Utilizing solar energy for the purification of olive mill wastewater using a pilot-scale photocatalytic reactor after coagulation-flocculation.

This study investigated the application of a solar-driven advanced oxidation process (solar Fenton) combined with previous coagulation/flocculation, for the treatment of olive mill wastewater (OMW) at a pilot scale. Pre-treatment by coagulation/flocculation using FeSO4·7H2O (6.67 g L(-1)) as the coagulant, and an anionic polyelectrolyte (FLOCAN 23, 0.287 g L(-1)) as the flocculant, was performed to remove the solid content of the OMW. The solar Fenton experiments were carried out in a compound parabolic collector pilot plant, in the presence of varying doses of H2O2 and Fe(2+). The optimization of the oxidation process, using reagents at low concentrations ([Fe(2+)] = 0.08 g L(-1); [H2O2] = 1 g L(-1)), led to a high COD removal (87%), while the polyphenolic fraction, which is responsible for the biorecalcitrant and/or toxic properties of OMW, was eliminated. A kinetic study using a modified pseudo first-order kinetic model was performed in order to determine the reaction rate constants. This work evidences also the potential use of the solar Fenton process at the inherent pH of the OMW, yielding only a slightly lower COD removal (81%) compared to that obtained under acidic conditions. Moreover, the results demonstrated the capacity of the applied advanced process to reduce the initial OMW toxicity against the examined plant species (Sorghum saccharatum, Lepidium sativum, Sinapis alba), and the water flea Daphnia magna. The OMW treated samples displayed a varying toxicity profile for each type of organism and plant examined in this study, a fact that can potentially be attributed to the varying oxidation products formed during the process applied. Finally, the overall cost of solar Fenton oxidation for the treatment of 50 m(3) of OMW per day was estimated to be 2.11 € m(-3).

Prevalence and socio-demographic associations of undernutrition and obesity among preschool children in Cyprus.

OBJECTIVE: To estimate the prevalence of undernutrition and obesity in preschool children in Cyprus and identify possible associations. DESIGN: Cross-sectional study. SETTING: Private and public nursery schools. SUBJECTS: A representative sample (n=1412) stratified by age, gender, district and area of residence. INTERVENTIONS: Weight (kg) and height (cm) were obtained and BMI (kg/m2) was calculated. Z scores for weight-for-age, height-for-age, and weight-for-height were calculated using the cutoffs from the CDC/WHO 1978 reference. Socio-demographic associations with nutritional status were examined in a logistic regression analysis. RESULTS: The prevalence of undernutrition (WHO definition, Z-scores <-2) was low. Specifically the prevalence of underweight was 2.3%, wasting 2.8%, and stunting 1.1%. Undernutrition was associated with a low birth weight (LBW); odds ratio (OR) for underweight 4.1 (95% CI: 1.4, 12.2), P=0.012, stunting 5.2 (95% CI: 1.1, 23.3), P=0.033, and wasting 4.2 (95% CI: 1.3, 14.3), P=0.021. The prevalence of obesity (IOTF definition) was higher than undernutrition, and increased with age: 1.3% in 2 y olds to 10.4% in 6 y olds. Overweight and obesity prevalence were higher in rural (16.1%) than urban children (12.8%; P=0.046). Obesity in preschool children was associated with paternal obesity, OR 3.24 (95% CI: 1.59, 6.61), P=0.001, and maternal obesity 3.91 (95% CI: 1.78, 8.59), P=0.001. A birth weight (BW)> or =4000 g was associated with obesity compared to a BW between 2501 and 3000 g, OR 7.63 (95% CI: 1.91, 30.52), P=0.004. CONCLUSIONS: The prevalence of undernutrition among preschool children in Cyprus was low but obesity prevalence was higher. Parental obesity and high BW were significantly associated with obesity while LBW was associated with undernutrition in preschool children.

Waist circumference and waist-to-height ratio are better predictors of cardiovascular disease risk factors in children than body mass index.

BACKGROUND: Visceral adipose tissue is associated with increased risk for cardiovascular disease risk factors and morbidity from cardiovascular diseases. Waist measurement and waist-to-height ratio (WHtR) have been used as proxy measures of visceral adipose tissue, mainly in adults. OBJECTIVE: To validate body mass index (BMI), waist circumference and WHtR as predictors for the presence of cardiovascular disease risk factors in children of Greek-Cypriot origin. SUBJECTS AND METHODS: A total of 1,037 boys and 950 girls with mean age 11.4+/-0.4 y were evaluated. Dependent variables for the study were total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholestrol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and systolic (SBP) and diastolic (DBP) blood pressure. RESULTS: When children were divided into two groups according to the 75th percentile for BMI, waist circumference and WHtR, all dependent variables had higher mean values in the highest percentile groups in WHtR groups and almost all variables in BMI and waist circumference groups. Adjusted odds ratios for predicting pathological values of cardiovascular disease risk factors were slightly higher for the highest WHtR group for predicting lipid and lipoprotein pathological values and for the highest BMI groups in predicting high blood pressure measurement. Using stepwise multiple regression analysis to explain the variance of the dependent variables, waist circumference was the most significant predictor for all variables both for boys and girls, whereas BMI had the lowest predictive value for the detection of cardiovascular disease risk factors. CONCLUSION: Waist circumference and WHtR are better predictors of cardiovascular disease risk factors in children than BMI. Further studies are necessary to determine the cutoff points for these indices for an accurate prediction of risk factors.