فهرست مطالب khadijeh sajjadpour

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.

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.

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).

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.

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.

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.

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.

As the absorbent dose increases, the efficiency of the adsorption process increases, because larger amounts of adsorbent cause higher adsorption places.