New Approaches for Pb(II) Removal from Aqueous Media Using Nanopowder Sodium Titanosilicate: Kinetics Study and Thermodynamic Behavior.

Microporous sodium titanosilicate, Na2TiSiO5, has been successfully prepared using the sol-gel method. The structural and morphological characterization of synthesized product has been made via thermal analyses (TG-DTG), X-ray diffraction (XRD), and electron microscopy (SEM and TEM). Adsorption properties of the synthesized Na2TiSiO5 nanopowder for Pb(II) removal of aqueous media was investigated in different experimental conditions such as the contact time, the initial metal concentration, the pH, and the temperature. The Pb(II) adsorption on Na2TiSiO5 was discussed according to the kinetics and thermodynamics models. The adsorption kinetics of Pb(II) have been better described by the PS-order kinetic model which has the highest fitting correlation coefficients (R2: 0.996-0.999) out of all the other models. The adsorption results have been successfully fitted with the Langmuir and Redlich-Paterson models (R2: 0.9936-0.9996). The calculated thermodynamic parameters indicate that the Pb(II) adsorption is an endothermic process, with increased entropy, having a spontaneous reaction. The results have revealed a maximum adsorption capacity of 155.71 mg/g at 298 K and a very high adsorption rate at the beginning, more than 85% of the total amount of Pb(II) being removed within the first 120 min, depending on the initial concentration.

Health risk assessment of fluoride exposure due to groundwater consumption in Romania.

Fluoride has both beneficial and detrimental effects on human health. Concentrations of fluoride less than 1.0 mg/L in ingested water are beneficial for the rate of tooth decay, especially in children. The aims of the paper are as follows: (i) to monitor fluoride concentrations in drinking water samples (well water and tap water from the rural district of Valea Râmnicului, Romania); (ii) to study and select the optimal buffer solution and the optimal volume used in the analyses and (iii) to validate the potentiometric method for determining fluoride ions with a selective ion electrode. The values of fluoride ion concentrations in the groundwater samples and in tap water varied from 0.01 to 0.138 mg/L. The values for the hazard quotient for the studied samples varied from 0.01 to 0.13.

Risk factors of subclinical atherosclerosis in obesity and overweight.

OBJECTIVE: To examine the relationship of carotid intima-media thickness with weight-gain, overweight and obesity.. METHODS: The experimental, analytical study was conducted at the CF University Hospital, Cluj-Napoca, Romania, from 2012 to 2014, and comprised randomly selected in patients from the Medical Ward. The patients were divided into normal-weight subjects in Group I and overweight and obese subjects in Group II Intimate-media thickness was measured by carotid Doppler ultrasound. Data was analysed using SPSS 13. RESULTS: Of the 111 subjects, Group I had 27(%) and Group II had 84(%) subjects. Mean carotid intimamedia thickness was significantly greater (p<0.001) in Group II compared to Group I, especially in those with metabolic syndrome (p<0.001) and higher high-sensitivity C reactive protein (p<0.05). With the exception of Group II where there was a direct correlation (p<0.05) between triglycerides and intimamedia thickness, and an inverse correlation (p<0.05) between high-density lipoprotein and intimamedia thickness, no significant correlations were recorded (p>0.05). CONCLUSIONS: Intima-media thickness was found to be increased in asymptomatic overweight and obese subjects, significantly higher in those with associated metabolic syndrome and high levels of highsensitivity C-reactive protein, as an indication of the presence of early, subclinical atherosclerosis.