The aim of this study was to evaluate the ability of sodium dichloroisocyanate (NaDCC) and sodium hypochlorite (NaOCL) for wastewater disinfection in a batch system with considering the contact time (5, 10, 15 min) and disinfectant concentration (0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2, 0.4 mg/L). Distilled water was mixed with wastewater to produce a given concentration of bacteria. Pure plate count (PPC) method was used to determine the initial and final concentration of bacteria. Three regression models including first order (FO), first order plus two way interaction (FO + TWI), and second order (SO) were used to fit the experimental data. The differences among group means were analyzed using Kruskal-Wallis and ANOVA analysis. The removal efficiency of NaDCC and NaOCl were 88.7 and 52.38% at an initial concentration of 0.01 mg/L and contact time of 10 min. The results of Kruskal-Wallis test showed that the mean of disinfection efficiencies were statistically different at different concentration of disinfectant (p-value < 0.05). However, there was no statistically significant difference between removal efficiency at different contact time based on one way ANOVA analysis (p-value > 0.05). These results were the same for both disinfectants. The modeling data showed that the best regression model to describe the disinfection mechanism was SO model with R 2 value of about 0.84 for both NaDCC and NaOCl. According to the present study, it can be concluded that the NaDCC is more suitable for water and wastewater disinfection because of higher efficiency at lower contact time and concentration.

Trace determination of triazine herbicides in fruit and vegetables using novel hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction followed by high-performance liquid chromatography-ultraviolet.

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This study aimed to assess the human health risk of some toxic metals/metalloids [lead (Pb), mercury (Hg), cadmium (Cd), nickel (Ni), chromium (Cr), and arsenic (As)] on infants via consumption of the breast milk of women living in urban areas of Kermanshah city, west of Iran. After collecting milk samples, the carcinogenic and non-carcinogenic risk assessment as well as uncertainty analysis of toxic metal levels were carried out. The order of concentration of heavy metals/metalloids in the breast milk samples was Cr (41.07 ± 23.19) > Ni (19.25 ± 11.81) > Pb (11.5 ± 4.48) > As (1.96 ± 2.04) > Cd (.72 ± 0.42) > Hg (0.31 ± 0.26). The results revealed that the levels of Cr and Pb in the breast milk samples were exceeded the World Health Organization (WHO) tolerable daily intake. In the breast milk samples a high levels of one of the trace elements As, Cd, Cr, Pb, and Ni were observed (over 73%) and in 40% of them the levels of Cr, Pb, Cd, As, and Ni were all above WHO tolerable daily intake. Moreover, the As-related point assessment of target risk factor (THQ) was higher than the allowable limit only for 1-month-old male neonates and 2-month-old female neonates (THQ > 1). In addition, Cr-related THQ scores were higher at all age and gender groups (THQ > 1). In conclusion, our findings suggest a potential risk of some metals for infants via the consumption of mothers' breast milk.