Research
| Title： | The effect of natural materials used as sediment remediation on phosphorus and nitrogen control in a mesocosm |
|---|---|
| First author： | Tang, Mengjuan; Deng, Qinghui; Li, Xiaowen; Cao, Xiuyun; Zhang, Zhimin; Zhou, Yiyong; Sun, Qingye; Song, Chunlei |
| Journal： | ENVIRONMENTAL SCIENCES EUROPE |
| Years： | 2020 |
| DOI： | 10.1186/s12302-020-00366-x |
| Abstract： | Background Achieving nitrogen (N) and phosphorus (P) control in sediment remediation projects by adding natural materials is receiving increasing attention. In this study, different natural materials, including iron-rich clay minerals, calcite, kaoline, sugarcane bagasse andPhragmitesdetritus, were applied to test their effects on N and P in a mesocosm experiment. Results Iron-rich clay minerals andPhragmitesdetritus had obvious advantages for P control; they resulted in almost undetectable levels of soluble reactive phosphorus (SRP) in the water column throughout the experiment. This finding can be explained by their strong P adsorption ability. The high level of available organic carbon in the sediment and water column after sugarcane bagasse addition provided enough electron donors for denitrification and dissimilatory nitrate reduction to ammonium (DNRA), which caused nitrate (NO3--N) deficiency and ammonium (NH4+-N) accumulation in the water column. Additionally, this resulted in anaerobic conditions, further fuelling the release of P from iron-bound P induced by anoxia. Thus, the amount of sugarcane bagasse applied should be considered carefully in order to balance denitrification and DNRA as well as P releases. Calcite andPhragmitesdetritus are recommended as remediation materials for N removal based on their significant promotion of denitrification and limitation of DNRA, which resulted in low NO3--N and NH4+-N levels. These results can be explained by the shifts in the functional microbial community composition and abundance after the addition of natural materials. Conclusions Iron-rich clay minerals andPhragmitesdetritus are promising sediment remediation materials for P immobilization due to their strong P adsorption ability. Taken together, the selection of sediment remediation materials should consider the N and P coupling relationship, to prevent NO3--N removal from causing P leaching or NH4+-N accumulation. |
