Search

The olive oil extraction industry is one of the most extensive industries, especially in the Mediterranean region. The wastewater produced in this industry contains high concentrations of organic pollutants, resistant and toxic compounds that, if not treated, can threaten the health of the environment. In the present study, the optimisation of the combined process of electrocoagulation and peroxone using central composite design of the response surface methodology with the help of Design-Expert V.11 The parameters of current density (0.06–0.73 A dm−2) and reaction time (5–45 min) in the process of electrocoagulation and the parameters of hydrogen peroxide concentration (4–12 ml) and reaction time (10–90 minutes) in the peroxone process were investigated on the COD removal efficiency. The design results showed that the quadratic model was significant for both processes and was determined as the selected model. The optimal conditions determined by the software in the process of electrocoagulation were 0.5 A dm−2 and 34 minutes and in the peroxone process, concentration of hydrogen peroxide and the time were obtained 12 ml and 62 minutes, respectively. In these conditions, the COD removal efficiency of the processes was determined 79.8% and 52.8%, respectively. Under optimal conditions, in peroxone process ozone consumption was reduced to 0.88 mg per mg of removed COD. Also, according to the results of Pseudo-first-order kinetics, constant rate increases with increasing of hydrogen peroxide concentration. The results obtained in this study were confirmed the application of electrocoagulation process along with advanced oxidation of proxone for effective treatment of effluents of this industry and similar industries. [ABSTRACT FROM AUTHOR]

The contamination of milk and its products with heavy metals has toxic and dangerous effects on human health. This study aimed to determine the heavy metal concentration and health risk assessment resulting from them in four different brands of Pasteurized milk consumed in Gorgan city, Iran. This study was performed during three seasons (summer, autumn and winter). Sixty different samples of pasteurized milk of four common brands were selected and analysed. Samples were digested in the laboratory by using nitric acid method digestion, and the heavy metal concentration was measured by using the linear regression based on the height of the peaks of the voltammograms. Also, health risk assessment was analysed by Oracle® Crystal Ball. According to the results, the overall mean (n = 60) concentration of Pb, Cd, Cu and Zn in all of the analysed milk samples was 0.02, 0.023, 0.97 and 4.31 µg/g, respectively. Based on these results, about 67% had Pb content lower than the codex limits, almost 70% of all milk samples had Cd content higher than the permissible limit, and Cu concentration in all milk samples was under the mentioned permissible limits. Zn concentrations in all samples were exceeded the permissible limits. HRI values in adults and children via consumption of pasteurized milk in all of the analysed samples were within the safe limits (HRI < 1). Based on these findings, monitoring of contaminants in milk and other dairy products prevented the probably side effects of these heavy metals on human health. [ABSTRACT FROM AUTHOR]