Assessment of Economic, Environmental, and Technological Sustainability of Rural Sanitation and Toilet Infrastructure and Decision Support Model for Improvement

Sanitation and toilets are important infrastructure for public health and societal stability. However, the adoption of adequate treatment technologies and techniques is a major challenge for both developing and underdeveloped areas. Answering the question of how to improve sanitation and toilet infrastructure in rural areas, for poverty alleviation, inequality mitigation, and good health and well-being under the Sustainable Development Goals, is more challenging compared with urban areas. Decision support models (DSMs) are important for selecting rural sanitation and toilet technologies. However, previous models have not fully respected local standards, needs, and operational environments, and are mainly limited to technological sustainability performance. To overcome such research gaps, this study developed a rural sanitation and toilet technology decision support model (DSM) assessing economic, environmental, and technological sustainability. Both technology and village weighting methods based on 217 general experts and seven local residents, respectively, were adopted to fully tailor indicator weights to rural contexts. The results showed an economic sustainability weight of 0.205, an environmental sustainability weight of 0.466, and a technological sustainability weight of 0.329. The sanitation and toilet technologies were divided into wastewater treatment technologies and toilet technologies, with the former subdivided into primary, secondary, and tertiary wastewater treatment technologies. This study confirmed that the PSO-GWO algorithm outperformed in accuracy and effectiveness. Accordingly, the PSO-GWO algorithm was adopted to demonstrate the optimization of sanitation and toilet technologies in four villages in plateau, mountain, plain, and basin areas. The study can assist local governments in selecting appropriate rural sanitation and toilet technologies during the planning phase. This can enhance the living standards of rural residents and promote sustainable rural development.