天然红土与苦草联合控制沉积物中磷释放

运用天然红土和苦草（RS+VS）的原位联合修复技术，探究单一及联合修复对污染底泥磷去除的影响.结果表明，RS与VS联合对沉积物P的去除能力高于两者单一修复，在37d的批量实验中，覆盖RS+VS组沉积物释放到上覆水中的磷被抑制了91%，与无覆盖RS+VS组的底泥释放磷相比，上覆水中溶解态活性磷（SRP）从1.41mg/L降至0.12mg/L.RS+VS联合修复对沉积物磷的固定作用显著，将不稳定的亚铁磷（Fe （II）-P）和铁铝结合磷（CDB-P）转变成惰性的钙磷（Ca-P），沉积物中的Ca-P含量增加了51%，Fe （II）-P，CDB-P分别降低了1%和24%，有效降低了底泥磷释放到上覆水的风险.综上，RS+VS联合可以应用于处理富营养化水域的内部磷负荷，实现两者协同去除沉积物磷，同时RS和VS两者价廉且广泛分布可作为一种潜在高效益的磷酸盐吸附剂应用于实际工程中.

Combined control of phosphorus release from sediment by red soil and Vallisneria spiralis

The effect of single and combined remediation on phosphorus removal from polluted sediment was studied by using the in situ combined remediation technology of red soil and Vallisneria spiralis(RS +VS). The results showed that the removal capacity of sediment P by RS and VS combined remediation was higher than that by single remediation. In the 37d batch experiment, the phosphorus released from sediment in the RS+VS group was inhibited by 91%. Compared with the phosphorus released from sediment in the RS+VS group without coverage, the dissolved active phosphorus (SRP) in the overlying water decreased from 1.41mg/L to 0.12mg/L. RS+VS combined remediation had a significant effect on the fixation of sediment phosphorus, The unstable ferrous phosphorus (Fe(II)-P) and iron aluminum bound phosphorus (CDB-P) were transformed into inert calcium phosphorus (Ca-P). The content of Ca-P in sediment increased by 51%, while Fe(II)-P and CDB-P decreased by 1% and 24% respectively, effectively reducing the risk of phosphorus release from sediment to overlying water. In conclusion, RS+VS combination can be applied to treat the internal phosphorus load in eutrophic waters to realize the coordinated removal of sediment phosphorus. At the same time, RS and VS are cheap and widely distributed, and can be used as a potential high-benefit phosphate adsorbent in practical projects.