81 research outputs found
Preparation and optimization of macroalgae-derived solid acid catalysts
Solid acid catalysts were synthesized from macroalgae Sargassum horneri via hydrothermal carbonization followed by sulfuric acid sulfonation. A three-variable Box-Behnken design and optimization was used to maximize surface acidity. The optimal preparation conditions were found to be at the carbonization temperature of 217 °C, the carbonization time of 4.6 h and the sulfonation temperature of 108.5 °C. Under these conditions, the highest surface acidity achieved was 1.62 mmol g−1. Physical and chemical properties of prepared solid acid catalyst were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The results proved the grafting of –SO3H groups on an amorphous carbon structure. The catalyst activity was evaluated by the esterification of oleic acid with methanol. The sample prepared achieved 96.6% esterification yield, which was higher than the 86.7% yield achieved by commercial Ambersyst-15 under the same reaction conditions
Comparative study of acid yellow 119 adsorption onto activated carbon prepared from lemon wood and ZnO nanoparticles loaded on activated carbon
Multi-response optimization of ultrasound assisted competitive adsorption of dyes onto Cu (OH)2-nanoparticle loaded activated carbon: Central composite design
This paper focuses on the development of an effective methodology to obtain the optimum removal conditions assisted by ultrasonics to maximize the simultaneous removal of dyes, eosin Y (EY), methylene blue (MB) and phenol red (PR), by Cu(OH)2-NP-AC in aqueous solution using response surface methodology (RSM). The effects of variables such as pH, initial dyes concentrations (mg L−1), and amount of sorbent (mg) and sonication time (min) on the dyes removal were studied. A central composite design (CCD) was applied to evaluate the interactive effects of adsorption variables. A good correlation (with R2 > 0.940) between the statistical model and experiment was found for dyes removal from aqueous wastewater using the adsorbent. The optimum removal (99.20% ± 1.48) was thus obtained at pH 6.0, ultrasound time 2.5 min, adsorbent mass 20 mg and initial dye concentration at 5 mg L−1 for MB and EY and 12.5 mg L−1 for PR. The maximum adsorption capacity (Qmax) was calculated from the Langmuir isotherm as 32.9, 26.4 and 38.5 mg g−1 for the MB, EY and PR, respectively for the 0.015 g of sorbent. The adsorption kinetic data of the dyes were analyzed and was found fitting well in a pseudo-second-order equation. Adsorption isotherms and separation factors showed that the adsorbent displays a high selectivity toward one dye in a three-component system with an affinity order of PR > MB > EY. On the other hand, acoustic waves emitted by the cavitation bubbles render a direct effect on the process. This is attributed to the discrete nature and high pressure amplitude of the waves, which creates excessively high convection in the medium, causing adsorption of the pollutants. The chemical nature of the pollutants influences the enhancement effect of ultrasound
Case series of visceral leishmaniasis (Kala-azar) in Mazandaran and Golestan provinces, North of Iran
Visceral leishmaniasis (VL) or kala-azar is a parasitic disease caused by Leishmania donovani complex. Evidence suggests that visceral leishmaniasis is prevalent in some areas of Mazandaran and Golestan provinces. This study aimed to investigate the cases and also determining the causative agents of VL in these provinces. In this study, seven VL patients (mean age 1.5 years) admitted to the pediatric departments in Sari Booali Sina and Gorgan Taleghani hospitals, 2013–2016, were examined. The most common clinical and laboratory findings included prolonged fever, hepatosplenomegaly, anemia, pancytopenia, and hypergammaglobulinemia. Blood and bone marrow (B.M) samples were taken. Direct agglutination test (DAT) and rapid rK39 strip test were used as serologic tests and B.M microscopic slides were checked by species-specific PCR to identify the parasite species. All patients had positive rK39 and DAT tests. Examination of bone marrow smears demonstrated amastigotes of Leishmania (Leishman bodies) in the samples. The species of Leishmania in all B.M smears was Leishmania infantum. According to the identification of L. infantum as the major agent of VL in Mazandaran and Golestan provinces, increasing physician awareness (especially pediatric specialists) of the disease and conducting control programs in these areas are recommended. © 2016, Mazandaran University of Medical Sciences. All rights reserved
Improved adsorption performance of nanostructured composite by ultrasonic wave: Optimization through response surface methodology, isotherm and kinetic studies
