Determination of heavy metals in lower Sakarya river sediments using a BCR-sequential extraction procedure

A BCR-sequential extraction procedure for the determination of extractable heavy metals was applied to sediments of various rivers and lakes. There are many rivers basins in Turkey. Sakarya River Basin is one of the most important basins, which consists of three parts: Upper, Middle and Lower Sakarya River Basins. In this study, the Lower Sakarya River was selected as the study area for sediments. The samples were collected monthly from 10 pre-determined stations through the river for 10 months time and analysed for the distribution of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn elements. The determination of extractable heavy metals in sediments was carried out by using Flame Atomic Absorption Spectrometer. The validation of the results was performed by the analysis of a BCR 701 standard reference material.     

Investigation of the effects of battery types and power management algorithms on drive cycle simulation for a range-extended electric vehicle powertrain

Fuel cell (FC) hybrid vehicle power trains are an attractive technology especially for automotive applications because of their higher efficiency and lower emissions compared to conventional vehicles. This study focuses on the design of an FC hybrid power train system and evaluation of its simulations for a given speed profile through two alternative power management algorithms (PMAs). Parameters suitable for a small vehicle were taken into consideration in the mathematical model of the vehicle. The proposed hybrid power train consists of an energy storage system, composed of a 4-kg battery pack (either lithium-ion (Li-ion) battery, nickel metal hydride, or nickel–cadmium) and a direct methanol fuel cell (DMFC) as the range extender. The PMAs basically aim to fulfill the power requirements of the vehicle and decide how to command the power split between the battery and the FC. The model comprising a DMFC, a battery, and PMAs was developed in MATLAB/Simulink environment. The polarization curve of the FC was obtained using a one-dimensional DMFC model. Vehicle power requirements for a drive cycle were calculated using the equations of longitudinal dynamics of vehicle, and the results were integrated into MATLAB/Simulink model. As a result of the simulations, methanol consumption, state of charge of the battery, and power output of the FC were compared for the PMAs. This comparison shows the effect of PMAs on the hybrid vehicle performance for three battery types. The results indicate that the vehicle range could be increased when proper strategy is used as PMA.     

Treatment of textile dyeing wastewater by biomass of Lactobacillus: Lactobacillus 12 and Lactobacillus rhamnosus

The main purpose of this study was to investigate the effectiveness of Lactobacillus 12 and Lactobacillus rhamnosus as both cells and biomasses for the removal of dye from real textile dyeing wastewater. The removal experiments were conducted according to the Box–Behnken experimental design, and the regression equations for the removal of dye were determined by the Minitab 14 program. The optimum variables were found to be 10 g/?L biomass concentration for biomasses, 3 for initial pH of the solution, and 20 °C for temperature with an observed dye removal efficiency of about 60 and 80 % with L. 12 and L. rhamnosus biomasses, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy images also showed that the biomass characteristics studied were favored by the sorption of the dye from the textile industry wastewater. Consequently, these biomasses may be considered as good biosorbents due to their effective yields and the lower cost of the removal of dyes from the effluents of the textile dyeing house.     

WEEE closed-loop supply chain network management considering the damage levels of returned products

Environmental Science and Pollution Research - Due to economic, social, and environmental concerns, managing waste electrical and electronic equipment (WEEE) has become an important research area....     

P(4-vinyl pyridine) hydrogel use for the removal of UO(2)(2+) and Th(4+) from aqueous environments

4-vinyl pyridine (4-VP) based hydrogels with 2-hydroxyethylmetacrylate (HEMA) and magnetic composites were prepared and tested for use in the removal of UO(2)(2+) and Th(4+) ions from aqueous environments. It was found that the absorption of these metal ions from aqueous environments decreased with an increase in the amount of HEMA contained within p(4-VP-co-HEMA) hydrogels between 0.498?mmol for pure p(4-VP) and 0.027?mmol for pure p(HEMA). The characterization of the hydrogels was determined by swelling experiments, FT-IR and thermal analysis. The effects of initial metal ion concentration, hydrogel amount and the temperature of the medium on absorption of the ions were investigated. Langmuir and Freundlich isotherms were constructed for the absorption of UO(2)(2+) and Th(4+). Both isotherms demonstrated that these metal ions complied with monolayer absorption kinetics.     

In vitro effects of erythromycin and florfenicol on primary cell lines of Unio crassus and Cyprinus carpio

Environmental Science and Pollution Research - The ubiquitous use of antibiotics leads exposure of these chemicals on non-target aquatic species, while the toxicity assays for these chemicals are...     

Vanadium Concentrations in Settled Outdoor Dust Particles

Atmospheric dustfall is an important aspect of urban dust studies. Vanadium is considered as the marker element of air pollution emitted from residual oil and coal combustion. In this study, vanadium levels of outdoor dust particles are determined. The studied area covers the six sites located in Adapazarí (Turkey), which represents an earthquake-hit environment. The mass deposition rate was calculated for each sampling plate over the 30-days collection periods. The deposition rates for the six places in Adapazarí ranged from 20.5 to 84.9 μg/cm²/day. The arithmetic mean deposition rate for all places was 45.3 μg/cm²/day. Total dust deposition and vanadium loadings typically increased in magnitude according to the area order: Kampus > Serdivan > Çark C. > Ozanlar > Erenler > Ye?iltepe and Kampus > Serdivan > Çark C. > Ozanlar > Erenler > Ye?iltepe, respectively. The results suggested that vanadium may be useful for assessing the level of environmental pollution.     

Effects of leachant temperature and pH on leachability of metals from fly ash. A case study: Can thermal power plant, province of Canakkale, Turkey

Lignite powered electric generation plants result in increasing environmental problems associated with gaseous emissions and the disposal of ash residues. Especially, low quality coals with high ash content cause enormous quantities of both gaseous and solid fly ash emissions. The main problem is related to the disposal of fly ash, which, in many cases, contains heavy metals. It is known that toxic trace metals may leach when fly ash is in contact with water. In this study, fly ash samples obtained from the thermal power plant in the town of Can in Turkey were investigated for leachability of metals under different acidic and temperature conditions. The experimental results show that a decrease in pH of the leachant favors the extraction of metal ions from fly ash. A significant increase in the extraction of arsenic, cadmium, chromium, zinc, lead, mercury, and selenium ions from the ash is attributed to the instability of the mineral phases. These heavy metals concentrations increase with respect to increasing acidic conditions and temperature. Peak concentrations, in general, were found at around 30°C.     

Experimental analysis of flow and turbulence in the wake of neighboring emergent vegetation patches with different densities

Environmental Fluid Mechanics - Patches of vegetation in natural water bodies grow close to each other and may affect each other’s wake pattern with significant implications on nutrient...     

Design of a hybrid ANN multi-objective whale algorithm for suspended sediment load prediction

Environmental Science and Pollution Research - There is a need to develop an accurate and reliable model for predicting suspended sediment load (SSL) because of its complexity and difficulty in...