UNASSIGNED: Eutrophication of Lake De Kuil (The Netherlands, 6.7  ha, maximum depth 9  m) has frequently caused cyanobacterial blooms resulting in swimming bans or the issue of water quality warnings during summer. The eutrophication was mainly driven by sediment @entity3151 (P)-release. The external P-loading was in the range of the critical loading for phytoplankton blooms. Hence, the reduction of the internal P-loading provided a promising way to reduce cyanobacterial blooms. To mitigate the cyanobacterial blooms, the combination of a low dose flocculant ( @entity24871 ; Flock) and a solid phase @entity4613 fixative ( @entity3740 modified @entity6638 ; Lock) was applied in May 2009. This combined approach both removed cyanobacterial biomass from the water column and also intercepted P released from the bottom sediments. Immediately after treatment, the Secchi depth increased from 1.5  m up to 5  m. Sediment P-release decreased from 5.2  mg  P  m(-2)  d(-1) (2009) to 0.4  mg  P  m(-2)  d(-1) (2010) but increased in later years. Mean summer concentrations of total P decreased from 0.05  mg  L(-1) (1992-2008) to 0.02  mg  L(-1) (2009-2014) and @entity38 -a from 16   g  L(-1) (1992-2008) to 6   g  L(-1) (2009-2014). Mean summer Secchi depth increased from 2.31  m (1992-2008) to 3.12  m (2009-2014). The coverage of macrophytes tripled from 2009 to 2011. In the winter of 2010/2011 Planktothrix rubescens bloomed, but cyanobacterial biomass decreased during the summers after the Flock and Lock treatment in comparison to prior years. After the Flock _ Lock the bathing water requirements have been fulfilled for six consecutive summers. As the sediment P-release has gradually increased in recent years, there is a risk of a reversion from the present mesotrophic state to a eutrophic state.

Management of eutrophication in Lake De Kuil (The Netherlands) using combined flocculant - XXXX modified @entity6638 treatment.

@entity24871 :: ('CHEBI:30808', 'Chemical') :: ['iron(III)chloride'] @entity3740 :: ('MESH:D007811', 'Chemical') :: ['lanthanum'] @entity4613 :: ('D010710', 'Chemical') :: ['phosphate'] @entity6638 :: ('MESH:D001546', 'Chemical') :: ['bentonite'] @entity3151 :: ('MESH:D010758', 'Chemical') :: ['phosphorus'] @entity38 :: ('MESH:D002734', 'Chemical') :: ['chlorophyll']
@entity3740 :: (MESH:D007811,Chemical) :: ['Lanthanum']