© 2016 Elsevier B.V.In this work, ultrasound-assisted adsorption of an anionic dye, sunset yellow (SY) and cationic dyes, malachite green (MG), methylene blue (MB) and their ternary dye solutions onto Cu@ Mn-ZnS-NPs-AC from water aqueous was optimized by response surface methodology (RSM) using the central composite design (CCD). The adsorbent was characterized using Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) and EDX mapping images. The effects of various parameters such as pH, sonication time, adsorbent mass and initial concentrations of SY, MG and MB were examined. A total 33 experiments were conducted to establish a quadratic model. Cu@ Mn-ZnS-NPs-AC has the maximum adsorption efficiency (>99.5%) when the pH, sonication time, adsorbent mass and initial concentrations of SY, MG and MB were optimally set as 6.0, 5 min, 0.02 g, 9, 12 and 12 mg L-1, respectively. Sonication time has a statistically significant effect on the selected responses. Langmuir isotherm model was found to be best fitted to adsorption and adsorption capacities were 67.5 mg g-1 for SY, 74.6 mg g-1 for MG and 72.9 mg g-1 for MB. Four kinetic models (pseudo-first order, pseudo-second order, Weber–Morris intraparticle diffusion rate and Elovich) were tested to correlate the experimental data and the sorption was fitted well with the pseudo-second order kinetic model
Sulphate-Crosslinked Chitosan as an Adsorbent for the Removal of Congo Red Dye From Aqueous Solution
The efficacy of herbal medicines against Toxoplasma gondii during the last 3 decades: A systematic review
The objective of the current study was to systematically review papers discussing the efficacy of medicinal herbs against Toxoplasma gondii. Data were systematically collected from published papers about the efficacy of herbs used against T. gondii globally from 1988 to 2015, from PubMed, Google Scholar, ISI Web of Science, EBSCO, Science Direct, and Scopus. Forty-nine papers were included in the current systematic review reporting the evaluation of medicinal plants against T. gondii globally, both in vitro and in vivo. Sixty-one plants were evaluated. Most of the studies were carried out on Artemisia annua. The second highest number of studies were carried out on Glycyrrhiza glabra extracts. RH and ME49 were the predominant parasite strains used. Additionally, Swiss-Webster and BALB/c mice were the major animal models used. Alcoholic and aqueous extracts were used more than other types of extracts. Natural compounds mentioned here may be developed as novel and more effective therapeutic agents that improve the treatment of toxoplasmosis due to their lower side effects, higher availability, and better cultural acceptance compared with those of the chemical drugs that are currently being used. © 2016, Canadian Science Publishing. All Rights Reserved
Status of fasciolosis among domestic ruminants in Iran based on abattoir data: a systematic review and meta-analysis
Fasciolosis is considered as an ongoing neglected zoonotic disease in tropical regions of the world, relating to notable financial and public health issues. The current systematic review and meta-analysis was planned to determine the status of fasciolosis among domestic ruminants, including cattle, buffalo, goat, and sheep at the industrial slaughterhouses in Iran, between the years 2000 and 2016. Eight databases, four English and four Persian, were searched. Our findings demonstrated that 2.6 of all inspected livers of slaughtered ruminants were infected with Fasciola spp. during 2000�2016. The mean prevalence of fasciolosis for cattle, buffalo, goat, and sheep was 21, 4.2, 2, and 2.4, respectively. Additionally, most studies were performed on cattle 25 (39.6), sheep 24 (38 ), and goat 12 (19), respectively, and just 2 (3.1) studies were performed on buffalo. The prevalence of animal fasciolosis has significantly decreased among domestic ruminants in Iran except for cattle. In addition, the prevalence of this disease in Northern and Western regions of the country has remained at hypo-endemic level. The results present updated gathered information on the epidemiology of fasciolosis in domestic ruminants in Iran, and will expand the screening strategies to improve health and reduce economic impacts among farm animals
Modeling of quaternary dyes adsorption onto ZnO-NR-AC artificial neural network: Analysis by derivative spectrophotometry
The novel adsorbent i.e. ZnO-NR-AC was synthesized and used for the rapid removal of the quaternary dyes from the aqueous solution. The ANN model was used for the optimization and modeling of sonication time, amount of sorbent and dyes concentrations to study their simultaneous adsorption based on achievement of minimum mean squared error as criterion. The optimized parameters was found to be 4 min sonication time, 0.022 g of ZnO-NR-AC; MB, EY, CV and AO concentrations were 8.0, 9.7, 8.0 and 10.6 mg L-1 possible to achieve the removal percentage of 99.89, 99.2, 99.68 and 99.45% for MB, EY, CV and AO, respectively. The analysis of variance (ANOVA) support the high suitability of achieved equation for the efficient prediction of understudy adsorption system behavior that proofed by the presence of good agreement among the predicted and experimental data. The Langmuir isotherm model with maximum adsorption capacities were 89.29, 93.46, 87.52 and 88.5 mg g(-1) correspond to MB, CV, EY and AO, respectively. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved
Synthesis and characterization of mixed phase manganese ferrite and hausmannite magnetic nanoparticle as potential adsorbent for methyl orange from aqueous media: Artificial neural network modeling
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