Dissimilatory nitrate reduction processes including denitrification, anaerobic ammonium oxidation (ANAMMOX), and dissimilatory nitrate reduction to ammonium (DNRA) are crucial nitrogen (N) cycling pathways in freshwater ecosystems. Denitrification has long been considered as the primary pathway of N loss from aquatic environments. Recently, ANAMMOX and DNRA have been gaining more attention in N dynamics at the sediment–water interface. The ubiquitous presence of various sulfur (S) species in sediments makes them an important role on N transport. Interactions between dissimilatory nitrate reduction and the S cycle are mainly embodied by the inhibitory or promoting effects of sulfide on nitrate-reducing pathways, as well as the competition of sulfate with nitrate reduction for substrates. This review summarizes the current progress in the coupling of S cycling with nitrate-reducing pathways in freshwater sediments, the distribution and diversity of related microorganisms, as well as the functional genes encoding related enzymes. Future perspectives of related research are discussed in terms of coupled N cycling with other element cycles and molecular detection of functional bacteria to better understand and manipulate N cycling in freshwater environments.

The riparian zone is a transitional zone between aquatic and terrestrial ecosystems and is also the only passage for surface runoff to enter a river. The role of the riparian zone as a means for intercepting nonpoint source (NPS) pollution has been receiving growing attention and, in recent years, various ecological revetments have been developed to strengthen the interception of runoff pollutants. This research reviews the current development of ecological revetments in terms of NPS pollution control with a focus on the key functions and optimization methods of vegetation allocation and substrate configuration. Future research on improving the ecological revetments for enhanced NPS pollution control are also highlighted. This review is intended to provide a technical reference for the optimization and implementation of ecological revetment projects, and possible pathways for the effective control of NPS pollution.