabat can be classified as Class I with respect to temperature (16.36 +/- 7.47 degrees C), nitrate nitrogen (0.63 +/- 0.50 mgl(-1)), sodium (9.64 +/- 2.78 mgl(-1)), chloride (20.45 +/- 4.59 mgl(-1)), sulphate (54.80 +/- 29.97 mgl(-1)); as Class II with respect to dissolved oxygen (7.62 +/- 1.99 mgl(-1)), ammonium nitrogen (0.52 +/- 0.49 mgl(-1)), chemical oxygen demand (35.74 +/- 10.66 mgl(-1)), total coliform (2027 MPN100 ml(-1) (average value)); as Class III with respect to pH (8.69 +/- 0.16) and as Class IV with respect to total nitrogen (84.94 +/- 66.13 mgl(-1)), total phosphorus (1.11 +/- 3.01 mgl(-1)), biochemical oxygen demand (21.21 +/- 6.60 mgl(-1)) according to TWPCR (Turkey Water Pollution Control Regulation). The nutrient content of lake waterapparently indicated that lake had an eutrophic characteristic. Phosphorus was determined as a limiting factor in lake. The measured hardness values (140.94 +/- 14.61 CaCO3 mgl(-1)) indicated that lake water was classified as soft/hard during the study period. Eutrophic characteristic of the lake and contaminant accumulation in water will probably affect the future use of the lake. Therefore, pollution parameters must be regularly monitored and evaluated according to aquatic living and local regulations.

We investigated conventional characterization of wastewaters of the "Kullar Domestic Wastewater Treatment Plant." In the study of conventional characterization; 23 composite samples, which were taken during 10 months, were used and analysed as COD, BOD5, TKN, NH3-N, SS, VSS, TP, RP, TS, Alkalinity, oil and grease, detergent, chloride parameters. For determine of the plant efficiency, 8 output grab samples were taken. The COD and BOD5 values of influent, respectively, ranging from 37 to 1,056 mg/L and 8 to 140 mg/L in total wastewater. The meanly BOD5/COD ratio was calculated as 0.34 in total wastewaters.

This study examines the applicability of five European biotic indices and the Gammarus:Asellus ratio (G:A), compared with the measurement of physicochemical parameters, in order to determine the water quality at ten sites along the Tokat part of Cekerek stream, in Anatolia, Turkey, during the period February 2002 to January 2003. The biological and chemical results are in good agreement with respect to the water quality. In particular, the G:A ratio was calculated to be high at the first three stations and this result was correlated with the ETBI and the Chandler scores. Consequently, the water quality of Cekerek stream was classified as class I for biological and physicochemical data, except for phosphate, ammonia nitrogen, nitrate and nitrite at the last seven stations. The high concentrations of these chemicals probably result from agricultural runoff and urban sewage. In total, 55 taxa of benthic macroinvertebrates were identified from the Cekerek stream during this study period.

Tulum cheeses were manufactured from raw ewe's milk and ripened in goat's skin bags (tulums) or plastic containers to understand the effect of ripening container on the chemical composition, biochemistry, microbiology, and volatile composition of Tulum cheeses during 150 d of ripening. Chemical compositions of the cheeses ripened in tulums were significantly different and the moisture contents decreased rapidly in those cheeses because of the porous structure of the tulum. Higher microbial counts were detected in the cheeses ripened in plastic than in cheeses ripened in tulums. Differences in nitrogenous compounds and total free AA of the cheeses were not significant. Total concentrations of free AA in cheeses increased with age and Glu, Ala, Val, Leu, and Phe were the most abundant AA in the cheeses. Urea-PAGE of pH 4.6-insoluble fractions of the cheeses during ripening showed similar degradation patterns in all cheeses. Peptide profiles by reversed-phase HPLC of pH 4.6- and ethanol-soluble or ethanol-insoluble fractions of the cheeses revealed only minor differences in the concentrations of some peptides among the cheeses; however, age-related changes in peptide concentrations were significantly different among the cheeses. Cheeses were analyzed at 90 d of ripening for volatile compounds by solid-phase microextraction gas chromatography-mass spectrometry. One hundred volatile components were identified, including 11 acids, 16 esters, 12 methyl ketones, 7 aldehydes, 22 alcohols, 7 sulfur compounds, 6 terpenes, and 19 miscellaneous compounds. The main components were short-chain fatty acids, 2-butanone, diacetyl, and primary alcohols. Quantitative differences in several volatile compounds were evident among the cheeses. Cheeses ripened in tulums or plastic had similar aroma patterns, but the concentrations of some components were different.

