Removal of pesticides from secondary treated urban wastewater by reverse osmosis

Environmental Science and Pollution Research - The residues of pesticides that reach water resources from agricultural activities in several ways contaminate drinking water resources and threaten...     

Petroleum hydrocarbon contamination of the Southern Black Sea Shelf, Turkey

Introduction  

In this study, total petroleum hydrocarbon (TPH) contents and some aliphatic and aromatic hydrocarbon concentrations were analysed in coastal sediments of hot points collected from along the Southern Black Sea Shelf.     

Total metal levels in crayfish Astacus leptodactylus (Eschscholtz, 1823), and surface sediments in Lake Terkos, Turkey

The aim of this study was to determine the total metal accumulation (aluminium, copper, manganese, lead, cadmium and iron) in different organs and eggs of Astacus leptodactylus (Eschscholtz, 1823) and sediments total metal contents (aluminium, copper, manganese, lead, cadmium, iron, zinc, chromium, nickel) in Lake Terkos. Water and sediment samples were collected from two stations at two different depths (1 and 2 m) of Lake Terkos in May 2008. Crayfish samples were collected by trammel net at the same region. Primary hydrographic conditions, such as temperature (13.6–19.4°C), salinity (0.27–0.34‰), dissolved oxygen (7.04–12.30 mg l^???1) and pH (7.42–8.51), were recorded for each sampling point. Moreover, the total organic carbon (1.65–5.44%) and the total calcium carbonate contents (19.44–41.16%) of sediment samples were determined. According to the Turkish Food Codex (J Zool 26:283–288, 2002), the maximum allowable Pb and Cd levels in crayfish are 0.5 mg/kg wet weight. Accordingly, the Pb and Cd levels determined in A. leptodactylus samples are below this limit. However, when compared with the acceptable metal limits defined by WHO, Australian National Health and Medical Research Council and Ministry of Agriculture in United Kingdom (UK), it is clear that the Cu level is at the limit and the Cd results exceed the limit. When the metal contents in sediment samples from Lake Terkos are examined, it is seen that the Al, Fe, Mn, Ni and Cu contents are lower while Zn, Cr, Cd and Pb contents are higher than the crustal average values. The high values draw attention to the land-based domestic and industrial inputs. Lake Terkos sediments have high enrichment factors (EF) of Zn, Cr, Cd and Pb metals which corroborate this result. The low EFs of Fe, Ni and Cu are due to the natural (terrigeneous) inputs. Additionally, there is no Al, Fe, Ni and Cu metal enrichment in these lake sediments because of the low contamination factor (CF) values. However, it is moderately contaminated by Zn, Cr and Pb, and heavily contaminated by Cd.     

Modeling individual tree mortality for crimean pine plantations

Individual tree mortality model was developed for crimean pine (Pinus nigra subsp. pallasiana) plantations in Turkey. Data came from 5 year remeasurements of the permanent sample plots. The data comprises of 115 sample plots with 5029 individual trees. Parameters of the logistic equation were estimated using weighted nonlinear regression analysis. Approximately 80% of the observations were used for model development and 20% for validation. The explicatory variables in the model were ratio of diameter of the subject tree and basal area mean diameter of the sample plot as measure of competition index for individual trees, basal area and site index. All parameter estimates were found highly significant (p < 0.001) in predicting mortality model. Chi-square statistics indicate that the most important variable is d / d(q), the second most important is site index, and the third most important predictor is stand basal area. Examination of graphs of observed vs. predicted mortality rates reveals that the mortality model is well behaved and match the observed mortality rates quite well. Although the phenomenon of mortality is a stochastic, rare and irregular event, the model fit was fairly good. The logistic mortality model passed a validation test on independent data not used in parameter estimation. The key ingredient for obtaining a good mortality model is a data set that is both large and representative of the population under study and the data satisfy both requirements. The mortality model presented in this paper is considered to have an appropriate level of reliability.     

Impact of combining chlorine dioxide and chlorine on DBP formation in simulated indoor swimming pools

The main objective of this study was to assess the combined use of chlorine dioxide (ClO2) and chlorine (Cl2) on the speciation and kinetics of disinfection by-product (DBP) formation in swimming pools using synthetic pool waters prepared with a body fluid analog (BFA) and/or fresh natural water. At 1:25 (mass ratio) of ClO2 to Cl2, there was no significant reduction in the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) for both BFA solution and natural water compared to the application of Cl2 alone. When the mass ratio of ClO2 to Cl2 increased to 1:1, substantial decreases in both THMs and HAAs were observed in the natural water, while there was almost no change of DBP formations in the BFA solution. Haloacetonitriles and halonitromethanes levels in both water matrices remained similar. In the presence of bromide, the overall DBP formation increased in both BFA solution and natural water. For the DBP formation kinetics, after 72 hr of contact time, very low formation of THMs and HAAs was observed for the use of ClO2 only. Compared to Cl2 control, however, applying the 1:1 mixture of ClO2/Cl2 reduced THMs by > 60% and HAAs by > 50%. Chlorite was maintained below 1.0 mg/L, while the formation of chlorate significantly increased over the reaction time. Finally, in a bench-scale indoor pool experiment, applying ClO2 and Cl2 simultaneously produced less THMs compared to Cl2 control and kept chlorite at < 0.4 mg/L, while HAAs and chlorate accumulated over 4-week operation period.     

Toxic metal (Pb, Cd, As and Hg) and organochlorine residue levels in hake (Merluccius merluccius) from the Marmara Sea, Turkey

Toxic metals (Pb, Cd, As and Hg) and organochlorine residue levels were measured in hake (Merluccius merluccius) from the Marmara Sea. Biota samples were collected by a trawling cruise of the R/V ARAR in August and December 2009. The concentrations of toxic metals varied between Pb, 3.23-14.4; Cd, <0.01-2.14; Hg, 0.01-0.18 and As, 0.01-0.21 [Formula: see text]g g(-1) dry wt. Pb levels in the Marmara Sea were found to be higher than the critical limits set by the both Turkish Ministry of Environment for Aquatic Products (1 μg g(-1) wet wt.) and European countries (2.0 μg g(-1), UNEP 1985). In contrast, As and Hg levels were found to be lower than the critical limits for two periods. Cd contents of fish from the Marmara Sea were also comparable to or slightly lower than contents of fish from the Southern Black Sea Shelf. The results of organochlorine residues ranged between total HCH, <0.05 and 99 ng g(-1); endrin, <0.001 and 381 ng g(-1); alpha-endosulphan, <0.05 and 90 ng g(-1); beta-endosulphan, <0.05 and 15.3 ng g(-1); o,p DDE, 3.5 and 52.4 ng g(-1); p,p DDE, 7.4 and 139 ng g(-1); o,p DDD, 1.5 and 90.2 ng g(-1) and p,p DDD, 2.7 and 86 ng g(-1) wet weight. The rivers for the distribution of organochlorine levels in the Marmara Sea ordered from highest to lowest as Dil R. > Susurluk R. > Biga R. > G?nen R. The high levels of o,p and p,p DDE, and o,p and p,p DDD compounds, which are metabolites of DDT, indicate its illegal use. Toxic metal and organochlorine residue levels of fish are significantly higher than levels from the Mediterranean Sea.     

The study of heavy metal pollution and accumulation in water, sediment, and fish tissue in Kızılırmak River Basin in Turkey

The accumulation of heavy metals such as Pb, Hg, Co, Cr, Cu, Zn, and Br were determined in water, sediment, muscle, and gill of three fish species (Leuciscus cephalus, Capoeta tinca, Capoeta capoeta) which were collected in K?z?l?rmak River Basin (Delice River). The metal concentration showed a general trend of Br>Zn> Pb>Cr>Cu>Hg>Co in water and Cr>Zn>Pb> Cu>Co>Hg>Br in sediment samples while Zn> Cu>Pb>Br>Cr>Hg>Co were in muscle and Zn>Pb>Cu>Cr>Br>Hg>Co were in the gill tissue.     

Developing a Decision-Support System for Waste Management in Aluminum Production

Industrial enterprises constitute a major portion of the world’s economy, as well as a large proportion of a country’s businesses and total employment. In Turkey, industrial enterprises are underdeveloped in terms of knowledge, skill, capital, and particularly accessing and benefiting from the advantages provided by modern information and communication technologies. Aluminum manufacturing has been reported to be the largest industry in Turkey with respect to production volumes and application fields. However, aluminum production is known to be an important contributor to environmental pollution, and the relative contribution of other related enterprises to the total industrial environmental impact is unknown. Environmental pollution sources can typically be classified into three categories: gaseous emissions, solid wastes, and wastewaters. The types of wastes produced by aluminum production vary based on the process line used, the variety of target products produced, and the production capacity of a given plant. As the capacities of facilities grow, the type and amount of waste become more variable. Therefore, the primary objective of this study is to determine the priority of each waste type in aluminum manufacturing industries. This study was conducted in the Industrial Zone of Kayseri in Turkey. Three different facilities that range in size from large to small based on their production volume, plant capacity, and variety of production are selected for this study. The priority of waste types was determined by combining the AHP and PROMETHEE II multicriteria decision methods. While wastewater was categorized as having the highest priority in large facilities, solid waste was determined to be the highest priority in medium and small facilities.     

Biogeochemical cycle of arsenic and calculating the enrichment factor by using Li element

In this study, the biogeochemical cycle of arsenic in the Bosporus and the Golden Horn, which have a two-layer stratified structure, was investigated and the dominant feature in this cycle was observed to be the anthropogenic (domestic + industrial) activities. On the contrary, in the rural areas which are far from human activities, such as İğneada, the seawater–atmosphere interchange can be observed evidently in the periods covering the primary production.     

Characterization of soil erosion and its implication to forest management

Forests have traditionally been managed to maximize timber production or economic profit, completely neglecting other forest values. Nowadays, however, forests are being managed for multiple uses. The basic requirement of multiple use forestry is to identify and quantify forest values and to determine management objectives. The priorities of management objectives, however, must be decided. In this study, a model predicting the soil loss for multi objective forest management was developed. The model was based on data from remeasurement of permanent sample plots. The data were gathered from 132 sample plots. Approximately 80% of the observations were used for model development and 20% for validation. The model was designed for even aged and uneven aged forests, as well as for forests with mixed and pure species composition. The explicatory variables in the model were mean diameter and number of trees. All parameter estimates were found highly significant (p < 0.001) in predicting soil loss. The model fit and validation tests were fairly good. The soil loss model presented in this paper was considered to have an appropriate level of reliability. It can be used in the overall multi-objective forest management planning, but, it should be limited to the conditions for which the data were gathered.