Short-term effects of hydrogen fluoride on Nicotiana tabacum L

Data on the short-term effects of fumigation with hydrogen fluoride (HF) on the response behavior of the Nicotiana tabacum L. cv. St. Karabalar 6265 are being presented. Growth rate, fluoride accumulation in leaves and soils, and degradation in chlorophyll and nicotine contents of the plant species against the variations in two experimental factors, namely the exposure concentration and exposure time parameters, were investigated. Resulting data reveals that the variety selected for this study is not so tolerant to fluoride as generally reported in the literature, if only the individual effects of the pollutant is considered.     

Characterization of Sulfate Reducing Bacteria Isolated from Cooling Towers

In this study, the occurrence and metabolic capacities of sulfate reducing bacteria (SRB) were studied in 36 water samples taken from cooling towers of 30 different buildings, such as hotels and business centres in Istanbul. SRB were present in 14 cooling towers out of 30 (46.6%) buildings and while the lowest concentration of SRB was 10 cells/mL, the highest concentration was determined as 10⁴ cells/mL. After the distribution of SRB within cooling towers was determined, several strains of SRB were isolated and characterized metabolically. The isolated strains were composed of vibroid cells, growing anaerobically by using sulfate as electron acceptor and lactate or pyruvate as electron donor. They could be related to the genus Desulfovibrio. In addition, the recorded temperature of water samples was between 12 and 33C and a significant relationship between the number of SRB and the water temperatures was not found.     

Effect of topography on sulfate redistribution in cumulonimbus cloud development

An aqueous chemical module is created and included into a complex three-dimensional atmospheric cloud-resolving mesoscale model. In the chemical module, oxidation of S(IV) by ozone and hydrogen peroxide in cloud-water and rainwater, as important process of the sulfate production is included. To examine the impact of topography on the sulfate redistribution in a clean and a polluted environment, the complex topography of Serbia is included in the model. Numerical simulations of an isolated summer Cumulonimbus cloud shows that thunderstorms generate very strong vertical sulfate redistribution from the planetary boundary layer to the upper troposphere. This redistribution is sensitive to cloud dynamics, while cloud microphysics and precipitation determine wet removal of the chemical species. In simulations with realistic topography, the chemical species are transported over larger distances close to the surface, while in the upper atmosphere, there is no difference compared to the simulations without topography. The sensitivity tests of cloud chemistry to the physical processes are made. Omission of nucleation and impact scavenging of aerosols in the model simulations shows that 75.8 and 62.5 % of total sulfur mass deposited in the base experiment for the clean and the polluted environment, respectively, is the result of other processes. Exclusion of oxidation accounted for 19.2 and 37.7 % of total sulfur deposited for clean and polluted environment. Ignoring the ice phase almost not change mass of deposited sulfur: there is an increase of 2.9 and 1.5 % for clean and polluted atmosphere, respectively. Real topography conditions affect the sulfate redistribution in the sense of greater possibilities of transport. Numerical simulations without real topography give an artificial increase of deposited sulfur mass of about 25?30 %.     

Biomonitoring of heavy metals in fish from the Danube River

The Croatian part of the Danube River extends over 188 km and comprises 58 % of the country’s overall area used for commercial freshwater fishing. To date, the heavy metal contamination of fish in the Croatian part of the Danube has not been studied. The main purpose of this study was to determine heavy metal levels in muscle tissue of sampled fish species and to analyze the measured values according to feeding habits of particular groups. Lead ranged from 0.015 μg^?1 dry weight in planktivorous to 0.039 μg^?1 dry weight in herbivorous fish, cadmium from 0.013 μg^?1 dry weight in herbivorous to 0.018 μg^?1 dry weight in piscivorous fish, mercury from 0.191 μg^?1 dry weight in omnivorous to 0.441 μg^?1 dry weight in planktivorous fish and arsenic from 0.018 μg^?1 dry weight in planktivorous to 0.039 μg^?1 dry weight in omnivorous fish. Among the analyzed metals in muscle tissue of sampled fish, only mercury exceeded the maximal level (0.5 mg kg^?1) permitted according to the national and EU regulations determining maximum levels for certain contaminants in foodstuffs, indicating a hazard for consumers of fish from the Danube River.     

Evaluation of surface water quality characteristics by using multivariate statistical techniques: A case study of the Euphrates river basin, Turkey

The surface water quality of the Euphrates river basin in Turkey are evaluated by using the multivariate statistical techniques known as factor analysis (FA) and multidimensional scaling (MDS) analysis. When FA was applied to the water quality data obtained from the 15 different surface water quality monitoring stations, two factors were identified, which were responsible from the 86.02% of the total variance of the water quality in the Euphrates river basin. The first factor called the urban land use factor explained 44.20% of the total variance and the second factor called the agricultural use factor explained 41.81% of the total variance. MDS technique showed that electrical conductivity (EC), percent sodium (Na%) and total salt are the most important variables causing difference in the water quality analysis.     

