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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]

In the present study, the emission of BTEX compounds has been investigated in a one-year period (2016–2017) in Tehran city. According to, 26 sampling stations were selected in different parts of the city and had been sampled in four seasons of year to determine the concentration of BTEX as well as other meteorological parameters such as temperature, humidity and wind speed. Spatial distribution analysis of BTEX was introduced by using the Inverse Distance Weighting (IDW) method in Arc GIS 10.3. Also, to determine the carcinogenic and non-carcinogenic risk of target compounds, Monte Carlo simulation was used. The results showed that the annual mean of benzene, toluene, ethylbenzene, m-xylene and o-xylene were 30.08 ± 21.97, 54.17 ± 40.29, 25.81 ± 15.21, 27.83 ± 19.1 and 23.16 ± 12.28 μg/m3, respectively. According to the result, the maximum and minimum concentrations of BTEX were in the center and north of the city, respectively. Temporally, the maximum value of BTEX was 232.61 ± 123.93 µg/m3 in the autumn and the minimum value was 57.88 ± 24.93 µg/m3 in the spring. The result obtains from the inhalation lifetime cancer risk (LTCR) indicative the carcinogenic potential of benzene. Noncarcinogenic risk index, namely the hazard quotient (HQ) for all BTEX compound except benzene concentration in the autumn (1.55), were lower than 1 degree so they were not harmful to human health. [ABSTRACT FROM AUTHOR]

Due to rapid population growth and climate change all over the world, wastewater treatment and reuse, coupled with their understanding of their characteristics, have been extensively developed. This study was carried out with a systematic examination of the carwash wastewater properties. The systematic review was conducted using “PRISMA” checklist and “carwash wastewater”, “car wastewater”, “vehicle wastewater”, “carwash wastewater treatment” keywords. In general, 429 articles were chosen from these databases, which were included in this study after reviewing entry criteria only 56 of these articles. Most articles (56.36%) were related to Asia. Physicochemical, biological, heavy metals and resistant pollutants were investigated in this study. The results of the detailed analysis of articles published in the carwash wastewater domain have shown low organic and mineral pollutant composition. This suggests carwash wastewater as a reliable source of reuse. The most important features of carwash wastewater for human health are heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls and surfactants, which should be considered. This study can be considered as a comprehensive research in the future of carwash wastewater. [ABSTRACT FROM AUTHOR]

This study investigates the kinetic model of chemical oxygen demand (COD) removal from olive oil mill synthetic wastewater through electrocoagulation using stainless steel and aluminum as a cathode and anode electrodes, respectively. The one-factor method was used to evaluate interactions between the operational parameters that affect COD removal. A reactor with a volume of 250 mL was utilized to perform the process. The optimal conditions with 99% COD were found to be the current density of 12.5 mA cm-2, 400 mg L-1 NaCl as supporting electrolyte, initial COD concentration of 17,500 mg L-1, and operation time of 60 min. The highest efficiencies of COD removal were achieved at pH values of 5 and 9 using stainless steel and aluminum electrodes as cathode and anode, respectively. The results demonstrated a direct relation between the coagulant adsorption rate and efficiency of COD removal by olive oil. According to the obtained results, the process follows an intra-particle diffusion kinetic model, in which absorption capacity is high at the beginning, and removal efficiency increases over time. [ABSTRACT FROM AUTHOR]

The present study was to enhance catalytic ozonation process (COP) using ferric (Fe)- ethylenediaminetetraacetic acid (Fe-EDTA) integrated with an electrocoagulation (EC) process for landfill leachate pretreatment. For this purpose, the effect of operating parameters such as ozone and Fe-EDTA concentrations, current, initial pH, and reaction time were investigated. The findings revealed that the EC process and single ozonation process (SOP) could alone reduce chemical oxygen demand (COD) in landfill leachate by 23% and 39%; respectively. Moreover, integration of both processes at 100 mA current, 400 mg h−1 ozone concentration, and 3 h reaction time could significantly improve COD reduction to 70%. As well, current efficiency and ozone consumption in the proposed system could considerably develop compared with EC process and SOP. The integrated electro-catalytic SOP using Fe-EDTA could be operated at neutral pH value, which the COD removal efficiency was obtained 79.7%. Subsequently, biochemical oxygen demand (BOD 5)/COD ratio of effluent increased to 0.64. Examining pseudo-first-order and pseudo-second-order kinetics, it was realized that constant rate in the system had augmented. These results also indicated that the modified process using Fe-EDTA was a promising landfill leachate pretreatment technique that could significantly enhance COD removal efficiency and BOD 5 /COD ratio, and ultimately decrease time and sludge production. Image 1 • High COD removal using modified electrocatalytic ozonation process. • The proposed electrocatalytic ozonation process could be operated at neutral pH value. • Decrease of ozone consumption at the electrocatalytic ozonation. • Increasing of the BOD 5/ COD ratio. [ABSTRACT FROM AUTHOR]