Titanate based photocatalysts for climate-efficient water treatment

Abstract: The sol-gel dip-coating method is a simple method to synthesize TiO2 thin film, using titanium butoxide and hydrogen peroxide as precursors. In this study in addition to TiO2 thin film, the photocatalytic activity of its intermediate products, titanium peroxide gel and ambient dried titanium peroxide film, was evaluated. The titanium peroxide gel was used directly after gelation, ambient dried titanium peroxide film coated on glass rings was used without thermal treatment and anatase TiO2 thin film was used after thermal treatment at 500oC. These photocatalysts were characterized by different characterization techniques and their adsorption and photocatalytic activity were evaluated by using methylene blue as a model pollutant. All three photocatalysts adsorbed the selected dye model and degraded it in the presence of sunlight but with different removal rate. It was found that the gel had the highest removal rate followed by ambient dried titanium peroxide film and TiO2 thin film. However, this sequence was found to be vice versa in the case of life span when the photocatalysts were reused. The photocatalytic study showed that all three photocatalysts are very effective for 100% degradation of methylene blue between 5-60 minutes of contacts times under sunlight irradiation. This can be a breakthrough of using titanate based photocatalyst for cost-effective adsorption and photocatalytic degradation of pollutants based on climate and availability of sunlight

An Investigation into Language Identity of Iranian EFL Teachers

This study presents a survey of Iranian English teachers and their language identity. The participants who completed the survey in this research included 60 English language teachers who belonged to different genders, age groups and English language teaching experiences. To investigate and collect the data, we used a validated questionnaire which included 19 items and was administered online and by hand. The results of the analyses showed that firstly participants possessed a moderate degree of language identity. The results also exhibited that there were no significant differences between the male and female participants regarding their language identity. However, there was a significant relationship between age and language identity. On the other hand, it was found that there were no differences between teaching experiences and language identity. Finally, we can come to conclusion that the results of this survey were very informative about how Iranian language teachers think of Persian language in comparison to English

Removal of Ibuprofen from aqueous solutions by Ozonation process

AbstractBackground and Aims: Ibuprofen (IBU) is one of the most consumed nonsteroidal anti-inflammatory drugs (NSAIDs) widely used in musculoskeletal and analgesic treatments. This study set out with the aim of assessing the efficiency of conventional ozonation process in a semi-batch plug-flow reactor in order to remove IBU fromaqueous solutions.Materials and Methods: A laboratory scale semi-batch plug-flow ozonation reactor was employed during the present study. Four variables including pH, dosage of ozone, hydraulic retention time (HRT), and initial Ibuprofenconcentration, which might affect the degradation of Ibuprofen, were taken into consideration. The IBU concentration was determined using HPLC.Results: Working under optimal operating conditions (pH = 8, HRT = 60 min, C=5 mg/L and Ozone dose 2/5 g/h), about 59% IBU degradation was noticed. Results also revealed that the degradation of IBU well fitted with the firstorderkinetics.Conclusion: The operating variables of pH, dosage of ozone, initial Ibuprofen concentration, and HRT were optimized using a plug-flow reactor to improve contact between dissolved ozone and the drug. pH and HRT were the most affecting variables. Furthermore, a predictive model allowing us to predict the percentage of IBP degradationas a function of pH and HRT under experimental conditions was obtained.Keywords: Non-steroidal anti-inflammatory drugs, Ibuprofen, Ozonation, Hydraulic retention timeFor downloading the full text please click here

Effect of synthesis method on NS-TiO2 photocatalytic performance

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Titanate based photocatalysts for climate-efficient water treatment

Abstract : T l dip-coating method is a simple method to synthesize TiO2 thin film, using titanium butoxide and hydrogen peroxide. In this study in addition to TiO2 thin film, the photocatalytic activity of its intermediate products, titanium peroxide gel and ambient dried titanium peroxide film, was also evaluated. The titanium peroxide gel was used directly after gelation, ambient..

