Kinetics of phosphorus release from sediments and its relationship with iron speciation influenced by the mussel (Corbicula fluminea) bioturbation
Kinetics of phosphorus release from sediments and its relationship with iron speciation influenced by the mussel (Corbicula fluminea) bioturbation
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沉积物中磷释放的动力学及其与受贻贝（Corbicula Fluminea）生物扰动影响的铁形态的关系
DOI：
10.1016/j.scitotenv.2015.10.155
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发表时间：
2016-01-15
影响因子：
9.8
通讯作者：
Zhang, Chaosheng
中科院分区：
文献类型：
--
作者：
Chen, Musong;Ding, Shiming;Zhang, Chaosheng
研究了生物扰动对底泥中磷(P)稳定性的影响。采用高分辨率透析法(HR-Peeper)和薄膜扩散梯度法(DGT)分别获得了垂直分辨率为2 mm和1 mm的可溶和不稳定的P/Fe剖面。双壳类生物扰动使沉积物中可溶的活性磷(SRP)和DGT活性磷的浓度分别增加到-mm和-44 mm，分别为对照的116%和833%。生物扰动沉积物的分配系数小于对照(1964比3010 cm(-3)g(-1))，反映了沉积物对P的保留能力较弱。同时，生物扰动沉积物中DGT不稳定的P与SRP的浓度之比较大(0.20比0.03)，表明在生物扰动的影响下，沉积物固体对孔隙水SRP的再补给能力较强。DGT诱导的沉积物中磷释放通量模型进一步显示出更短的响应时间(277.9比18,670 S)和更高的固体磷释放速率(0.192比0.002天(-1))。相应地，生物扰动处理向上覆水中磷的通量增加了157%。双壳类生物扰动显著提高了水体中可溶性Fe(II)和DGT不稳定铁的浓度，分别达到对照的84%和334%。SRP和DGT-活性P分别与可溶性和DGT-活性Fe呈极显著正相关。结果表明，生物扰动沉积物中磷的释放是由于双壳类呼吸耗尽表层沉积物中的氧气，使易还原的Fe(Oxhyr)氧化物还原溶解，从而促进了沉积物中磷向孔隙水和上覆水的释放。(C)2015爱思唯尔B.V.保留所有权利。
The effects of bivalve (Corbicula fluminea) bioturbation on the lability of phosphorus (P) in sediments were investigated. The high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were employed to obtain soluble and labile P/Fe profiles at a vertical resolution of 2 and 1 mm, respectively. The bivalve bioturbation increased the concentrations of soluble reactive P (SRP) in pore water and DGT-labile P up to 116% and 833% of the control within the sediment depths from the sediment water interface (SWI) to -64 mm and -44 mm, respectively. The sediments with bioturbation had a smaller distribution coefficient than the control (1964 vs. 3010 cm(3) g(-1)), reflecting a weaker ability in retaining P. Meanwhile, the sediments with bioturbation had a greater ratio of the concentration of DGT-labile P to that of SRP (0.20 vs. 0.03), demonstrating a stronger ability to resupply pore water SRP by the sediment solids when they are affected by the bioturbation. The DGT-induced fluxes in sediments (DIFS) modeling further showed a much shorter response time (277.9 vs. 18,670 s) and a much higher rate (0.192 vs. 0.002 day(-1)) of the solids in release of P with the bioturbation. Correspondingly, the flux of P to the overlying water from the bioturbation treatment increased up to 157% of the control. The bivalve bioturbation significantly increased the concentrations of soluble Fe(II) and DGT-labile Fe up to 84% and 334% of the control from the SWI to -46mm, respectively. The SRP and DGT-labile P were highly correlated with respective soluble and DGT-labile Fe. It was concluded that the release of P from the sediments with bioturbation to the pore water and the overlying water was promoted by the reductive dissolution of easily reducible Fe(oxyhydr) oxides due to the depletion of oxygen in the top sediments from bivalve respiration. (C) 2015 Elsevier B.V. All rights reserved.