A microcosm experiment to determine the consequences of magnetic microparticles application on water quality and sediment phosphorus pools

作者：Funes A; del Arco A; Alvarez Manzaneda I; de Vicente J; de Vicente I^*

来源：Science of the Total Environment, 2017, 579: 245-253.

DOI：10.1016/j.scitotenv.2016.11.120

• Eutrophication
• Magnetic microparticles
• Microcosms
• Phosphorus
• Lake restoration

This study used microcosms to evaluate the effects of adding iron (Fe) magnetic microparticles (MPs) on water quality, focusing on P concentrations in the water column and sediment. Two treatments were considered for a constant 85:1 MP:P-Moblie molar ratio: T-W, applying MPs on the surface water layer; and T-S, applying MPs on the sediment. MP addition reduced P concentrations in lake water and sediment, with both treatments producing a mean reduction of 68 +/- 6% in dissolved inorganic P concentration (DIP) over a 70-day oxic period and reductions of 80 +/- 8% (T-W) and 80 +/- 4% (T-S) over a 5-day anoxic period. MPs also decreased reactive silicate (Si) concentrations by around 50% in both periods, but dissolved organic carbon (DOC) was reduced-by only 15% at 24 h after MP addition. Despite the marked decrease in DIP concentration due to MP addition, there was no-reduction in chlorophyll a (Chla), because post-treatment total P concentrations (>200 mu g L-1 vs. >700 mu g L-1 before treatments) remained higher than required for changes in the biological community (0.05-0.1. mg L-1). With T-S treatment, there was a reduction of 15% in P bound to Al oxides, clay minerals, and humic substances (P--> NaOH) and of 12% in labile organic P (Org-P-Labile) versus controls. P bound to humic substances (P--> NaOH,P- (Humic)) was reduced by 11-22% in both treatments. Finally, T-W rather than T-S treatments are recommended for future whole-lake applications to achieve more effective P removal from water and sediment and a higher percentage MP recovery.

• 出版日期2017-2-1