The treatment of textile wastewater including chromium(VI) and reactive dye by sulfate-reducing bacterial enrichment

Sulfate-reducing bacteria (SRB) that could grow on modified Postgate C medium (PC) containing chromium(VI) were isolated from industrial wastewaters and their chromium(VI) reduction capacities were investigated as a function of changes in the initial pH values, chromium, sulfate, NaCl and reactive dye concentrations. The optimum pH value at 50 mg l(-1) initial chromium(VI) concentration was determined to be 8. Chromium(VI) reduction by SRB was investigated at 22.7-98.4 mg l(-1) initial chromium(VI) concentrations. At the end of the experiments, the mixed cultures of SRB were found to reduce within 2-6 days more than 99% of the initial chromium(VI) levels, which ranged from 22.7 to 74.9 mg l(-1). The effects of the initial 0-9.0 g l(-1) concentrations of disodium sulfate and 0-6% (w/v) concentrations of NaCI to chromium reduction showed that the lowest concentrations of sulfate and NaCI were the best for chromium reduction in the PC medium including 50 mg l(-1) chromium(VI). Chromium(VI) reduction in 50 mg l(-1) and 25-100 mg l(-1) Remazol Blue, Reactive Black B or Reactive Red RB containing media were also investigated. In the experiments, 25-30% of the initial dye concentrations and 95% of the chromium(VI) was removed from the medium at the end of 72-h and 24-h incubation periods, respectively.     

Inventory of emissions of primary air pollutants in the city of Kocaeli, Turkey

This study aims to obtain a reliable inventory of the emission rates of the principal air pollutants including PM, SO2, NOx) and CO in Kocaeli, Turkey. In the first stage, the pollutant sources classified as point, area and line sources are determined in the area. Then the annual emission rates of the pollutants released from these sources are estimated by the emission factors given by USEPA and CORINAIR. Results show that the annual emission rates for PM, SO2, NOx) and CO are 2195 tons, 5342 tons, 14632 tons and 23095 tons, respectively. On the other hand, the pollutant group with the highest contribution to total emission rate is determined as the point sources for NOx, which is responsible for 73% of total NOx emission, while it is the area sources for PM, SO2 and CO with the contribution percentages of 75, 76 and 69, respectively.     

Monitoring and assessment of land use status by GIS

The objectives of this study were to assess land suitability andto monitor the spatial and temporal changes in land use types (LUTs)by using GIS. The study was conducted in an irrigated area of 920ha, located in the East Mediterranean region of Turkey. Archiveddata of LUTs were utilized. Data analysis was conducted by usingArcInfo and ArcView GIS softwares. The land characteristics werecompared with land requirements of present LUTs by taking intoaccount the land evaluation results. Three major soil series andtwelve different LUTs were identified. Corn and citrus were themost planted LUTs in the assessment period. Generated mapsdemonstrated how LUTs changed spatially and temporally. Most LUTswere clustered in certain areas indicating that farmer'sselection of LUTs was affected by their habits and neighbor'sbehavior. Land suitability assessment results indicated thatCanakci and Mursel soil series were found to be highly suitable forall LUTs while Arikli soil series was determined to be moderately suitablecitrus, vegetables and watermelon. Citrus plantationmaps overlaid on soil series maps demonstrated that the citrushas not been planted completely on suitable areas. Landsuitability assessment showed that citrus plantation in Arikliseries would result in 40% yield loss and 58% of land is notused at its potential.     

An investigation of halogens in Izmit hazardous and clinical waste incinerator

In the combustion facilities, halogens (Cl, F, Br, I) should be considered with regard to the control of the compounds such as polychlorinated dibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF), halogenated polyaromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and volatile heavy metals formed as a result of incomplete combustion and caused adverse environmental effects. In this study halogens were observed in Izmit Hazardous and Clinical Waste Incinerator (IZAYDAS). Halogen contents of the combustion menu, flue gas, fly ash, bottom ash and filter cake were measured and their distributions in these exit streams were determined. Results showed that the major part of the halogens was partitioned to solid residues, i.e., bottom ash and filter cake which represents the removal by wet scrubbers. Fly ash and flue gas fractions of halogens were much lower due to the reduced formation of volatile compounds.     

