Study of lead adsorption on activated carbons

In this study, the removal of lead (II) from water using commercial  activated carbons from wood and coconut shell were investigated in acidic medium (pH = 4). Atomic absorption spectrometer (AAS) was used to investigate initial (C0) and (equilibrium) (Ce) solution concentrations. Powder and granular activated carbons showed different adsorption capacity. The amount of Pb2+ adsorbed reached44.58, 38.96 and 39.06 mg/g for CPA, CGA 830 and CGA 1230 respectively at 25 °C. Langmuir and Freundlich adsorption models were used to represent the equilibrium data. Despite the high value of coefficient (R2) from Freundlich model, the best interpretation for the experimental data was given by the Langmuir model. The work showed that using powder activated carbon from wood exhibited relatively high adsorption capacity than activated carbon from coconut shell.Keywords: Lead, activated carbon, adsorption, Langmuir, isotherm

Study of adsorption of imidacloprid onto two different textures of soils

The main goal of this research is to evaluate the potential for imidacloprid to contaminate water and ground water. For this purpose, the adsorption of imidacloprid on two different soils is investigated. Physicochemical  properties such as texture, organic matter, pH of the two soils are investigated. Both soils have high organic matter and the same pH but different textures. The kinetic study of adsorption on these soils over 90 days yielded a mean half-life of 60 days. Furthermore, adsorption kinetics of imidacloprid was studied and the rate of sorption was found to conform to pseudo-second-order kinetics with 3.10 mg/g/h and 10.204 mg/g/h for soils of banana field and cocoa field respectively. Equilibrium isotherm data were analyzed according to Langmuir, Freundlich and Redlich–Peterson equations. The Redlich–Peterson isotherm gave the best correlation for the adsorption of imidacloprid adsorption on soils. The maximum adsorption capacities were determined to be 4.139 mg/g and 5.74 mg/g of soils from banana field and cocoa field respectively.The differences in adsorption capacities may be due to the effect of soils textures.Keywords: Imidacloprid, soils textures, adsorption, Redlich-Peterson model, Freundlich model, HPLC

Sugar-sweetened carbonated beverage consumption correlates with BMI, waist circumference, and poor dietary choices in school children

<p>Abstract</p> <p>Background</p> <p>The prevalence of obesity and overweight is increasing globally. Frequently coexisting with under-nutrition in developing countries, obesity is a major contributor to chronic disease, and will become a serious healthcare burden especially in countries with a larger percentage of youthful population. 35% of the population of Saudi Arabia are under the age of 16, and adult dietary preferences are often established during early childhood years. Our objective was to examine the dietary habits in relation to body-mass-index (BMI) and waist circumference (W_C), together with exercise and sleep patterns in a cohort of male and female Saudi school children, in order to ascertain whether dietary patterns are associated with obesity phenotypes in this population.</p> <p>Methods</p> <p>5033 boys and 4400 girls aged 10 to 19 years old participated in a designed Food Frequency Questionnaire. BMI and W_C measurements were obtained and correlated with dietary intake.</p> <p>Results</p> <p>The overall prevalence of overweight and obesity was 12.2% and 27.0% respectively, with boys having higher obesity rates than girls (P ≤ 0.001). W_C and BMI was positively correlated with sugar-sweetened carbonated beverage (SSCB) intake in boys only. The association between male BMI and SSCB consumption was significant in a multivariate regression model (P < 0.0001). SSCB intake was positively associated with poor dietary choices in both males and females. Fast food meal intake, savory snacks, iced desserts and total sugar consumption correlated with SSCB intake in both boys (r = 0.39, 0.13, 0.10 and 0.52 respectively, P < 0.001) and girls (r = 0.45, 0.23, 0.16 and 0.55 respectively, P < 0.001). Older children reported eating significantly less fruit and vegetables than younger children; and less eggs, fish and cereals. Conversely, consumption of SSCB and sugar-sweetened hot beverages were higher in older versus younger children (P < 0.001). BMI and W_C were negatively correlated with hours of night-time sleep and exercise in boys, but only with night time sleep in girls, who also showed the lowest frequency of exercise.</p> <p>Conclusions</p> <p>A higher intake of SSCB is associated with poor dietary choices. Male SSCB intake correlates with a higher W_C and BMI. Limiting exposure to SSCB could therefore have a large public health impact.</p

Determination of glyphosate by high performance liquid chromatography (HPLC) without prior extraction

The aim of this study was to design a glyphosate analysis method. This molecule is an organic pollutant from water and soil. We have developed a chromatographic method with phenylisothiocyanate. This moleculehas allowed obtaining an intermediate molecule with the glyphosate being easily detectable in chromatography. The peak relating to this intermediate was identified using a comparison with several samples, including ablank. The tests determined the retention time (RT) of glyphosate at 1.6 min and the values of the percentage of accuracy and repeatability of the method

Weight loss effects from vegetable intake: a 12-month randomised controlled trial

Background/Objectives: Direct evidence for the effects of vegetable intake on weight loss is qualified. The study aimed to assess the effect of higher vegetable consumption on weight loss. Subjects/Methods: A single blind parallel controlled trial was conducted with 120 overweight adults (mean body mass index=29.98 kg/m2) randomised to two energy deficit healthy diet advice groups differing only by doubling the serving (portion) sizes of vegetables in the comparator group. Data were analysed as intention-to-treat using a linear mixed model. Spearmans rho bivariate was used to explore relationships between percentage energy from vegetables and weight loss. Results: After 12 months, the study sample lost 6.5±5.2 kg (P0.05 interaction). Both groups increased vegetable intake and lost weight in the first 3 months, and the change in weight was significantly correlated with higher proportions of energy consumed as vegetables (rho=-0.217, P=0.024). Fasting glucose, insulin and triglyceride levels decreased (P\u3c0.001 time) and high-density lipoprotein cholesterol levels increased (P\u3c0.001 time), with no difference between groups. Weight loss was sustained for 12 months by both groups, but the comparator group reported greater hunger satisfaction (P=0.005). Conclusions: Advice to consume a healthy low-energy diet leads to sustained weight loss, with reductions in cardiovascular disease risk factors regardless of an emphasis on more vegetables. In the short term, consuming a higher proportion of the dietary energy as vegetables may support a greater weight loss and the dietary pattern appears sustainable