Application of zeolite-activated carbon macrocomposite for the adsorption of Acid Orange 7: isotherm, kinetic and thermodynamic studies

In this study, the adsorption behavior of azo dye Acid Orange 7 (AO7) from aqueous solution onto macrocomposite (MC) was investigated under various experimental conditions. The adsorbent, MC, which consists of a mixture of zeolite and activated carbon, was found to be effective in removing AO7. The MC were characterized by scanning electron microscopy (SEM), energy dispersive X-ray, point of zero charge, and Brunauer–Emmett–Teller surface area analysis. A series of experiments were performed via batch adsorption technique to examine the effect of the process variables, namely, contact time, initial dye concentration, and solution pH. The dye equilibrium adsorption was investigated, and the equilibrium data were fitted to Langmuir, Freundlich, and Tempkin isotherm models. The Langmuir isotherm model fits the equilibrium data better than the Freundlich isotherm model. For the kinetic study, pseudo-first-order, pseudo-second-order, and intraparticle diffusion model were used to fit the experimental data. The adsorption kinetic was found to be well described by the pseudo-second-order model. Thermodynamic analysis indicated that the adsorption process is a spontaneous and endothermic process. The SEM, Fourier transform infrared spectroscopy, ultraviolet–visible spectral and high performance liquid chromatography analysis were carried out before and after the adsorption process. For the phytotoxicity test, treated AO7 was found to be less toxic. Thus, the study indicated that MC has good potential use as an adsorbent for the removal of azo dye from aqueous solution.     

The effect of nanosilica incorporation on the mechanical properties of concrete exposed to elevated temperature: a review

Environmental Science and Pollution Research - Exposing concrete to high temperatures leads to harmful effects in its mechanical and microstructural properties, and ultimately to total failure. In...     

Impact of ginseng on neurotoxicity induced by cisplatin in rats

Environmental Science and Pollution Research - Over the years, many researches have shown the potential protective effects of ginseng for preventing and treating neurological damage and their...     

Morphometric and electrophoretic analysis of 13 populations of Anatolian black pine in Turkey

The genetic variation in populations of Anatolian black pine (Pinus nigra Arn. subsp. pallasiana (L.) Holmboe.), one of the species covering large areas in Turkey, was investigated. Open pollinated seeds were collected from 13 populations in a natural distribution range. Six characters of seeds (length, width, ratio of length to width, weight/1000 seeds) and seedling characters (cotyledon number and hypocotyls height) and two enzyme systems viz. leucine aminopeptidase (LAP) and glutamate oxaloacetate transaminase, (GOT) were investigated. Significant differences were detected among the populations for the morphological characters. In addition, isozyme patterns of two enzyme systems revealed that LAP has two loci (one with 2 alleles and the other with 3), while GOT has three loci (two with 3 alleles and the third one with 2 alleles). Polymorphic loci were 74% on the average. The mean number of alleles per loci was 1.94 and expected heterozygosity was 19%. The mean total genetic diversity was calculated as 0.203; the mean gene diversity within populations was determined as 0.188, and the average between subpopulations diversity was 0.016. The relative magnitude of genetic differentiation among subpopulations was measured as 0.074 indicating that only 7.4% of the total genetic diversity was there between populations. Average genetic distance was 0.093 according to Gregorius. Nei's genetic distance was 0.022.     

Assessment of using unleaded fuel in the harsh environment of the United Arab Emirates

The service life of lubricating oil produced in the United Arab Emirates (UAE) was examined using a car fueled with leaded or unleaded gasoline of the same grade in harsh local conditions. In addition, the economic impact of using leaded vs. unleaded gasoline via the effects on the useful life of engine oil was investigated. Every 500 km that the car was operated, the physical properties of the oil were examined to determine the optimum oil life before replacement. It was found that relative to unleaded gasoline, leaded gasoline resulted in a faster deterioration of lube oil properties and a reduced useful life of the oil. Many of the effects of use on the physical properties of oil became apparent from the beginning of its service, especially when leaded gasoline was used. Our findings indicate that the recommended useful life of oil when using leaded gasoline is 2500 km. With unleaded gasoline, deterioration of the physical properties of the lubricating oil became a concern after 3000 km. Thus with unleaded gasoline, it is recommended to have an oil change every 3500 km. These findings indicate that the decision of the UAE government to stop using lead compound additives to improve the octane number of gasoline will not only protect the environment from the harmful effects of lead compounds, but will also extend the useful life of oil. This extension will reduce the amount of used oil that is disposed of by up to 4678 tons/year. This reduction in oil use translates to a cost savings of about 23.4 million UAE Dirhams (=$6.37 million US Dollars) per year.     

Synthesis and characterisation of potassium polytitanate for photocatalytic degradation of crystal violet

Potassium titanate nanostructures were synthesised by hydrothermal treatment of TiO2 （P25） in KOH and H2O2. As-produced powders were characterised by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption methods. Longitudinally-oriented-wire-like structures with a length up to several micrometres and diameters ranging from 10 to 30 nm were obtained. Larger size fibrous nanowires resulting from the hydrotherrnal treatment showed high affinity in adsorbing crystal violet （CV）, which was mainly due to their high surface area. The photocatalytic bleaching of CV solution revealed that the wires are photoactive under ultraviolet light irradiation. Macroporous nanowires are considered as effective adsorbents of CV, capable of photocatalvtic degradation, and they can be easily separated from the solution by settling.     

Relative Abundance of Human Bocaviruses in Urban Sewage in Greater Cairo,Egypt

Human bocavirus (HBoV) is predominantly found in the respiratory tract infections and in the stool of patients with gastroenteritis symptoms. However, data on the prevalence of HBoV genotypes in environmental samples are limited. Here we addressed the prevalence of HBoV in sewage collected from three different wastewater treatment plants in Egypt. HBoV-1, HBoV-2, and HBoV-3 were detected, whereas none of the samples were positive for HBoV-4. The median concentration of HBoV in influent samples was 8.5 × 10³ GC/l for HBoV-1, 3.0 × 10⁴ GC/l for HBoV-2, and 2.5 × 10⁴ GC/l for HBoV-3. The concentration was reduced but not completely removed in the effluent samples. The median concentration in the outlet samples was 2.9 × 10³ GC/l for HBoV-1, 4.1 × 10³ GC/l for HBoV-2, and 2.1 × 10³ GC/l for HBoV-3. Moreover, no seasonality pattern of HBoVs was found. The high incidence of HBoV in sewage samples provided an evidence of its circulation in the local population. Although the role of HBoV in respiratory or gastro-intestinal infections still remains to be fully elucidated, the risk of infection via contaminated water should be taken into consideration.     

Evaluation of the effect of serum cystatin-C and ACE I/D and ACE G2350A polymorphisms on kidney function among hypertensive sewage workers

Environmental Science and Pollution Research - Cadmium (Cd) as nephrotoxicant metal exerts its potent effect mainly on renal tubules disturbing its functions. A cross-sectional study was conducted...     

The environmental impact of remittance inflows in developing countries: evidence from method of moments quantile regression

Environmental Science and Pollution Research - Despite the importance of remittance inflows as potential source of incomes for recipient households and one of main contributors to the development...