Search published articles


Showing 3 results for Motalebi
Comparative Study of SMBR and Extended Aeration Activated Sludge Processes in the Treatment of Strength Wastewaters
M Gholami, A Sabzali, E Dehghani Fard, R Mirzaei, D Motalebi,
Volume 4, Issue 3 (1 2011)
Abstract

Background and Objectives: One of the complete treatment processes for industrial and municipal wastewater treatment is membrane bioreactor process which has dominant potential in process and operation sections. This study was conducted to compare the performance of extended aeration activated sludge (EAAS) with submerged membrane bioreactor (SMBR) systems in the treatment of strength wastewater, in the same condition.
Materials and Methods: The initial activated sludge was brought from the Plascokar Saipa wastewater plant. The Plexiglas reactor with effective volume of 758 L was separated by a baffle into the aeration and secondary sedimentation parts with effective volumes of 433 L and 325 L, respectively. The chemical oxygen demand (COD) concentration of the influent wastewater of the EAAS and SMBR systems were between 500-2700 and 500-5000 mg/L, respectively.
Results: Results showed that the SMBR system produced a much better quality effluent than EAAS system in terms of COD, biochemical oxygen demand (BOD5), total suspended solids (TSS) and ammonium. By increasing the COD concentration, the concentration of mixed liquor suspended solids (MLSS) and the removal efficiency of organic matter in the SMBR system, were increased regularly, however the removal efficiency of COD in the EAAS system was irregular. 
Conclusion: The average BOD5/COD ratio of effluent in the EAAS and SMBR systems were 0.708±0.18 and 0.537±0.106, respectively. These show that the organic matters in the effluent of the SMBR system was less degradable and thereupon more biological treatment was achieved. Nitrification process was completely done in the SMBR system while the EAAS system could not achieve to complete nitrification.

 


Comparing the efficiency of vacuum ultraviolet and ultraviolet-C for the degradation of Remdesivir in the contaminated water
Mahboobeh Motalebi, Gholamreza Moussavi, Sakine Shekoohiyan,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: Vacuum Ultraviolet (VUV)-based advanced oxidation is a new category of advanced purification processes, so this study aimed to compare the efficiency of VUV and Ultraviolet-C (UVC) processes in combination with H2O2 and PMS in degrading Remdesivir.
Materials and Methods: The photoreactor was investigated with VUV and UVC lamps in combination with H2O2 and PMS for Remdesivir degradation. Also, the effect of variables such as solution pH, H2O2 dose, Remdesivir concentration, the presence of radical scavengers and anions, as well as hydraulic retention time was considered in the continuous process of Remdesivir removal.
Results: The findings showed that the optimal pH in the processes of VUV, UVC, and their derivatives was equal to 7. By adding 1 mM of PMS and H2O2 to the VUV process, the degradation efficiency of Remdesivir was increased from 92.2 ± 0.4% to 98.3 ±2.1% and 100 ± 0.3%, respectively, after 30 min. Also, in the UVC process combined with H2O2 and PMS, the degradation efficiency reached 77.8 ± 1.5 and 85.2 ± 1.3% after 40 min, respectively. The degradation kinetics in the examined processes were as follows: VUV/H2O2 > VUV/PMS > VUV > UVC/H2O2 > UVC/PMS > UVC. The hydroxyl radical was the main reactive oxygen species that led to the decomposition of Remdesivir. The continuous operation of VUV/H2O2 showed that the removal efficiency of Remdesivir reached 94.7 ±0.8% after 40 min.
Conclusion: Considering the high rate of Remdesivir degradation by adding H2O2, the VUV/H2O2 process can be introduced as an efficient technology for the removal of antiviral drugs.
 

Risk identification and assessment in a battery-manufacturing industry using FMEA method, and estimating the ratio of the cost of accidents to prevention
Hossein Masoumbeigi, Davood Motalebi Peykani, Ghader Ghanizadeh, Hamed Akbari Jour, Maryam Esmaeili,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: The health and safety of the employees of any industry is one of the most important issues to prevent the occurrence of accidents. This study aimed to identify and assess related risks in a battery-manufacturing industry using FMEA method and estimate the ratio of the cost of accidents to prevention.
Materials and Methods: In this descriptive and analytical study, the production activities of the industry were first identified. Then the work process, employee duties, and Potential risks were determined by the HAZID method. Evaluation and prioritization of risks were done using FMEA method. Risks whose RPN was higher than 145 were determined as important risks and the ratio of incident cost to accident prevention was calculated.
Results: In 62 active units of this industry, 716 risks were identified and prioritized, 16 of which (2.23%) had RPN above 145 with the highest priority. The financial pulp unit with falling and fire hazards and the assembly unit with the risk of fumes and lead dust leakage with RPN 245 were among the most dangerous units and hazards identified in the industry. In all units except one unit, the ratio of the cost of accidents to prevention varied from 1.2 to 25.
Conclusion: The results showed that it is necessary to consider the correction of the important risks by the industry officials, according to the set priorities so that potential accidents caused by these risks are minimized. This prioritization can play an effective role in optimal risk management and reduce related costs.
 

Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb