|Mohsen Arbabi, Samaneh Shafiei, Sadeghi Mehraban, Abbas Khodabakhshi, Ashkan Abdoli, Arman Arbabi
Int J Env Health Eng 2022, 11:3 (1 January 1900)
Background and Aims: Severe contamination with organic compounds and very high color is characteristic of yeast industry wastewater. Discharging this wastewater into the environment has adverse effects on the environment. The present study was conducted to determine the efficiency of the electrocoagulation (EC) using aluminum electrodes for the removal of color, turbidity, and chemical oxygen demand (COD) from the baker's yeast industry wastewater. Materials and Methods: In this experimental study, the effect of current densities (60, 80, 100, and 120 A/m2) and reaction times (15, 30, 45, and 60 min) using aluminum electrode was investigated on removal efficiencies of COD, color, and turbidity. The pilot consisted of a reactor with a useful volume of 2.5 l of epoxy glass, a direct current power supply, and aluminum electrodes of 8 cm × 8 cm in diameter. Results: The highest removal efficiencies were obtained to be 83% for COD, 93% for color, and 96% for turbidity at density of 80 A/m2 and 45-min contact time (pH = 7). Under these conditions, the power and electrode consumption was 16.89 kWh and 94.3 g/m3, respectively, and the treatment cost of wastewater was estimated to be 1.5 $ per each cubic meter. Conclusion: The results showed that EC process using aluminum electrode is an appropriate and effective method for removing color, turbidity, and COD from baking industry wastewater.
|Shabnam Shahrokhi, Hamid Mirhosseini, Gholam Hossein Halvani, Sara Jambarsang
Int J Env Health Eng 2022, 11:2 (1 January 1900)
Aim: Anxiety reduces performance at work. Anxiety is significantly prevalent among medical staff in general, and especially operating room staff. The present study was an attempt to investigate the effect of suction-induced white noise on anxiety and hemodynamic parameters of operating room staff during cesarean section. Materials and Methods: The present study was a crossover, single-blind clinical trial on 29 scrub staff during cesarean section. The subjects were assigned once to the control group and once to the intervention group with a 10-day washout period. In the intervention group, the suction machine was left on during surgery for 3 days in a row, but in the control group, the suction machine was switched off in idle times to make sure that noise exposure time would remain below 30 min. Hemodynamic parameters of subjects were measured on the last day immediately after surgery, and the Spielberger State-Trait Anxiety Inventory was used to measure the level of anxiety. SPSS 22 software and linear mixed model were used to analyze the collected data. Results: The control and intervention groups were not significantly different in terms of hemodynamic parameters, anxiety as well as the carryover-crossover effects (P > 0.05). A significant negative correlation was observed between anxiety score and age of the subjects (P < 0.05). Conclusions: Suction-induced white noise has no effect on anxiety and hemodynamic parameters of operating room staff. Adaptation to workplace noises can reduce the adverse effects of noise.