The daily intake of trace elements through water resources and their adverse health effects is a critical issue. The purpose of this research was to assess the carcinogenic and non-carcinogenic risks of exposure to iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), chromium (Cr), lead (Pb), and arsenic (As) in groundwater resources of Sari city, Iran. The concentrations of the trace elements in a total number of 66 samples from the groundwater sources were measured using inductively coupled plasma mass spectrometry (ICP-MS). The hazard index (HI) levels of exposure to the trace elements from the groundwater sources for adults, teenagers, and children were 0.65, 0.83, and 1.08, respectively. The carcinogenic risk values of Cr and As in the groundwater sources for children, teenagers, and adults were 0.0001, 0.00009, 0.00007, 0.0003, 0.0002, and 0.0001, respectively, causing a total carcinogenic risk value higher than the acceptable range, and removing Cr and As from the groundwater resources is recommended for safe community water supply.
Background: Since the end of 2019, the emergence and spread of the Covid-19 pandemic has been raised as one of the challenges and problems of humanity in various dimensions, especially in the health sector. Due to the disease's high infectivity, controlling and breaking the chain of infection is especially important for vulnerable groups. Therefore, the present study was conducted to identify and evaluate Covid-19 control strategies in schools in Kashan. Methods: The present study is descriptive-analytical, using strategic management tools called strengths, weaknesses, opportunities, and threats (SWOT) and a quantitative strategic planning model (QSPM) of the situation of schools during the Covid-19 pandemic in 2021. Results: The findings from the SWOT matrix show the existence of 10 opportunities, 11 weaknesses, ten threats, and 14 strengths in the studied schools. The score of 2.45 obtained from the total scores of the internal factor analysis matrix indicates that existing weaknesses prevail over the schools' strengths in the disease control management field. Also, the score of 2.515 obtained from the analysis matrix of external factors shows that this institution has more favorable opportunities to reduce external threats and internal weaknesses. Conclusions: Based on these findings, the final solution for implementing the methods of controlling the disease of COVID-19 in Kashan schools is a conservative strategy. Therefore, the implementation of the presented strategies, especially the implementation of related educational guidelines, is necessary to control Covid-19.
Introduction: Nitrophenol compounds are toxic compounds found in industrial wastewaters. 2,4-dinitrophenol is the most dangerous compound among phenolic compounds. The aim of this study was to evaluate the removal of 2,4-DNP from wastewater by microwaved dried sludge adsorbent.
Materials and Methods: The results of 2,4-DNP removal were discontinuously obtained by the high performance liquid chromatography (HPLC) at a wavelength of 360 nm with various effective factors, such as contact time, pH, initial concentration of 2,4-DNP, and microwaved sludge dose. Finally, the results were analyzed using the kinetics and isotherm models. The equilibrium time was obtained 120 min. The maximum removal rate was obtained at pH 7.
Results: The findings indicated that the removal efficiency increased by increasing the adsorbent dose and decreasing the 2,4-DNP concentration. It was revealed that the removal of 2,4-DNP by microwaved sludge was 86%. The correlation coefficient value of linear and non-linear regression showed that kinetic studies follow the pseudo-second order model and isotherm studies follow the Freundlich isotherm model. The adsorption method relied entirely on pH and affected the adsorbent area attributes, ionization rate, and Delete percentage. When the pH was high, there was competition for the adsorption sites between hydroxide ions (OH) and 2,4-DNP molecules. At first, the adsorption process was high speed and gradually reached a stable level, because after a while, the adsorption sites become saturated.
Conclusion: As the absorbent dose increases, the efficiency of the adsorption process increases, because larger amounts of adsorbent cause higher adsorption places.
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