Division of Soil and Water Management, Department of Earth and Environmental Sciences, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven, Belgium.
Division of Soil and Water Management, Department of Earth and Environmental Sciences, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven, Belgium.
Sci Total Environ. 2022 Mar 10;811:152483. doi: 10.1016/j.scitotenv.2021.152483. Epub 2021 Dec 16.
The reductive dissolution of iron (Fe) (oxy)hydroxides in sediments releases phosphorus (P) to the overlying water and may lead to eutrophication. Glauconite sands (GS) are rich in Fe and may be used as readily available P sorbents. This study was set up to test effects of dose and type of GS on the P immobilisation in sediments under hypoxic conditions. Three different GS were amended to a P-rich river sediment at doses of 0% (control), 5% and 10% (weight fractions) and incubated with overlying water in batch laboratory conditions. Glutamate was added to the solution after 15 days to deplete any residual dissolved oxygen from the sediment-water interface. In the first 15 days, the P concentration in the overlying water peaked to 1.5 mg P L at day 9 in the control and decreased to 0.9 mg P L at lowest Fe-dose and to 0.03 mg P L at the highest Fe-dose, the effects of GS type and dose were explained by the Fe dose. After 15 days, the added glutamate induced a second, and larger peak of P in the overlying water in sediment, that peak was lower in amended sediments but no GS dose or type related effects were found. This suggests that freshly precipitated P species at the sediment-water interface can be remobilised. This study highlights the potential for using this natural mineral as a cheap and easily available sediment remediation material, but its longevity under rare extreme conditions needs to be further investigated.
沉积物中铁（Fe）（氧）氢氧化物的还原溶解会将磷（P）释放到上覆水中，可能导致富营养化。海绿石砂（GS）富含 Fe，可用作易得的磷吸附剂。本研究旨在测试不同剂量和类型的 GS 对缺氧条件下沉积物中 P 固定化的影响。将三种不同的 GS 以 0%（对照）、5%和 10%（重量分数）的剂量添加到富磷河流沉积物中，并在批式实验室条件下用上覆水进行孵育。在 15 天后，向溶液中添加谷氨酸以耗尽沉积物-水界面处任何残留的溶解氧。在最初的 15 天内，上覆水中的 P 浓度在对照中于第 9 天达到 1.5mg PL 的峰值，并在最低 Fe 剂量下降至 0.9mg PL，在最高 Fe 剂量下降至 0.03mg PL，GS 类型和剂量的影响由 Fe 剂量解释。15 天后，添加的谷氨酸在沉积物中的上覆水中引起了第二次更大的 P 峰值，添加 GS 的沉积物中的峰值较低，但未发现与 GS 剂量或类型相关的影响。这表明可以重新迁移在沉积物-水界面处新沉淀的 P 物种。本研究强调了将这种天然矿物质用作廉价易得的沉积物修复材料的潜力，但在罕见的极端条件下其耐久性需要进一步研究。
