Geochemical fractionation and pollution assessment of Zn,Cu, and Fe in surface sediments from Shadegan Wildlife Refuge,southwest of Iran

This research focuses on the fractionation and distribution patterns of heavy metals (Zn, Cu, and Fe) in surficial sediments collected from Shadegan Wildlife Refuge, the biggest wetland in southern part of Iran, to provide an overall classification for the sources of metals in the study area using a sequential extraction method. For this purpose, a four-step sequential extraction technique was applied to define the partitioning of the metals into different geochemical phases of the sediment. The results illustrated that the average total level of Zn, Cu, and Fe in surface sediments were 55.20 ± 16.04, 22.86 ± 5.68, and 25,979.01 ± 6917.91 μg/g dw, respectively. On the average, the chemical partitioning of all metals in most stations was in the order of residual >oxidizable-organic > acid-reducible > exchangeable. In the same way, the results of calculated geochemical indices revealed that Cu, Zn, and Fe concentrations are mainly influenced by lithogenic origins. Compared with consensus-based SQGs, Cu was likely to result in occasionally harmful biological effects on the biota.

     

Thermo-chemical pretreatment of the organic fraction of municipal solid waste for improved anaerobic digestion

Journal of Material Cycles and Waste Management - The hydrolysis of organic waste in anaerobic digestion is slow and time-consuming. Pretreatment of the waste can potentially improve hydrolysis and...     

Field application of SPME as a novel tool for occupational exposure assessment with inhalational anesthetics

Occupational exposure to inhalational anesthetics occurs routinely in operating rooms. It could induce serious health hazards and diseases. This exposure assessment is a crucial step in determining risks. In this study, a pen-shaped holder for solid-phase microextraction (SPME) sampler was successfully applied as a time-weighted average sampling tool for workshift exposure assessment of operation room staff to halothane. It proved to be very convenient for use in occupational environments such as operation rooms. Samples were analyzed by a gas chromatography-mass spectrometry. The validity of the SPME method was checked in real-world conditions with Occupational Safety and Health Administration (OSHA) 103 standard method for the determination of inhalational anesthetics. A good agreement between OSHA 103 and SPME methods was obtained and results demonstrated no statistically significant differences in anesthetic concentrations determined by the two analytical methods (p?≥?0.05). It is concluded that SPME in retracted mode could successfully be applied in occupational exposure assessment purposes.     

An assessment of metal contamination risk in sediments of Hara Biosphere Reserve,southern Iran with a focus on application of pollution indicators

The aim of this study was to assess the pollution status of metals in sediments of Hara Biosphere Reserve using pollution indicators. For this purpose, sediment samples from nine locations were collected and characterized for metal content (Pb, Cr, Zn, Cu, and Fe) using the total digestion technique. Comparison of metal concentrations with that of sediment quality guidelines (SQGs) demonstrated no association with negative biological effects for Cu and Zn, while the values of Pb and Cr mainly illustrated to have association with negative biological effects. The results of the geo-accumulation index (I _geo) indicated no contamination for Cr, Cu, Zn, and Fe, while the values of Pb demonstrated to have moderate contamination based on I _geo values. The analysis of the enrichment factor (EF) showed no enrichment for Cu and Zn and minor enrichment for Pb and Cr. Similar results were also found for quantification of contamination (QoC) analysis, where the values of Cu and Zn demonstrated to have a geogenic source of contamination, while the values of Pb and Cr mainly illustrated to have an anthropogenic source of contamination. According to EF and QoC calculations, the values of Cu and Zn were derived mainly from natural processes and exposure of material from the earth’s crust, while the values for Pb and Cr were enriched by anthropogenic activities. The results of the contamination factor (C _f ⁱ ) demonstrated low contamination levels for Fe, Cr, Zn, and Cu and moderate contamination levels for Pb. The pollution load index (PLI), showing the overall contamination of metals, demonstrated moderate pollution status in the study area.     

