Gross alpha and beta radioactivity concentration in water, soil and sediment of the Bendimahi River and Van Lake (Turkey)

The concentrations of the natural radioactivity in water, soil and sediment samples collected from Bendimahi River which originates near the Tendürek Mountain (Van, Turkey), its tributaries and Van Lake (Turkey) were measured. The gross-alpha and gross-beta radioactivity concentrations were investigated in May and August in 2005. Determination of the gross-alpha and gross-beta radioactivity of river water, soil and sediment samples was obtained by using gas-flow proportional counter, PIC-MPC 9604-alpha/beta counter. In water samples, the obtained results show that in May; gross-alpha and gross-beta activity concentrations varied between 0.063-0.782 and 0.021-0.816 Bq l(-1) and in August the values were 0.009-0.037 and 0.081-3.116 Bq l(-1), respectively. The gross-alpha and gross-beta activity concentrations in soil samples ranged from 0.800 to 4.277 Bq g(-1) and 0.951 to 11.773 Bq g(-1) in May and 0.686 to 4.713 Bq g(-1) and 0.073 to 9.524 Bq g(-1) in August, respectively. Concentrations ranging from 0.782 to 4.596 Bq g(-1) and from 0.482 to 10.372 Bq g(-1) in May and from 0.580 to 5.824 Bq g(-1) and from 0.303 to 9.702 Bq g(-1) in August for gross-alpha and gross-beta radioactivity were observed in sediments, respectively.     

A simple extraction procedure for determination of total mercury in crude oil

The determination of mercury in crude oil and petroleum products is particularly difficult due to the volatile nature of both mercury and the matrix, which may lead to significant loss of the analyte. A simple extraction method for total mercury has been developed to determine total mercury in crude oil using cold vapor atomic fluorescence spectrometry. The homogenized crude oil sample was diluted to 5, 10, and 20 % (w/w) in toluene. The diluted crude oil samples were spiked with 10 and 40 μg/kg (w/w). The samples were extracted using an oxidant/acid solution, BrCl/HCl. The mercury was extracted into the aqueous phase; the ionic mercury was then reduced to volatile elemental mercury (Hg⁰) by stannous chloride (SnCl₂). The mercury vapor was detected by Merlin cold vapor atomic fluorescence spectrometry at a 253.7-nm wavelength. The average recoveries for mercury in spiked diluted crude oil (10 and 40 μg/kg, w/w) were between 96 and 103 %, respectively, in 5 and 10 % spiked diluted crude oil. Whereas, low recoveries (<50 %) were recorded in 20 % diluted spiked crude oil. The method detection limit was calculated as t _{(0.01)(n ? 1)}?×?SD where t is the student's value for 99 % confidence level and standard deviation estimate with n???1 degrees of freedom. The method detection limit was found to be 0.38 μg/kg based on 5 g of diluted crude oil sample. The method is sensitive enough to determine low levels of mercury in crude oil.     

Impact of environmental production conditions on productivity and efficiency: a case study of wheat farmers in Bangladesh

Environmental conditions significantly affect production, but are often ignored in studies analysing productivity and efficiency leading to biased results. In this study, we examine the influence of selected environmental factors on productivity and efficiency in wheat farming in Bangladesh. Results reveal that environmental production conditions significantly affect the parameters of the production function and technical efficiency, as well as correlates of inefficiency. Controlling for environmental production conditions improves technical efficiency by 4 points (p<0.01) from 86% to 90%. Large farms are more efficient relative to small and medium sized farms (p<0.01 and 0.05), with no variation among regions. Policy implications include soil fertility improvement through soil conservation and crop rotation, improvement in managerial practices through extension services and adoption of modern technologies, promotion of education, strengthening the research-extension link, and development of new varieties that have higher yield potential and are also suitable for marginal areas.     

Effects of environmental hypercapnia on hemato-immunological parameters,carbonic anhydrase,and Na+, K+-ATPase enzyme activities in rainbow trout (Oncorhynchus mykiss) tissues

In this study, the effects of environmental hypercapnia on hemato-immunological parameters and the activities of respiratory enzymes such as carbonic anhydrase (CA) and Na⁺, K⁺-ATPase were investigated in rainbow trout (Oncorhynchus mykiss) tissues (gill, liver and kidney). Batches of 12 fish were exposed to 4.5 mg L^?1 (control) and 14 mg L^?1 CO₂. No mortalities occurred during the 14 days of the experimental period. Red blood cell (RBC), hemoglobin (Hb), and hematocrit (Ht) levels, and innate immune parameters such as nitro blue tetrazolium (NBT), lysozyme, and myeloperoxidase activities, and the melano-macrophage frequency were negatively affected by elevated CO₂ levels. Patterns of change in CA activity differed among the gill, liver, and kidney. Compared with the activities of CA in the control group, the CA enzyme was significantly stimulated at day 7 in the gill tissue, whereas it was stimulated at day 14 of the experiment in the liver tissue of fish exposed to 14 mg L^?1 CO₂ (P < 0.05). In contrast to the pattern of CA enzyme activities, the Na⁺, K⁺-ATPase enzymes were stimulated significantly in the liver after day 7 but inhibited in the kidney and gill (P < 0.05). These results suggest that a subchronic exposure to hypercapnia of rainbow trout tissues may lead to adaptive changes in the respiratory enzymes and negatively affects hemato-immunological parameters.     

