COPPER-BASED ALGAECIDES FOR TREATMENT OF NUISANCE AND HARMFUL CYANOBACTERIA BLOOMS: BLUNT TOOL OF PRECISION MANAGEMENT
The Metropolitan Water District of Southern California (MWD) manages raw-water reservoirs that are a source of drinking water for more than 19 million people. These reservoirs experience cyanobacterial blooms that impact water quality. MWD has utilized copper sulfate (CuSO4) as a treatment tool since the 1980s to control blooms. The amount of CuSO4 applied in these treatments has been substantially reduced by employing a monitoring network for early bloom detection and by targeting specific characteristics and growth habits of individual cyanobacteria. This approach is illustrated by the contrasting CuSO4 treatment strategies used to control two common 2-Methylisoborneol (MIB) producers (Phormidium chalybeum and Planktothrix perornata) and a toxin producer (Microcystis aeruginosa). P. chalybeum forms soft benthic mats in shallow water, and MIB events caused by this organism can be effectively treated with localized application of a small amount of large granular size CuSO4, which sinks to the sediment where the organism resides. By contrast, P.perornata tends to be widely distributed in the water column and requires a larger dose of fine granular size CuSO4 applied across the reservoir for effective control. M. aeruginosa can be treated with a smaller dose of fine CuSO4 since the bulk of the population is located near the water surface. The techniques utilized by MWD demonstrate how CUSO4 can be used to effectively control cyanobacterial blooms and their metabolites while minimizing environmental side effects.
Spoo-Chupka, M. K., Metropolitan Water District of Southern California, USA, MSpoo-Chupka@mwdh2o.com
Time: 11:00 - 12:00
Location: Poster/Exhibit Hall
Presentation is given by student: No