Criteria evaluation for the selection of biosolids management options for land application in the Philippines using analytic hierarchy process

Land application of biosolids for soil conditioning is a promising pathway to promote sustainability, especially in developing countries such as the Philippines. To maximize its benefits, heavy metals, pathogens, and emerging pollutants that come with biosolids must be properly managed using appropriate treatment processes. Furthermore, environmental impacts and associated costs when investing and operating on technologies must be considered. This study utilizes analytic hierarchy process to compute for priority weights for the following technologies: in-vessel composting, heat drying, electron beam irradiation and gamma ray irradiation. Weights for the 10 subcriteria were obtained through a pairwise comparison made by 45 wastewater professionals, which were then used to assess the four technologies. Based on the data and responses obtained, gamma ray irradiation emerged as the top technology among the technology options. However, in-vessel composting still remains an important option especially when more importance is given to vector attraction reduction, local technology readiness level (TRL), and operational expenses (OPEX).