Efficacy of Cr-doped ZnO nanoparticles in removal of reactive black 5 dye from aqueous solutions in presence of solar radiation

Background and purpose: Dyes from textile industry are amongst the major pollutants of the environment that are harmful for both human health and the environment. Azo dyes constitute the largest and the most important class of commercial dyes, accounting for 50 of all commercial dyes. This study investigated the efficacy of Cr-doped ZnO nanoparticles in removal of reactive black 5 (RB5) dye from aquatic solutions in presence of solar radiation. Materials and methods: An experimental laboratory study was done by designing the surface-answer test. Cr-doped ZnO nanoparticles were synthesized using co-precipitation method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for characterization of the nanoparticles prepared. Effects of parameters such as pH, nanoparticle dosage, initial RB5 concentration, and contact time on the removal efficiency of RB5 were studied. The remaining concentration of RB5 was analyzed by UV/VIS spectrophotometer at a wavelength of 597 nm. Finally, the statistical analysis of the model was conducted by ANOVA. Results: Results showed that removal efficiency increased by increasing nanoparticle dosage and contact time. Also, we found that removal efficiency decreased by increasing the initial dye concentration and pH. The optimum condition for dye removal was obtained at pH 4, nanoparticle dosage of 1.75 g/L, initial dye content of 112.5 mg/L, and 75 min contact time. In this condition the efficiency removal and desirability were 75.41 and of 0.905, respectively. Conclusion: Removal of textile dyes was found to be quick and effective when using Cr-doped ZnO nanoparticles. Also, designing and performing the experiment (in low frequency) can help in optimizing the efficiency removal of pollutant from aqueous media. © 2016, Mazandaran University of Medical Sciences. All rights reserved

Arsenic in soil, vegetation and water of a contaminated region

Arsenic concentrations of surface waters, soils and plants were surveyed in three contaminated villages of Bijar County. Total arsenic in water samples (4.5 to 280 μg/L) was correlated with electrical conductivity, total dissolved solid, total hardness, alkalinity, chloride, sulphate, bicarbonate, calcium and sodium (p<0.001). Total arsenic in the soils ranged from 105.4 to 1500 mg/kg. Some of the soil factors play an important role in soil arsenic content and its bioavailability for organisms. In general, the arsenic concentrations in plants were low, especially in the most common wild species. Among 13 plant species, the highest mean arsenic concentration was found in leaves of Mentha Longifolia (79.4 mg/kg). Arsenic levels in soils and plants were positively correlated, while the ability of the plants to accumulate the element, expressed by their biological accumulation coefficients and arsenic transfer factors, was independent of the soil arsenic concentration. Relationships between the arsenic concentrations in plants, soils and surface water and the environmental aspects of these relationships have been discussed in comparison with literature data. The accumulation of arsenic in environmental samples (soil, sediment, water, plant, etc.) pose a potential risk to human health due to the transfer of this element in aquatic media, their uptake by plants and subsequent introduction into the food chain

Survey on electric and magnetic fields hp and Lenovo laptops in the vicinity of internet-connected smart phones

Nowadays exposure to electromagnetic fields, emitted from electronic devices, especially laptops and mobile phones is inevitable due to their portability. Exposure to electromagnetic fields causes harmful effects on human health. Today, most people are exposed to these fields while using their mobiles or laptops. In this cross-sectional study, the electric and magnetic fields of HP and Lenovo laptops are measured in the vicinity of 3G internet-connected Samsung smart phones at a distance of 30 and 45 cm in front of laptops. The mean electric field in the vicinity of the smartphone at a distance of 30 cm for HP and Lenovo laptops was 0.11v/m and 0.06 v/m and the mean magnetic field was 1.69 mG and 1.43 mG, respectively. The domain of electric and magnetic fields were ND-0.17 v/m and 0.3-2.4 mG, respectively. The mean electric field for HP and Lenovo laptops in the vicinity of the smartphone, at a distance of 45 cm, was 0.10 v/m and 0.06 v/m, respectively and the mean magnetic field was 1.32 mG and 1.16 mG. The mean of SAR, for HP and Lenovo laptops, in the vicinity of mobile phones, at a distance of 30 cm was 19×10-6w/kgand 5×10-6w/kg and at a distance of45 cm, was 17×10-6w/kgand 5×10-6w/kg. The Electric and magnetic field as well as SAR were less than standard. HP laptops magnetic field was significantly more than the Lenovo laptops. Unlike Lenovo laptops, electric and magnetic fields of HP laptops, in the vicinity of mobile phones, was significantly higher than the absence of mobile phones. Putting the internet-connected smart phones in the vicinity of HP laptops (significantly) and Lenovo laptops (insignificantly) increases the of electric and magnetic fields. © 2016, International Journal of Pharmacy and Technology. All rights reserved

Optimization of solar degradation efficiency of bio-composting leachate using Nd: ZnO nanoparticles

Composting leachate is one of the highly polluted liquids generated at landfills and compost plant. Therefore, the aim of this research work was to photodegrade leachate generated from a biocomposting plant from Iran by neodymium-doped ZnO hybrid nanoparticles (Nd:ZnO NPs). The photocatalytic degradation of leachate was optimized based on surface response methodology. For the experimental design and process optimization, the central composite design was applied. The parameters studied were the dosage of Nd:ZnO NPs, solution pH, contact time, H2O2 concentration, and leachate concentration. Using “ Design Expert software (Trial Version 7.0)”, totally 33 runs were considered for photodegradation studies. Mineralization of the leachate was confirmed by COD analysis. The response was assessed for different models and the high regression coefficient (R2 = 0.9782, Radj = 0.9909) between the variables and the response confirmed excellent estimation of experimental data by quadratic model. The optimum conditions (COD removal efficiency of 82.19) were found to be at pH 6.74, Nd-doped ZnO dosage of 1920 mg/l, leachate concentration of 2000 mg/l, contact time of 114.62 min, the H2O2 concentration of 12.56 Mmole, and dopant percentage of 0.75

Nanotechnological approaches in prostate cancer therapy: integration of engineering and biology

Nanocarriers have received special attention in biomedicine for the treatment of various diseases, especially cancer, as one of the leading causes of death worldwide. Nanocarriers can improve the potential of contemporary strategies in cancer therapy and also provide new methods for diagnosis and biosensing. The present review focuses on the biomedical application of nanocarriers in the treatment of prostate cancer (PCa), one of the most common urological cancers in men. The chemotherapeutic and radiotherapeutic potentials in PCa may be improved using nanocarriers by providing targeted drug delivery and inducing PCa cells' sensitivity via induction of cell death. Delivery of nucleic acid drugs such as siRNA, shRNA and CRISPR/Cas9 system by nanocarriers in PCa therapy enhances the intracellular accumulation of these therapeutics and increases their efficacy in gene expression regulation. The high proliferation rate and metastasis of PCa cells result in poor prognosis. They may be dually suppressed by nanocarriers, as nanoplatforms facilitate co-delivery of drugs and gene therapeutics in PCa suppression. Selectivity toward PCa cells may be enhanced via surface modification of the nanocarriers to facilitate internalization via endocytosis. In addition to their applications for PCa treatment, nanocarriers mediate the detection of biomarkers for PCa diagnosis