Sediment, microorganism and water interaction
Any natural water body is characterised by the complicate interaction between water motion, suspeneded cohesive and non-cohesive sediment, and suspeneded micro-organisms. Depending on the concentration, solute nutrients support the metabolism of micro-organisms such as bacteria and algae, which tend to grow on suspeneded minerals more rapidly as compared to free-living organisms. Aggregate-attached organisms strongly affect the properties on the suspeneded sediment, and alter the rate of transport and deposition.
To study the interaction between sediment, micro-organisms and the water, the Fluis Laboratory has developed an innovative settling column (The BIOFLOC machine) that allows to control turbulence intensity, nutrient load, temperature and sediment concentration in a limited water volume. Sediment and micro-organisms forms biomineral flocs under fully controlled conditions, which are next observed with micro-PIV techniques.