Bibliometric overview of research progress, challenges, and prospects of rural domestic sewage: Treatment techniques, resource recovery, and ecological risk

Rural domestic sewage (RDS) is one of the foremost obstacles to achieving several global sustainable development goals. To identify and further drive future development in RDS treatment, bibliometric software (VOSviewer, CiteSpace, and the ‘Bibliometrix’ package in R) was used to analyze 512 relevant papers between 1991 and 2022. The results indicated an increasing trend in RDS-related publications, with China demonstrating the fastest growth in publications and close collaborations with the US and Canada. The authors' keyword co-occurrence network analysis revealed that the current research directions in RDS are efficient treatment technologies, resource recovery based on source separation, and ecological risks associated with RDS. Constructed wetlands are the most widely used option for treating RDS and can be combined with other treatment technologies. In addition, the source separation of RDS and its resourceful use have attracted widespread interest. However, the process must consider the potential ecological risks of emerging contaminants (ECs), especially antibiotic residues. Future research directions are mainly focused on: (1) establishing a comprehensive evaluation framework for RDS treatment facilities, (2) exploring in depth the technologies and strategies for source separation and resource utilisation of RDS, and (3) assessing the removal of ECs and related ecological risks. Overall, this review will contribute to the identification of current research trends, provide insight into RDS treatment and resource recovery, and further promote the development of this essential field.