Environmental and Sanitary Risk Assessment of the waste water treatment plant in west of Ahwaz Using AHP and TOPSIS methods
Subject Areas : HSE Management
hamidreza pourkhabbaz
1
(Assistant Professor, Department of Environment, Faculty of Natural Resources, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran. *(Corresponding Authors))
azin azizi
2
(MSc. student of Evaluation and land use planning, Faculty of Natural Resources, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran.)
saeide javanmardi
3
(Instructor of Department of Environment, Faculty of Natural Resources, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran.)
Ali Reza Pourkhabbaz
4
(Associate Professor, Department of Environment, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran.)
Keywords: TOPSIS, Wastewater, Risk index, MCDM, wastewater treatment plant,
Abstract :
Background and Objective: Employed workers in wastewater treatment plants are always exposed to threats of risk factors in the workplace such as harmful physical, chemical and biological factors. Therefore, the present study assesses the safety, health and environmental risks in the wastewater treatment plant in west of Ahwaz city to investigate these risks and provide the necessary solutions. Material and Methodology: After the field visits, interviews to experts and staffs of treatment plant and internet researches (2018), a list of the most important risks was identified and given to the experts and staffs. In order to analyze and prioritize the risks, it was used from AHP and TOPSIS, which are multi-criteria decision-making methods (MCDM) and as well as the entropy technique to calculate the weight of the indicators. In Continuation to prioritizing strategies of factors, in order to removing the conflict between TOPSIS and AHP results, it was used the ranks mean.Findings: According to the results of AHP and TOPSIS, the most important safety and environmental risks that were identified, are impact to rotating parts of systems, entry of toxic materials and impermissible industrial wastewater and the dispersion of biogas from sludge digestion reservoirs. Also, according to the results of the ranks mean method, among the safety and health risks, it was Assigned impact to rotating parts of systems to score 1/5 the first priority, the electric shock and the dispersion of bad gas from wastewater to score of 3 and 3/5 were the second and third priority respectively. Among the environmental risks, it was Assigned entry of toxic materials and impermissible industrial waste water, the dispersion of biogas from sludge digestion reservoirs to score of 2 first priority, fire and explosion score of 3 second priority and fluctuations of waste wate discharge score of 3/5 the third priority.Disscotion & Conclusion: Given that the performance of wastewater treatment plants is a function of various human, natural, equipment and functional factors at the exploitation stage, therefore, management of these factors will help to improve the process of exploitation. In the present study, one of the most important management actions to reduce the level of risks identified, can pointed to apply of work safety guidelines, establishing of facilities and necessary equipment to burn additional gases and prevent their dangerous accumulation in the treatment plant environment, perform pre- treatment of industrial wastewater and continuous monitoring of effluent wastes to match with environmental standards.
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