Effect of Lignocellulosic Type on Long-Term Hygroscopic Behavior of Natural Filler/HDPE Composites

Natural filler/high density polyethylene (HDPE) injection-molded composites of flour from different lignocellulosic sources were prepared, and their long-term water absorption and thickness swelling were studied. Filler samples from wheat straw, hybrid Euro-American poplar, and loblolly pine were mixed with the matrix at 35 wt% lignocellulosics content and either zero or 2% maleic anhydride grafted polyethylene (MAPE) as compatibilizer. Results indicated water absorption of all the composites followed the kinetics of a Fickian diffusion process. The water diffusion coefficient of the composites was clearly dependent upon the lignocellulosic type. The wheat straw composites showed the highest and the pine composites exhibited the lowest water absorption coefficients. The highest thickness swelling took place in the wheat straw composites, followed by the poplar and pine composites, respectively. Adding MAPE to the composites decreased the water diffusion coefficient and thickness swelling by improving the adhesion between natural filler and the HDPE.     

Investigation of the effects of static magnetic field on apoptosis in bone marrow stem cells of rat

This research was carried out to evaluate the influence of static magnetic field on the rate of apoptosis in bone marrow stem cells (BMSCs) of rats. Extracted cells were suspended in αMEM as a culture media for 48 h. After that, cells were exposed to 15 mT static magnetic field (SMF) for 5 h, incessantly with or without FeCl₂. The rate of apoptosis was then assessed via flow cytometery. The results showed that either treatment with FeCl₂ or exposure to SMF enhanced the rate of apoptotic cells. Moreover, cells that were treated simultaneously with FeCl₂ and SMF have higher rate of apoptosis. An increase in apoptosis by 26.5% was induced by SMF alone and an increase in apoptosis by 28.2% was induced by a combination of FeCl₂ and SMF, compared to their corresponding controls. The results recommended that the effects of SMF on apoptosis may be related to increment of the number of free radicals in the cells.     

From Iran: Does Improvement in Corporate Environmental Performance Affect Corporate Risk Taking?

Superior corporate environmental performance (CEP) has become essential to the competitive advantage and financial success of businesses. However, the main reasons managers pay attention to environmental performance are improved reputation in the capital market and profitability, as well as reductions in operating costs and risks. This article describes the findings of a study that examines the relationship between CEP, using a reduction of carbon dioxide (CO₂) emissions as a measure, and corporate risk taking. In addition to indicating a significant negative relationship between CEP and firm risk, the study results also show that a 1% improvement of CEP decreases corporate risk by 3%.     

A Box-Behnken design for determining the optimum experimental condition of the fungicide (Vapam) sorption onto soil modified with perlite

In the present study, response surface methodology (RSM) based on the Box-Behnken design (BBD) was employed to investigate the effects of the different operating conditions on the removal of the fungicide (Vapam) onto soil modified with perlite using sorption process. The process parameters such as pH of the fungicide solution (2, 5 and 8), temperature (15, 25 and 35°C), shaking time (2, 13 and 24 h) and the percentage of perlite in the modified soil (0, 2 and 4 %) were investigated using a four-factor-three-level Box-Behnken design at an initial fungicide concentration of C(0) = 1.6 mg/L as a fixed input parameter. A second-order quadratic model suggested the optimum conditions to be as follows: fungicide solution pH of 3.57, temperature of 15°C, shaking time of 3.5 h and 4% of perlite in the modified soil which resulted in the improvement of Vapam sorption. Under optimum conditions, the fungicide (Vapam) removal was predicted 12.88 μg/g by BBD. The confirmatory experiments were conducted and the results revealed that the fungicide removal was 13.14 μg/g which indicated that the predicted and the observed values of response (Vapam removal) were in close agreement. Therefore, the soil modified with perlite holds good potential for Vapam sorption. This is the first report on fungicide Vapam sorption onto soil modified with perlite using statistical experimental design employing response surface methodology.