With the aim of protecting drinking water sources in rural regions, pilot-scale subsurface water flow (SSF) and free water surface flow (FWS) constructed wetland systems were evaluated for removal efficiencies of nitrogenous pollutants in tertiary stage treated wastewaters (effluent from the Pasaköy biological nutrient removal plant). Five different hydraulic application rates and emergent (Canna, Cyperus, Typhia sp., Phragmites sp., Juncus, Poaceae, Paspalum and Iris) and floating (Pistia, Salvina and Lemna) plant species were assayed. The average annual NH4-N, NO3-N and organic-N treatment efficiencies were 81, 40 and 74% in SSFs and 76, 59 and 75% in FWSs, respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances. Nitrification, denitrification and ammonification rate constants (k20) values in SSF and FWS systems were 0.898 d-1 and 0.541 d(-1), 0.486 d(-1) and 0.502 d(-1), 0.986 d(-1) and 0.908, respectively. Results show that the first-order plug flow model clearly estimates slightly higher or lower values than observed when compared with the other model.

In the present study, effects of pH (5.0, 7.0 and 9.0) and lead (1, 5, 10, 25, 50 and 100 microg mL(-1)) were investigated on uptake of lead, content of chlorophyll and nitrogen in Nasturtium officinale and Mentha aquatica. Total chlorophyll and nitrogen contents were adversely affected from Pb2+ concentrations dose dependently at each pH. The macrophytes were adversely affected by pH 5.0 or more than 9.0. After 12-days Pb2+ treatment, results showed that lead accumulation of macrophyte tissues was variable. According to the parts of the macrophytes, Pb2+ amounts were generally found at all tested pH levels and the metal concentrations for M. aquatica in the following order: root > stem > leaf and for N. officinale root > leaf > stem. Pb2+ concentrations in plant tissues (root, stem, leaf) in relation to pH were generally found for both macrophytes in following order: 7.0 > 9.0 > 5.0. Despite of the fact that high Pb2+ accumulation was observed in root tissues of the macrophytes, low metal accumulation was measured in the above-ground parts indicating low root-leaf translocation. The study indicated that uptake rate of Pb2+ and its toxicity on Chlorophyll and nitrogen contents in the macrophytes were dependent upon pH value of solutions.

Turkish White-brined cheese was manufactured using Lactococcus strains (Lactococcus lactis ssp. lactis NCDO763 plus L. lactis ssp. cremoris SK11 and L. lactis ssp. lactis UC317 plus L. lactis ssp. cremoris HP) or without a starter culture, and ripened for 90 d. It was found that the use of starters significantly influenced the physical, chemical, biochemical, and sensory properties of the cheeses. Chemical composition, pH, and sensory properties of cheeses made with starter were not affected by the different starter bacteria. The levels of soluble nitrogen fractions and urea-PAGE of the pH 4.6-insoluble fractions were found to be significantly different at various stages of ripening. Urea-PAGE patterns of the pH 4.6-insoluble fractions of the cheeses showed that considerable degradation of alpha(s1)-casein occurred and that beta-casein was more resistant to hydrolysis. The use of a starter culture significantly influenced the levels of 12% trichloroacetic acid-soluble nitrogen, 5% phosphotungstic acid-soluble nitrogen, free amino acids, total free fatty acids, and the peptide profiles (reverse phase-HPLC) of 70% (vol/vol) ethanol-soluble and insoluble fractions of the pH 4.6-soluble fraction of the cheeses. The levels of peptides in the cheeses increased during the ripening period. Principal component and hierarchical cluster analyses of electrophoretic and chromatographic results indicated that the cheeses were significantly different in terms of their peptide profiles and they were grouped based on the use and type of starter and stage of ripening. Levels of free amino acid in the cheeses differed; Leu, Glu, Phe, Lys, and Val were the most abundant amino acids. Nitrogen fractions, total free amino acids, total free fatty acids, and the levels of peptides resolved by reverse phase-HPLC increased during ripening. No significant differences were found between the sensory properties of cheeses made using a starter, but the cheese made without starter received lower scores than the cheeses made using a starter. It was found that the cheese made with strains NCDO763 plus SK11 had the best quality during ripening. It was concluded that the use of different starter bacteria caused significant differences in the quality of the cheese, and that each starter culture contributed to proteolysis to a different degree.

