Iranian Journal of

Background and Objective: 2,4 dinitrophenol is observed in sewage produced from chemical and petrochemical industries. Contamination of drinking water with these pollutants causes toxicity, health problems and change in taste and odor. The present study was developed to evaluate the efficiency of removal 2,4-DNP through dried sludge adsorbent and modified calcium chloride sludge adsorbent.

Materials and Methods: At first, sludge was dried at temperature of 60 °C. Next, CaCl₂ was used to improve adsorption capacity. The removal efficiency of 2,4 dinitrophenol were determined by HPLC at wavelength of 360 nm. The effects of influencing factors including pH, initial pollutant concentration, contact time, and adsorbent dose were examined.                            
Results: The optimum pH of adsorption for both adsorbents was found to be 7. The optimum concentration of 2,4-DNP was 10 ppm. The results obtained from the present research showed that the removal of the contaminant using dried and modified sludge sorbent was increased from 72.6% to 86% at a dosage of 1.5 g. The adsorption kinetics were fitted with the pseudo second order kinetics model for both adsorbents. The isotherm data also showed that the adsorption of this pollutant on both adsorbents is fitted with the Freundlich model.
Conclusion: Results obtained from the present study indicated that the efficiency of the modified sludge ash is more than the non-modified sludge in 2,4 dinitrophenol removal. This can reduce adsorbent consumption in industrial treatment plants.

Background and Objective: Personal hygiene and adherence with health protocols in food preparation and distribution centers by operators are essential for controlling the transmission of infectious diseases. This study aimed to investigate the microbial contamination and compliance with health protocols among bakery workers in Mahmoudabad, Mazandaran, in 2020.
Materials and Methods: In a cross-sectional descriptive study, 149 samples were collected from the hands of workers in bakeries in Mahmoudabad. The microbial load was determined using the System Sure Plus device. Additionally, standard checklists, which included questions related to compliance with health protocols in the workplace, were used.  The collected data was then analyzed using SPSS 26 software.
Results: Among the studied samples, 51.1%had a microbial load higher than 30 RLU (Relative Light Units), 28.86%  had a microbial load of 10-30 RLU and 20.13% had a microbial load less than 10 RLU. Based on the results of the checklists, the rates of adherence to hand disinfection protocol, observance of social distancing, use of liquid soap, and use of a mask were 43.6%, 61.7%, 59.7%, and 53.7%, respectively. Additionally, data analysis revealed a significant relationship between business gown usage and microbial contamination on personnel's hands (p = 0.031).
Conclusion: Based on the results, it was evident that the workers' hand hygienewas in a concerning condition, posing a potential threat to their overall well-being. Therefore, individual health education and food safety practices should be improved, and inspections by environmental health monitors should be considered to ensure stricter public health standards.
 

Background and Objective: There have been concerns about microbial contamination along the coastal cities in the north of the country, particularly in cities of Mazandaran province, which could pose health risks for swimmers and tourists. The present study aimed to quantitatively assess the risk of gastrointestinal diseases resulting from exposure to E. coli and enterococci bacteria during recreational activities on the beaches of Fereydunkanar.
Materials and Methods: In this cross-sectional descriptive study, 66 grab samples collected during the summer were analyzed to investigate microbial contamination in the recreational beach waters of Fereydunkanar.The Monte Carlo simulation method was used to calculate both daily and annual infection risks.
Results: The findings demonstrated that transmission of enterococci was more likely than that of E. coli in the swimming areas of these beaches. The average annual infection risk for E. coli was 0.41 for adults and 0.69 for children . Additionally, the annual risk of enterococci infection was 1 for adults and 0.99 children and, which exceeds the range advised by the WHO and EPA. These findings indicate that children have a higher infection risk compared to adults.
Conclusion: Unrestricted discharge of municipal and industrial wastewater effluents into sea and rivers can contribute to the presence of harmful microbes in beaches. By implementing effective environmental and recreational management strategies, it is possible to minimize the risk of public health hazards at recreational beaches while also preserving the natural beauty of these important public spaces.