Phosphorus Entrainment Due to Resuspension in a Lowland River, Spree, NE Germany - A Laboratory Microcosm Study

Authors: Kleeberg, Andreas; Hupfer, Michael; Gust, Giselher

Source: Water, Air, and Soil Pollution, Volume 183, Numbers 1-4, July 2007 , pp. 129-142(14)

Publisher: Springer

Buy & download fulltext article:

Price: $47.00 plus tax (Refund Policy)

Abstract:

Resuspension of benthic phosphorus (P) often constitutes a high percentage of the annual P flux in lowland rivers. To study P entrainment at controlled shear velocity (u*) sediment from lowland River Spree of slower flowing (0.1-0.3 m s⁻¹) stretch Kossenblatt (KOB) and of faster flowing (0.5-0.7 m s⁻¹) stretch Freienbrink (FRB) was incubated in a microcosm at incrementally enhanced u* (0.34-1.9 cm s⁻¹). Particle and P entrainment rates as well as the number of particle-associated bacteria of fine-grained mud-like KOB sediment were much higher (16.7 g m⁻² h⁻¹, 104.9 mg P m⁻² h⁻¹, 15.47 10⁶ cells ml⁻¹) than those (4.3 g m⁻² h⁻¹, 2.1 mg P m⁻² h⁻¹, 3.06 10⁶ cells ml⁻¹) of coarser sandy FRB sediment. The microcosm used so far in marine research is suited to compare riverine resuspension suggesting the lower u* the more particles are deposited and the more P can be retained (KOB ≫ FRB). Conversely, correspondingly more and easier particulate P and bacteria can again be remobilised (KOB ≫ FRB) if u* increases. The general relationship found for u* and the entrainment of particulate P and bacteria as well as their decelerated and selective deposition where bacteria may stay longer in the water implies a temporarily enhanced P bioavailability, turnover and subsequent P transformations.

Keywords: bacteria; erosion chamber; hydrodynamics; particles; sediment; shear velocity

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s11270-007-9362-8

Affiliations: 1: Email: kleeberg@igb-berlin.de

Publication date: 2007-07-01