A pilot study has been initiated to develop an approach for quantification of nitrogen excesses from agricultural activities that involve greenhouse farming in Kumluca Plain, Turkey. Detailed calculations utilizing the nitrogen balance method (NBM) were carried out at nine different locations within the plain over a time period of one year. The major contributing factors and governing operative mechanisms taken into consideration were nitrogen application rates both as organic and chemical fertilizers, irrigation water application practices, and nitrogen uptake by plants. The adopted approach yielded valuable information such as plant nitrogen uptake efficiencies, excess nitrogen, leaching rates and leachate nitrogen concentrations. Further, a site specific multiple linear regression model has been developed to estimate the ratio (N(leachate)/N(groundwater)) as a function of independent variables: farming age, excess nitrogen application and SEEPAGE Index Number. The negative sign of the model parameters implies that the ratio (N(leachate)/N(groundwater)) decreases as values of the independent variables increase. The adopted approach and the obtained results can beneficially be applied to similar sites to establish basic parameters of irrigation and fertilizer application operations.

The (15)N study aimed to estimate the portion of nitrogen released from tobacco-waste to be utilized by maize crop. Tobacco-waste at the levels of 0, 2, 4, 6 and 8 g pot(-1) and ((15)NH(4))(2)SO(4) as nitrogen fertilizer labelled with 5 at.% exc. at the levels of 0, 4, 8, 12 and 16 mg N pot(-1) together with a basal dressing of some nutrients were added to pots with Pioneer maize variety. After the harvest, dry matter yield was recorded and (15)N determinations and calculations were made. Tobacco-waste had a positive effect on the growth and on the nitrogen uptake of maize crop. Increasing the rates of tobacco-waste increased the dry matter yield of maize crop from 4.64 g pot(-1) (at control) to 7.22 g pot(-1) (at the tobacco-waste treatment of 8 g pot(-1)). The values of (15)N in the plant derived from nitrogenous fertilizer also increased with increasing nitrogen fertilizer levels, whereas they decreased from 0.427 % to 0.249 % with increasing tobacco-waste treatments from 0 to 8 g pot(-1), respectively. The average values of per cent nitrogen derived from nitrogenous fertilizer (Ndff) varied from 4.32 % to 7.95 % at the rates of 4-16 mg N pot(-1), respec-tively. However, Ndff decreased from 8.54 % to 4.99 % with increasing tobacco-waste treatments from 0 to 8 g pot(-1), respectively. Per cent nitrogen derived from tobacco-waste (Ndft) increased from 21.8 % to 38.5 % with increasing tobacco-waste treatments from 2 to 8 g pot(-1), respectively. The results have revealed that (15)N tracer technique was confidently used for the investigation of nitrogen levels released from tobacco-waste as organic waste to be utilized by maize crop.

Aims: To determine the effect of environmental conditions on the production of extracellular lignocellulose-degrading enzymes by Streptomyces sp. F2621 and to assess the potential use of these enzymes in the hydrolysis of lignocellulose material., Methods and Results: The production of extracellular lignocellulose-degrading enzymes, endoxylanase, endoglucanase and peroxidase during the growth of Streptomyces sp. F2621 in basal salts-yeast extract medium containing different carbon sources and the effect of a number of environmental parameters (e.g. carbon sources and concentrations, pH and temperature) were investigated. The highest endoxylanase (22.41 U ml(-1)) and peroxidase (0.58 U ml(-1)) activities were obtained after 2-4 days of incubation at 30 degrees C in a basal salts medium containing 0.4% (w/v) oat spelt xylan and 0.6% (w/v) yeast extract, corresponding to C : N ratio of 6 : 1. Cell-free extracellular enzyme preparations from the strain were capable of releasing both sugar and aromatic compounds during incubation with eucalyptus paper pulp, straw and xylan. Overall, 9.3% hydrolysis of xylan occurred after 24-h incubation. However the rates of hydrolysis of paper pulp and straw were approximately twofold less than xylan hydrolysis, although the total percentage hydrolysis of available substrate (24.5% and 16.3%, respectively) was greater than xylan hydrolysis., Conclusions: The high levels of enzyme production achieved under batch cultivation conditions, coupled with no significant production of endoglucanase during the growth phase of organism and the release of both sugar and aromatic compounds from paper pulp and straw signify the suitability for these enzymes for industrial applications such as pulp and paper production., Significance and Impact of the Study: The results highlight the environmental conditions for the production of extracellular lignocellulose-degrading enzymes by Streptomyces sp. F2621 and suggest the use of streptomycetes and/or their enzymes in industrial processes.