Heavy metal concentrations in two barb, Barbus xanthopterus and Barbus rajanorum mystaceus from Atatürk Dam Lake, Turkey

Concentration of some heavy metals (Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn) were determined in muscle, liver, kidney and gill of two barb, Barbus xanthopterus and Barbus rajanorum mystaceus, which have great economic values, in the Atatürk Dam Lake (Turkey). Heavy metal levels in fish samples were analyzed by inductively coupled plasma spectroscopy (ICP/OES). Heavy metal concentrations vary significantly, depending on the type of the tissue in fish species. The metal accumulation in the liver, kidney and gill of Barbus xanthopterus and Barbus rajanorum mystaceus was found to be quite high in comparison with that in the muscle. The mean concentrations of heavy metals in muscle tissues of Barbus xanthopterus were as follows: Co, 0.09; Cr, 0.12; Cu, 0.27; Fe, 5.26; Mn, 0.20; Ni, 0.08; Pb, 0.68; Zn, 1.39, whereas in muscle tissues of Barbus rajanorum mystaceus were as follows: Co, 0.11; Cr, 0.10; Cu, 1.07; Fe, 3.97; Mn, 019; Ni, 0.04; Pb, 0.66; Zn, 1.70 microg/g wet weight. Cd levels in gill and muscle tissues were below detection limits. All metal levels detected in tissues were safe for human consumption and within the limits for fish proposed by FAO/ WHO, EU and Turkish Food Codes.     

Assessment of surface water quality using multivariate statistical techniques: a case study of Behrimaz Stream, Turkey

Multivariate statistical techniques, such as cluster analysis (CA), principal component analysis, and factor analysis, were applied for the evaluation of temporal/spatial variations and for the interpretation of a water quality data set of the Behrimaz Stream, obtained during 1 year of monitoring of 20 parameters at four different sites. Hierarchical CA grouped 12 months into two periods (the first and second periods) and classified four monitoring sites into two groups (group A and group B), i.e., relatively less polluted (LP) and medium polluted (MP) sites, based on similarities of water quality characteristics. Factor analysis/principal component analysis, applied to the data sets of the two different groups obtained from cluster analysis, resulted in five latent factors amounting to 88.32% and 88.93% of the total variance in water quality data sets of LP and MP areas, respectively. Varifactors obtained from factor analysis indicate that the parameters responsible for water quality variations are mainly related to discharge, temperature, and soluble minerals (natural) and nutrients (nonpoint sources: agricultural activities) in relatively less polluted areas; and organic pollution (point source: domestic wastewater) and nutrients (nonpoint sources: agricultural activities and surface runoff from villages) in medium polluted areas in the basin. Thus, this study illustrates the utility of multivariate statistical techniques for analysis and interpretation of data sets and, in water quality assessment, identification of pollution sources/factors and understanding temporal/spatial variations in water quality for effective stream water quality management.     

Risk assessment of distribution coefficient from 137Cs measurements

Classically distribution coefficient is defined as the ratio of solid total element concentration to surface water total concentration. This coefficient is obtained from the ion measurements in the Keban Dam, Turkey, which supplies water for domestic, irrigation and hydroelectric energy generation purposes. The measurements of 137Cs are carried out in 40 different sites and the general risk formulation and application is achieved for the distribution coefficient. The models are of exponential type and the spatial independence of the data is considered. Various charts are prepared for a set of risk levels as 5%, 10%, 20%, 25%, and 50%.     

Advanced oxidation treatment of physico-chemically pre-treated olive mill industry effluent

In this study, the applicability of physico-chemical methods was investigated for the pre-treatment of the olive mill effluents prior to the discharge into the common sewerage ending with a municipal wastewater treatment plant. The samples were taken from an olive oil industry operated as three-phase process located in Turkey. Various pre-treatment methods including acid craking, polyelectrolyte and lime additions were applied. Advanced oxidation study using Fenton's process was also investigated following pre-treatment by acid cracking and cationic polyelectrolyte. Acid cracking alone gave satisfactory treatment efficiencies and polyelectrolite additions to the acid-cracked samples enhanced treatment efficiency. Since a complete treatment plant is available at the end of the sewer system, results indicated that the effluents of the investigated industry could be discharged into the municipal sewerage in the case of total chemical oxygen demand (COD_tot), suspended solid (SS) and volatile suspended solid (VSS) concentrations according to the Turkish Water Pollution Control Regulation after pre-treatment with 5 ppm anionic polyelectrolyte following acid cracking. The minimum COD_tot, SS and VSS removals were observed when raw wastewater was pre-treated with lime and the discharge standards to the municipal sewer system could not be met. Advanced oxidation with Fenton's process was applied after acid cracking and cationic polyelectrolyte treatment in order to investigate further reduction in chemical oxygen demand (COD) concentration for minimizing the influence of this industrial discharge on the existing municipal wastewater treatment plant. Results indicated that COD_tot removal increased up to 89% from 74% after Fenton's oxidation for the acid cracked samples in which cationic polyelectrolite (10 ppm) was added.     

PAC混凝沉降法处理陶瓷废水操作条件的优化

采用PAC混凝沉降法对陶瓷废水进行处理,考察PAC用量、搅拌强度、搅拌时间、进水pH和沉降时间对处理效果的影响,获得优化的操作条件。实验表明:水样的脱色率、浊度去除率和悬浮物去除率随着PAC用量、搅拌强度、搅拌时间和沉降时间的增大和进水pH的降低而呈现增大的趋势;最佳操作条件为:当废水量小、处理时间充足时,选用PAC用量为12 mg/L、搅拌强度为中速、搅拌时间为10 min、进水pH为6、沉降时间为2 h,此条件下水样的脱色率、浊度去除率和悬浮物去除率分别达到95.6%、95.7%和85.6%;当废水量大、处理时间不充足时,选用PAC用量为60 mg/L,沉降时间为30 min,此条件下水样的脱色率、浊度去除率和悬浮物去除率分别达到94.1%、93.4%和84.4%。证明混凝法对于去除陶瓷废水中的悬浮与胶体颗粒均是有效的。