A REVIEW OF BIORETENTION TECHNOLOGY: NEW ISSUES, CURRENT RESEARCHES, AND LIMITATIONS OF NITROGEN REMOVAL PROCESSES UNDER MULTIPLE DRYING-REWETTING ALTERNATIONS

Bioretention technology has become an optimal tool in restorative stormwater management. However, the performance of nitrogen removal lacks good stability in adapting to environmental changes and responding to natural disasters. More specifically, nitrogen leaching is an important problem to be solved under multiple drying-rewetting alternations. Focusing on processes of nitrogen removal in multi-media, the purpose of this manuscript is to summarize the new issues of bioretention system controlling nitrogen, and to elucidate the processes of nitrogen removal from three aspects, including influence of multiple drying-rewetting alternations, characterization of nitrogen process in different spatiotemporal scales and contribution of multi-media. We suggest that future studies of bioretention technology should focus on the explanation of nitrogen leaching mechanism. Wherein, the coupling response relationship between processes of the nitrogen removal is a key issue. To understand this relationship, the quantitative contribution of multi-media to fate and transport of nitrogen, community structure of functional microbes, and microbial metabolic characteristics to nitrogen under multiple drying-rewetting alternations should be studied.