Fisher Caroline Buchanan, Vardanyan Lilit, Judy Jonathan D
Soil, Water and Ecosystem Sciences, University of Florida, Gainesville, Florida, USA.
J Environ Qual. 2025 Sep-Oct;54(5):1114-1127. doi: 10.1002/jeq2.70037. Epub 2025 Apr 30.
Five large-scale treatment wetlands, the Everglades Stormwater Treatment Areas (STAs), have been constructed in south Florida to reduce phosphorus (P) transport into the Florida Everglades. While the STAs have successfully reduced P entering downstream waterbodies by at least 77%, concentrations in outflow waters still exceed target values in many cases. It has been well documented that P compounds have varying effects on biotic and abiotic processes due to differing stability, bioavailability, and transport characteristics, making it critical to understand the nature of different P pools for improving long-term treatment wetland performance. Here, we used P nuclear magnetic resonance (P NMR) spectroscopy and P X-ray absorption near edge spectroscopy (XANES) to characterize P in surface water particulates entering and leaving the STAs. The most abundant P component at the inflows, as determined via P NMR, was orthophosphate (∼36% of P). XANES analyses of inflow waters indicated a lack of iron (Fe)-P bonds and suggested the presence of organic P. Though not commonly documented in this magnitude, polyphosphates were detected in all samples, ranging up to 39% at the outflows. Very little orthophosphate was detected at the outflows, while XANES analysis indicated the presence of hydroxyapatite in STA-2, suggesting internal transformation processes within the wetland. These findings suggest that outflow particulate P may be largely biogenic and that inorganic P may be apatitic in nature, as seen in STA-2. While STA research is relevant for Everglades ecosystem health, the approaches addressed here are informative for treatment wetland research and stormwater P management globally.
在佛罗里达州南部建造了五个大型处理湿地，即大沼泽地雨水处理区（STAs），以减少磷（P）向佛罗里达大沼泽地的输送。虽然STAs已成功将进入下游水体的磷减少了至少77%，但在许多情况下，流出水体中的磷浓度仍超过目标值。有充分的文献记载，由于稳定性、生物有效性和传输特性不同，磷化合物对生物和非生物过程有不同的影响，因此了解不同磷库的性质对于提高长期处理湿地性能至关重要。在这里，我们使用磷核磁共振（P NMR）光谱和磷X射线吸收近边光谱（XANES）来表征进入和离开STAs的地表水中颗粒物中的磷。通过P NMR测定，流入水中最丰富的磷成分是正磷酸盐（约占磷的36%）。对流入水的XANES分析表明缺乏铁（Fe）-P键，并表明存在有机磷。虽然这种量级的情况并不常见，但在所有样品中都检测到了多磷酸盐，在流出水中含量高达39%。在流出水中检测到的正磷酸盐很少，而XANES分析表明STA-2中存在羟基磷灰石，这表明湿地内部存在转化过程。这些发现表明，流出颗粒物中的磷可能主要是生物源的，而无机磷在性质上可能是磷灰石，如在STA-2中所见。虽然STA的研究与大沼泽地生态系统健康相关，但这里介绍的方法对全球处理湿地研究和雨水磷管理具有参考价值。