Two novel sets of UiO-66@ metal oxide/graphene oxide Z-scheme heterojunction: Insight into tetracycline and malathion photodegradation

Nowadays,widespread researches have been focused on the development of effective photocatalysts to remove pollutants of the aquatic system.In accordance with the universal studies,two new sets of UiO-66@metal oxide(including ZnO and TiO₂)/graphene oxide heterojunctions were synthesized for photodegradation of aromatic(tetracycline)and nonaromatic(malathion) pollutants which are challenging cases in the environment.The dosage of the photocatalyst,pH of the solution,the type of metal ox...     

Geopolymer concrete with metakaolin for sustainability: a comprehensive review on raw material’s properties,synthesis, performance,and potential application

Environmental Science and Pollution Research - In the last three decades, the gigantic demand for sustainable and environmentally friendly concrete with reduced environmental footprints has...     

Air pollution and hospitalization in megacities: empirical evidence from Pakistan

Environmental Science and Pollution Research - Air pollution has become a threat to human health in urban settlements, ultimately leading to negative impacts on overall economic system as well....     

A comparative decision-making model for sustainable end-of-life vehicle management alternative selection using AHP and extent analysis method on fuzzy AHP

Environmental protection and sustainable development are getting increasing attention in the automobile industries. Environmental consciousness has increased, and sustainability has become an important requirement for the management of end-of-life vehicles (ELVs). The proper management of ELVs can bring improved sustainability performance for any society or organisation. There are several alternative options for ELVs management such as reuse, repair, reconditioning, remanufacturing and recycling. Environmental legislation is forcing original equipment manufacturers (OEMs) to manage their products at the end of their life cycle to reduce their potential environmental impact. An appropriate selection model for sustainable ELV management alternatives in the dynamic, competitive and regulatory environment can enable a firm to satisfy economic, environmental, social and technological requirements. This study proposes an integrated model to select the dimensions and criteria for evaluating sustainable alternatives for the proper management of ELVs. First, the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method is used to select the most important dimensions and criteria for sustainable alternative selection. Next, a hierarchy has been constructed to develop a systematic technique to solve the alternatives selection problem. An analytic hierarchy process (AHP) and extent analysis method on the fuzzy AHP (FEAHP) model have been used based on the hierarchy to evaluate the most suitable alternatives from the sustainability point of view. The strength of the proposed model is that it compares the results of both methods, the imprecision of experts’ opinions is considered in the evaluation process and the model is easy to use.     

Seasonal variations of chlorophyll-a in Demirdöven Dam Reservoir (Erzurum, Turkey) in relation to phytoplankton density and environmental factors

The seasonal variations of Chlorophyll-a was examined in relation to phytoplankton density and physico-chemical factors in Demird?ven Dam Reservoir during 2000-2001. Chlorophyll-a concentrations ranged from 0.62 to 7.19 mg/m3 and from 0.67 to 8.88 mg/m3 in 2000 and 2001, respectively. Maximum Chlorophyll-a concentrations were found near the metalimnion and decreased with depth. Chlorophyll-a concentrations showed positive correlation to phytoplankton density, water temperature and nutrient concentrations, and negative correlations to Secchi depth. Demird?ven Dam Reservoir can be classified as a mesotrophic reservoir according to Chlorophyll-a concentrations.     

Artisan fishers’ perception of climate change and disasters in coastal Bangladesh

Climate change is affecting fishing communities across Bangladesh. While work has been undertaken to investigate the nature of these impacts, understanding how fishers perceive climate change at a local level, especially within developing countries, is crucial. This paper presents the results of a three-year study of the contextual determinants and dimensions of artisanal fishing community perceptions about climate change in coastal Bangladesh. Results of this study indicate that geographic characteristics, socio-economic status, worldviews, tradition, observations and disaster experiences are important determinants for shaping fishers’ perceptions about climate change. Fishers also demonstrate a long-standing tradition of risk adaptation strategies, but do not link them to climate change. We argue that these perceptions provide ideas for how to form appropriate climate responses at local levels not only in Bangladesh but other developing countries.