| 英文摘要： |
Iron (Fe) minerals, organic matter (OM), and pH can effectively regulate phosphorus (P) transport in the soil. However, their respective contributions in this regard are still unclear. In this study, P transport in soil columns was investigated by monitoring breakthrough curves and transport model fitting, and the contributions of Fe and total organic carbon (TOC) concentrations, as well as pH to P retention, were determined using multiple linear regression (MLR). The results showed that the rate of P transport in Fe-rich laterite soil was significantly lower (retardation factor R = 458.5) than that in the other soil types (R = 108.4-247.6). Additionally, it was observed that OM formed rate-limited adsorption sites, causing the rapid release of labile P, and owing to P release and readsorption. Even though more significant P releases were observed, chernozem soil had an obvious inhibiting effect on P transport owing to its relatively high Fe content, and the high P-Fe increment (48.9-90.4%) indicated the essential role of Fe minerals in P immobilization. Further, P was readily transported in natural or artificially modified fluvo-aquic soils with high calcium concentrations, and it was also observed that the convection-dispersion equation (CDE) and Thomas models were suitable for describing P retardation and adsorption, respectively. Furthermore, the contribution weights of Fe and TOC concentrations as well as pH to P retardation, based on MLR calculations, were approximately 1.0, -0.3, and -0.2, respectively. Our findings can support the control of eutrophication pollution caused by P leaching. (C) 2021 Elsevier Ltd. All rights reserved. |
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