Chitosan modified N, S−doped TiO2 and N, S−doped ZnO for visible light photocatalytic degradation of tetracycline

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Effect of synthesis method on NS-TiO² photocatalytic performance

Abstract : In this study, highly visible-light photoactive nitrogen and sulfur co-doped TiO2 nanoparticles and nanosheets were synthesized via sol-gel and hydrothermal methods, respectively. The photocatalytic activity of N,S-TiO2 photocatalysts were evaluated and compared by degradation of non-steroidal anti-inflammatory drugs, ibuprofen(IBP) and naproxen (NPX), under simulated solar light. The sol-gel method developed a mesoporous structure N,S-TiO2 nanoparticle which contains both anatase and rutile phases with large BET surface area (132 m2/g). N,S-TiO2 nanosheets with pure anatase phase, with larger mesoporous structure and a smaller BET surface area (64 m2/g) was formed via hydrothermal method. NS-TiO2 nanoparticles were coated on UVC-treated polycarbonate (PC) (NS-TiO2@PC) by simple deposition method. The results showed that under identical condition, N,S-TiO2 nanoparticles can degrade 85% and 99.3% of ibuprofen and naproxen while 71.6% of IBP and 99.1% of NPX were degraded by N,S-TiO2 nanosheets. Optimization results showed that maximum degradation efficiency was achieved at the optimum conditions: irradiation intensity 8.36 mW/cm2 (for ibuprofen) and 10 mW/cm2 (for naproxen), initial drugs concentration 10 mg/L and reaction time 121 min. Under this condition, the maximum degradation efficiency of 83% and 100% were achieved for ibuprofen and naproxen, respectively. The results of this study elucidate co-doped NS-TiO2 nanoparticles prepared by sol-gel methods are photocatalytically more effective and practically easier to reproduce for the practical application, both in terms of energy saving and cost reduction. The energy cost analysis indicated that sol-gel method for synthesis of N,S-TiO2 is more cost effective

Measurement of permethrin, deltamethrin and malathion pesticides in the wheat flour and breads and probabilistic health risk assessment: A case study from Kermanshah, Iran

Abstract: This study was conducted to investigate the residues of pyrethroid and organophosphorus pesticide in flour and breads which were collected from local markets in Kermanshah province, Iran. Four different types of breads and two types of flour samples with high distribution were taken from market and their residues of pesticides were measured. A simple dispersive liquid–liquid microextraction (DLLME) method with solidification of floating organic drop was developed for the measurement. The health risk of these pesticide on adults and children was assessed by target hazard quotient (THQ) using Monte Carlo simulation (MCS) method. About, 15% and 11.1% of total samples contained detectable levels of deltamethrin and malathion, respectively. None of the tested samples, showed any permethrin residue..

In vitro effect of nanosilver toxicity on fibroblast and mesenchymal stem cell lines

Nanotechnology presents countless opportunities to develop new and improved consumer products for the benefit of the society . A most prominent nanoproduct is nanosilver. Nanosilver particles are generally smaller than 100 nm and contain 20–15,000 silver atoms. Despite the wide application of nanomaterials, there is a serious lack of information concerning their impact on human health. In the previous study we reported the cytotoxic of nanosilver on osteoblast G292 cancer cell line and the amount of IC50 determined as 3.42 µg/ml (Moaddab et al., Iran. Nano Lett., Vol. 1, No. 1, January 2011, pp. 11-16). The purpose of the present study is to assess the biological assay of nanosilver on two normal cell lines of fibroblast (HF2), and mesenchymal stem cells . The effect of nanosilver on these cells is evaluated by light microscopy, and by cell proliferation and standard cytotoxicity assays. The results demonstrate a concentration-dependent toxicity for the cells tested, and IC50 was determined as 6.33, and 6.68 µg/ml in mesenchymal stem cell, and fibroblast HF2, respectively. There is no significant difference between the 24 h and 48 h of cells exposure to nanosilver. The results show that Nano-Ag possesses low toxicity to normal cells and can display potential application in cancer chemoprevention and chemotherapy

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations