(cest2017_01179) In-lake treatment with hydrogen peroxide for cyano-HABs control at Delft, NL (Lake Delftse hout) during the summer of 2015

摘要

The presence of harmful cyanobacterial blooms(cyano-HABs) in surface waters negatively impacts thesurrounding ecosystem while at the same time they limit itsusages (for drinking water, irrigation and recreationalpurposes). Current research activities are focusing ontreating Cyano-HABs at source as part of preventionormitigation strategy. Application of hydrogen peroxide(2.5 mg/L H_2O_2), for the selective and rapid termination ofCyano-HABs has been successfully applied in fresh waterlakes. It was therefore decided to treat the undesirablesymptoms of cyano-HABs in the lake Delftse hout (NL)with H_2O_2. The lake was treated with 5 mg/L H_2O_2. Ahigher concentration was used because of the floating layersof cyanobacterial scum. H_2O_2 rapidly reacted withcyanobacteria and left no residual concentration withinminutes of the application. The cyanobacteria population,mainly consisted of Aphanizomenon and Dolichospermum(formerly known as Anabeana), was reduced to less than1% and 3%of their initial concentration, respectively, 24hours after the treatment. No adverse effects were observedon other flora and fauna. Following treatment microcystinconcentration was below warning levels, and entrance tothe public was allowed two days after treatment.