Adsorption of hexavalent chromium from aqueous solutions by wheat bran

In this research, adsorption of chromium (VI) ions on wheat bran has been studied through using batch adsorption techniques. The main objectives of this study are to 1) investigate the chromium adsorption from aqueous solution by wheat bran, 2) study the influence of contact time, pH, adsorbent dose and initial chromium concentration on adsorption process performance and 3) determine appropriate adsorption isotherm and kinetics parameters of chromium (VI) adsorption on wheat bran. The results of this study showed that adsorption of chromium by wheat bran reached to equilibrium after 60 min and after that a little change of chromium removal efficiency was observed. Higher chromium adsorption was observed at lower pHs, and maximum chromium removal (87.8 %) obtained at pH of 2. The adsorption of chromium by wheat bran decreased at the higher initial chromium concentration and lower adsorbent doses. The obtained results showed that the adsorption of chromium (VI) by wheat bran follows Langmuir isotherm equation with a correlation coefficient equal to 0.997. In addition, the kinetics of the adsorption process follows the pseudo second-order kinetics model with a rate constant value of 0.131 g/mg.min The results indicate that wheat bran can be employed as a low cost alternative to commercial adsorbents in the removal of chromium (VI) from water and wastewater

Effect of omega-3 fatty acids supplementation on anthropometric indices in children and adolescents: A systematic review and meta-analysis of randomized controlled trials

Background Childhood obesity is a major public health problem with a global prevalence greater than 23 . Omega-3 polyunsaturated fatty acids (omega-3 FAs) supplementation may improve anthropometric indices by increased energy expenditure, attenuated appetite, elevated adiponectin levels, though current evidence is still inconclusive. � Objective The aim of this systematic review was to conduct the first comprehensive meta-analysis of randomized controlled trials on the association between omega-3 FAs supplementation and anthropometric indices in children and adolescents. � Methods We performed an extensive online database search of the published literature using the SCOPUS, Web of Science, PubMed, EMBASE, and Cochrane library databases from the index date through April 2019. Six studies met inclusion criteria. Changes in anthropometric indices (weight, BMI and waist circumference) were extracted from each article. Statistical heterogeneity was assessed by calculating the I2 statistic. We used the standardized mean difference (SMD) with 95 confidence interval. The meta-analysis was performed based on a random effects model. � Results This meta-analysis demonstrated that omega-3 FAs supplementation had no effect on reducing body weight (SMD = -0.00, 95 CI -0.26 to 0.25), BMI (SMD = -0.07, 95 CI -0.32 to 0.17) and waist circumference (SMD = -0.16, 95 CI -0.51 to 0.19). � Conclusions Omega-3 FAs supplementation did not change anthropometric indices in children and adolescents. Further large-scale studies with larger sample sizes in children and adolescents are needed to clarify the effects of omega-3 FAs. © 2020 Elsevier Lt