Selecting the best scenario for urban waste management using life cycle assessment method and SWOT matrix (Case study: Behbahan county)

The development of urbanization and the growing population of cities and consequently the large increase in the volume of municipal waste, has made solid waste management an important problem in urban planning. Waste is an inevitable product of any society and waste management is one of the main needs of that society. The present study in 2021-2022 has used the life cycle evaluation approach and SWOT matrix in order to select the best scenario of Behbahan city’s waste management system.

The study area produces an average of 120 tons of waste per day, of which 91% of waste is collected during the day and 9% at night. Per capita waste production is more than 900 grams per person. The share of waste production for each sector is as following: the residential sector is 76%, commercial 7%, industrial 5%, educational 2%, horticulture 6% and office and services 4%. 75% to 83% of residential waste is perishable materials and according to the analysis, about 79% of Behbahan city’s waste are perishable materials. Life cycle evaluation was carried out for the 5 following scenarios: 1- Recycling, compost and unhygienic landfill 2- Recycling, compost and sanitary landfill 3- Recycling and unsanitary landfill, 4- Recycling, incinerator and sanitary landfill 5- Recycling, anaerobic compost and digestion, incinerator and sanitary burial. Life cycle logging was done using IWM-2 model. Also, SWOT model was used to analyze the performance and status of gaps. It was considered to identify the threats and opportunities in the external environment of a system and to identify its internal strengths and weaknesses based on municipal waste management in order to assess the situation of the study area. Required data were collected by reviewing sources, preparing a questionnaire and field visits.

In this study, the third scenario is the current situation in the region and in terms of toxic emissions and ecological indicators, among all scenarios, it is the most environmental hazardous. Energy consumption in the first and fifth scenarios was higher than other scenarios due to unsanitary burial. The third and fifth scenarios have the most and the least role in methane production, respectively. According to the ecological index, the scenario of recycling, compost and anaerobic digestion, incinerator and sanitary burial is the best scenario. The third scenario is the worst-case scenario with the highest pollution load. The most important strengths, weaknesses, opportunities and threats according to the SWOT model are the use of appropriate urban transport machinery, lack of information about recycling and compost and landfilling of hospital and industrial waste with municipal waste, respectively. The implementation of the compost project was achieved using new technologies, abiding existing environmental laws and regulations and considering the proximity of municipal waste disposal to rural and residential areas.

The results obtained from the life cycle and the SWOT matrix can only be presented to decision makers through an environmental point of view. In order to make comprehensive decisions, economic and social factors must also be combined with environmental factors in evaluation and decision-making. Therefore, life cycle impact assessment methods and different models that exist to perform this assessment can be used to select and compare different waste management options and provide the best and most effective option for implementation, both ecologically and economically.