Determination of Hydrocarbons in Mussels from the Egyptian Red Sea Coast

Mussels (Brachidontes Sp.) collected in April 2000 from the Red Sea coastal of Egypt in order to determine the contamination by hydrocarbons. The study included 11 sampling stations covering about 450 Km of the Egyptian Red Sea coast for the first time. Total concentrations of 20 aliphatics (average 0.105 ng g(-1) of wet weight) and sixteen polycyclic aromatic hydrocarbons (PAHs) (average 5452 ng g(-1) of wet weight) were generally lower in comparison with those reported for some of the published surveillance and monitoring studies of coastal areas from various regions. These results suggest that the coastal area in the Red Sea of Egypt might be considered as a relatively unpolluted.     

Effect of supplemented soybean (Glycine max L) diet and extracts on aluminum sulfate-induced genotoxicity

Aim of this study is to evaluate the protective role of Glycine max L. (soybean) against aluminum sulfate-induced genotoxicity. A diet containing 30% soybean and extracts obtained with various organic solvents were administered orally to male white Swiss mice prior to intraperitoneal injection of Al₂(SO₄)₃. Light microscopy was used for the examination of genotoxicity involving somatic cells, germ cells, and sperms. The main secondary metabolites contained in each extract were isolated and identified by chromatographic and spectral analyses. Administration of soy diet and extracts to the examined mice induced significant anti-mutagenic activity against bone marrow aberrations and spermatocyte and sperm abnormalities. At the end of this study, maximum protection was achieved using the methanolic extract (83% and 79%) followed by those obtained with chloroform (71% and 49%) and n-hexane (51% and 39%) for bone marrow aberrations and spermatocyte abnormalities, respectively. The observed activity of soybean extracts might be related to the main constituents isolated and identified. These main constituents were the isoflavone glycosides genistin and daidzin in addition to saponins (methanol extract), lignan matairesinol (chloroform extract), and β-sitosterol, unsaturated fatty acids as well as phospholipids (n-hexane extract). The results illustrated that soy extracts can be considered as alternative anti-mutagenic nutraceuticals and promising source for developing anti-mutagenic drugs.     

The future of transport-related emissions in dense urban areas: an analysis of various policy scenarios with MOLES

Environmental Economics and Policy Studies - Reducing air pollution is a major policy challenge, especially in densely populated urban areas where human exposure to emissions is considerable. This...     

Modified Sugarcane Bagasse with Tartaric Acid for Removal of Diazonium Blue from Aqueous Solutions

The present study concerns with exploring the possibility of using of tartaric acid pretreated sugarcane bagasse (SCB) for removing diazonium blue (DB) from aqueous solutions. The effect of different factors on the efficiency of the adsorbent for the DB dye removal was investigated, including initial dye concentration, contact time, SCB dosage and SCB particle size. Langmuir, Freundlich, Tempkin and D–R isothermal models have been employed to analyze the adsorption equilibrium data. It was found that the adsorption of the dye fits well with the D–R model. The adsorption kinetics was also done applying four kinetic models. The regression equation coefficients refer to fitting the data to the second-order kinetic equation for removal of the DB dye. It is probable that the rate limiting step is a chemical adsorption between the adsorbent and the dye. This chemisorption process is further confirmed from the energy value of 15.1 kJ mol^?1 deduced from the D–R isotherm.     

New Methods for the Preparation Nanosized Metal Coordination Polymers

Transition-metal coordination polymers [M(ndc)(bpy)·(H₂O)m]·xH₂O (where M = Co(II), Ni(II), Cu(II) and Zn(II), ndc = 1,4-naphthalenedicarboxylate, bpy = 4,4′-bipyridine; m = 0 or 1; x = 1 or 2) were prepared by reacting the ligands and metal ions at room temperature with the aid of microwave irradiation and sonication methods. The structure of the coordination polymers was assigned based on elemental analysis, FT-IR and electronic spectral studies, thermal analysis, scanning electron microscope and X-ray powder diffraction. Thermogravimetric analysis was also used to follow up the possible thermal decomposition steps and to calculate the thermodynamic parameters of the nano-sized metal complexes. The kinetic parameters were calculated making use of the Coats–Redfern and Horowitz–Metzger equations. All obtained results of the different technics used in our study stated the ability to synthesis the metal coordination polymers of our interest using both microwave irradiation and sonication methods.     

Biomonitoring study of heavy metals in biota and sediments in the South Eastern coast of Mediterranean sea, Egypt

Concentrations of Cd, Cu, Co, Zn, Mn and Fe were determined in biota and sediment samples collected from the Eastern Harbour and El-Mex Bay in the Mediterranean Sea, Egypt. The levels of Cu, Co, Zn, Mn and Fe in the macroalgae, Ulva lactuca, Enteromorpha compressa (green algae) and Jania rubens (red algae), recorded high concentrations except for Cd. Moreover, Fe was the most predominant metal in the seaweed. The two species of bivalves, Donax trunculus and Paphia textile, showed different amounts of metals in their tissue. The abundance of heavy metal concentrations in the mussel samples was found in the order Fe> Zn> Mn> Cu> Co> Cd and Fe> Zn> Mn> Cu> Cd> Co, respectively for the two species. The metals concentrations were generally higher compared with the previous studies in mussels from the same area. The levels of metals accumulated in the investigated fish samples, Saurida undosquamis, Siganus rivulatus, Lithognathus mormyrus and Sphyraena sphyraena, were higher than those of Marmara Sea (Turkey), for Co and Cd and lower for Cu, Zn, Mn and Fe. El-Mex Bay having the highest metals concentration in sediments as their order of abundance were Fe> Zn> Mn> Cu> Cd> Co. Nevertheless, a high variability in the metal levels occurs among the studied algae and biota and also between the investigated Harbour. A significant correlations (p < 0.05) were found for each of Zn and Fe in P. textile and of Co in D. trunculus relative to their concentrations in surficial sediments.     

Eco-Synthesis of PVA/Chitosan Hydrogels for Biomedical Application

A drug delivery system based on physically cross-linked poly vinyl alcohol (PVA)/chitosan blend hydrogels for the release of sparfloxacin antibiotic as a model for drugs was described. Eco-synthesis in current work is based on synthesizing a hydrogel without using chemical crosslinking agents like in the conventional method. In addition all materials are used are non- toxic, safe, non-carcinogenic and can be accepted by the human body without danger. The swelling behavior was tested to be dependent on pH as temperature as well as time and number of freezing thawing cycles. The physical properties of the hydrogels, such as swelling percent, dissolution percent, gel fraction and mechanical properties was assessed. The antimicrobial activity of hydrogels having different compositions was evaluated for both gram positive and gram negative bacteria. Furthermore, the release of antibiotic from hydrogels prepared using the freeze—thawed process was studied. Results obtained disclose that the swelling percent of the hydrogels is pH- dependent and increases by increasing the chitosan percent and decreases with increasing the time and number of freezing cycle. With respect to the antimicrobial activity of the prepared hydrogels, display a positive effect for both gram positive and gram negative bacteria. Freeze-thawed hydrogels could serve as drug delivery system to release sparfloxacin in acidic medium. Indeed, the release percent of sparfloxacin relies on both pH and temperature.     

Treatment of benzene and n-hexane mixtures in trickle-bed air biofilters

Trickle-bed air biofilters (TBABs) are suitable for treatment of hydrophilic volatile organic compounds, but they pose a challenge for hydrophobic compounds. Three laboratory-scale TBABs were used for the treatment of an airstream contaminated with different ratios of n-hexane and benzene mixtures. The ratios studied were 1:1, 2:1, and 1:3 n-hexane:benzene by volume. Each TBAB was operated at a pH of 4 and a temperature of 20 degrees C. The use of acidic-buffered nutrient solution was targeted for changing the microorganism consortium to fungi as the main biodegradation element. The experimental plan was designed to investigate the long-term performance of the TBABs with an emphasis on different mixture loading rates, removal efficiency with TBAB depth, volatile suspended solids, and carbon mass balance closure. n-Hexane loading rate was kept constant in the TBABs for comparison reasons and ranged from 4 to 22 g/(m3 x hr). Corresponding benzene loadings ranged from 4 to 43 g/(m3 x hr). Generally, benzene behavior in the TBAB was superior to that of n-hexane because of its higher solubility. n-Hexane showed improved performance in the 2:1 mixing ratio as compared with the other two ratios.     

Preparation of antibodies and development of an enzyme immunoassay for determination of atrazine in environmental samples

An indirect competitive enzyme-linked immunosorbent assay (ELISA) has been developed and optimized for atrazine determination in soil at different depths (0–10, 10–20, and 20–30 cm) before and after 48 h of application, corn shoot and cow milk samples collected from Dina farm, Egypt. This assay was based on a specific polyclonal antibodies (PAb) raised by immunizing New Zealand rabbits with an immunogen prepared by coupling 3-{4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine-2-yl} thiopropanoic acid to bovine serum albumin (BSA) via N-hydroxysuccinimide (NHS) active ester method. The sensitivity (estimated as IC₅₀value) was 17.5 μg mL^?1 with a detection limit of 0.1 ng mL^?1. The maximum atrazine concentration was found in soil especially in the deepest layer (325 and 890 μg kg^?1 before and after application, respectively). Atrazine concentration in corn shoot was 333.28, μg kg^?1 dry plant, while there was no detectable amount in milk. All samples screened by ELISA were validated by gas chromatography mass spectrometer procedure (GC/MS). Good correlation was achieved between the two methods (r = 0.997 for soil and 0.9814 for plant). This study demonstrates the utility and convenience of the simple, practical and cost–effective ELISA method in the laboratory for analysis of environmental samples. The method is ideal for the rapid screening of large numbers of samples in laboratories where access to GC/MS facilities, is limited or lacking.