Risk assessment of using alborz industrial town's treated wastewater for restoration allahabad qazvin wetland using the bayesian network

Wetlands play an essential role in the ecosystem and have a significant impact on people's lives, so the restoration of destroyed wetlands is vital. With the lack of water sources, municipal and industrial wastewater can be used as alternative water sources for various purposes. Due to the presence of contamination in wastewater, the use of wastewater carries risks depending on which purpose it is used for. In this study, the risk of using Alborz Industrial Town treated wastewater in Qazvin province to restore Allahabad Wetland has been investigated. First, by visiting the project's origin, route, and destination and holding numerous meetings with experts involved in the project, influential factors were identified within the scope of the project. Then, an integrated hierarchical structure was created to express these factors. This structure starts from the initial nodes which are the quality of the effluent and leads to the final node. Using the water quality data of the Alborz Industrial Town treatment plant that were collected in the year of study and collecting the opinion of 20 experts in the form of a questionnaire in order to evaluate each node, the risk of the wastewater transfer project to Allahabad Wetland was calculated using the Bayesian network method. The academic version of GeNIe software was used to calculate the risk using the Bayesian network method. The results showed that among the middle nodes of the risk structure, the lowest and highest values are related to the nodes of heavy metals in the health environment risk subgroup and the increase of implementation costs in the economic subgroup. Despite the fact that the effluent quality is within standard limits in most parameters, environmental, cultural, social, economic and technical health risks are equal to 44, 47, 50 and 49%, respectively. The total risk of the project, which is the result of four risks, was calculated as 49%. According to the acceptable quality of wastewater and the calculated risks, the nodes and weights of other economic, technical and social sectors have influenced the final risk. Therefore, to reduce the risk of the project, these parts should be examined. The technical and economic part of the project has more potential for project failure. Before implementing the project, various environmental, social, technical, and economic dimensions should be carefully examined and the possibility of creating risk should be minimized. To reduce the risk of the wastewater transfer project to the wetland, pollutants such as heavy metals must first be removed from the wastewater, and social tensions should be prevented by increasing the awareness of the people of the region and also by allocating water quotas. Allahabad Wetland plays an important role in the ecosystem and people livelihood of the region, and with a more detailed examination of the dimensions of the plan and risk reduction in the four environmental, social, economic, and technical sectors, the implementation of the wastewater transfer project to Allah Abad Wetland can be effective in its restoration.