Electrocoagulation of some reactive dyes: a statistical investigation of some electrochemical variables

In this study, the decolorization of strong colored solutions containing the reactive textile dyes by electrocoagulation was investigated. The experiments were statistically designed and carried out according to a 2(4) full factorial design with two replicate and four center points. This design was extended with eight additional axial points. Then, the non-linear regression was applied on the data by using MINITAB software. The variables chosen for this work are mixing rate, cell voltage, electrolysis time and current density. Results showed that the effective variables on decolorization process are cell voltage, electrolysis time and current density. In addition, to determine the effect of dye and electrode type on decolorization, the additional experiments were carried out. It was determined the dye and electrode type are important on the decolorization process.     

Soil concentrations and source apportionment of polybrominated diphenyl ethers (PBDEs) and trace elements around a heavily industrialized area in Kocaeli,Turkey

Air pollutants are transported by dry deposition, wet deposition, and gas exchange accumulated in soil. Therefore, soil is an important environmental medium reflecting the level and the spatial distribution of air pollutants such as polybrominated diphenyl ethers (PBDEs) and heavy metals. Soil concentrations of seven PBDE congeners and 21 trace elements were determined in a heavily industrialized region (Dilovasi) in Kocaeli, Turkey. At all sites, Σ₇PBDE concentrations ranged from 0.70 to 203 with a mean value of 26.3 μg kg^?1 (dry weight). The congener profiles and mass inventories of PBDEs and their interactions with soil organic matter (SOM) were also investigated. BDE-209 was the dominant congener at all sites, followed by BDE-99 and/or -47. The estimated inventory of PBDEs for the Dilovasi district was 310 kg. However, there are several additional industrial regions in Kocaeli city. Considering the total land area, the potential inventory would be much larger for this city. The relationship between the PBDE concentrations in soil and SOM content indicated that factors other than soil properties have a greater influence on soil concentrations. Crustal enrichment factors (EFs) were determined; correlation analysis and factor analysis (FA) were also applied to generated data set to identify and apportion the sources polluting the soil. Sn, Mn, Ca, As, Zn, Pb, and Cd had significantly high average EF values, indicating that their soil concentrations were mainly influenced by anthropogenic activities. In FA, six factors were extracted with a cumulative variance of 84.4 % and industrial activities and traffic were found to be the main factors affecting the soil profile.     

Application of artificial neural networks to predict the heavy metal contamination in the Bartin River

Environmental Science and Pollution Research - In this study, copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), nickel (Ni), and lead (Pb) analyses were performed, and the results were modelled by...     

Bioclimatic characteristic of oak species Quercus macranthera subsp. syspirensis and Quercus petraea subsp. pinnatiloba in Turkey

This study was carried out to determine some bioclimatic characteristics such as humidity category (Q2), winter variant (m), the length of the dry season (LDS) and the dry season water deficit (DSWD) of naturally growing two endemic oak taxa, Quercus macranthera subsp. syspirensis and Q. petraea subsp. pinnatiloba, living in Turkey. Our findings showed that bioclimatic tolerance range of Q. macranthera subsp. syspirensis possess 7 different types of Mediterranean bioclimate while Q. petraea subsp. pinnatiloba had 8 of them. Although Q. macranthera subsp. syspirensis was ranging among the semiarid, freezing and very cold, Q. petraea subsp. pinnatiloba was among sub-humid, freezing and very cold ambient. It was briefly established that Q. macranthera subsp. syspirensis prefers semi-arid and very cold/freezing conditions and Q. petraea subsp. pinnatiloba prefers sub-humid and cold/very cold climatic conditions.     

Does agriculture-induced environmental Kuznets curve exist in developing countries?

Even though the economic growth and the increased agricultural production bring welfare increment, they could also load significant environmental costs to society. This study aims to investigate the existence of agriculture-induced EKC hypothesis in 47 developing countries during 1976–2017 by using dynamic panel data estimators. According to the long-run findings of the DOLS and the FMOLS estimators, there is an inverted U-shaped relationship that exists between income and the CO₂ emissions, while agricultural production has a negative impact on environmental quality. In addition, the PMG estimator is also employed for robustness check. Likewise the DOLS and the FMOLS findings, the long-run results of the PMG estimator also support the existence of agriculture-induced EKC for developing countries. The empirical findings of this study provide stimulus results of policy makers to re-consider their current production infrastructure of agricultural sector to achieve sustainable development.