渤海南部海域沉积物上覆海水与颗粒物中的磷与硅

Phosphorus and Silicon in overlying waters and suspended matter near sediment-water interface of the southern Bohai Sea

研究了渤海南部海域沉积物上覆水、悬浮颗粒物中P、Si的变化特征。上覆水体PO4-P、SiO3-Si的平均含量均低于大洋底层水PO4-P、SiO3-Si的平均含量 ,二者具有相似的循环控制机制。悬浮颗粒物中无机磷、生源态磷 (TIP、BP)的来源和循环控制机制不同 ,无机硅、生源态硅 (TISi、Si)有一定的相似性。稀释作用和表层沉积物中可交换态P、Si的循环控制上覆水体中P、Si的地球化学行为。颗粒物中TIP、TISi的行为受离子交换和化学吸附过程影响 ,其中化学吸附可能与Fe(III)的氧化物有关 ;生物过程对颗粒物中生源P、Si的地球化学行为有重要影响。

Geochemical behaviors of P and Si in overlying seawater and suspended particulates near sediment-seawater interface of the southern Bohai Sea were studied. In overlying seawater, concentrations of P and Si in this area were lower than in open seas. P and Si cycling mechanisms are similar, being controlled by freshwater dilution and cycling of available P and Si in surface sediment. In suspended particulates, the source and cycling mechanism of TIP and BP differ, while being similar to TISi and BSi. Behavior of TIP and TISi are influenced by ionexchange process and chemical adsorption, and the later probably related to Fe(Ⅲ) oxide. Both biotic and abiotic transfer processes are primarily responsible for P and Si exchange between overlying seawater and suspended particulates.