State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
MNR Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China.
Sci Total Environ. 2022 Feb 1;806(Pt 1):150540. doi: 10.1016/j.scitotenv.2021.150540. Epub 2021 Sep 24.
Phosphorus contamination in urbanized bays has been a major concern because the bay restoration is often hindered by complex P sources and behaviors. This study examined the spatiotemporal changes of P species and exchange potential in/between the water and sediment of the Jiaozhou Bay. The results indicated that dissolved P (TDP) and inorganic P (DIP) in the water ranged from 7.8-128.7 and 1.8-14.1 μg/L, respectively; while total P (TP) in the sediment ranged from 213.4-638.7 mg/kg. The TDP and DIP concentrations in the water were high in winter and low in summer, and generally decreased from northeastern or northern areas to southwestern or southern areas mainly due to phytoplankton bloom cycles and riverine and wastewater inputs. TP in the sediment was lower in the northwestern area due to solid dilution effect by the settlement of settled coarser suspended particles. Changes in aquatic geochemical conditions from rivers to bay caused P accumulation in estuarine sediment, with higher P partition in organic fraction (40%). Compared to the estuarine sediment, higher fractions of P were associated with carbonate (34%) and iron oxide (17%) minerals in the bay sediment. Equilibrium P concentrations at zero sorption (EPC) were 4.1-149.8 μg/L, which was substantially higher than the DIP concentration, demonstrating P release potential from the sediment. In addition, the P release potential was high in the northeastern area while P partition coefficient or buffer intensity (K) was high in the northwestern area. EPC was significantly positively correlated with soluble and exchangeable P in the sediment while K was significantly negatively correlated. These results can provide improved insights into P behaviors in an urbanized bay, particularly the P release potential and spatiotemporal change.
城市化海湾中的磷污染一直是一个主要关注点，因为海湾的恢复常常受到复杂的磷源和行为的阻碍。本研究考察了胶州湾水相与沉积物中磷形态的时空变化及交换潜力。结果表明，水中的溶解磷（TDP）和无机磷（DIP）分别为 7.8-128.7 和 1.8-14.1μg/L；而沉积物中的总磷（TP）为 213.4-638.7mg/kg。水中的 TDP 和 DIP 浓度冬季高、夏季低，且总体上自东北或北部向西南或南部降低，主要是由于浮游植物的繁殖周期以及河流和废水的输入。由于沉降的较粗悬浮颗粒的固体稀释效应，西北部地区的沉积物中的 TP 较低。河川到海湾的水相地球化学条件变化导致河口沉积物中磷的积累，其中有机部分的磷分比较高（40%）。与河口沉积物相比，海湾沉积物中磷与碳酸盐（34%）和氧化铁（17%）矿物的结合比例较高。零吸附时的磷平衡浓度（EPC）为 4.1-149.8μg/L，远高于 DIP 浓度，表明了沉积物中磷的释放潜力。此外，东北区域的磷释放潜力较高，而西北区域的磷分配系数或缓冲强度（K）较高。EPC 与沉积物中可溶性和可交换磷呈显著正相关，而 K 则与 EPC 呈显著负相关。这些结果可以深入了解城市化海湾中的磷行为，特别是磷的释放潜力及其时空变化。
